Lml duramax low fuel rail pressure no start. The truck cranks and sounds fine but will not start.
Lml duramax low fuel rail pressure no start The fuel pressure sensor provides a voltage signal to the ECM to Apr 5, 2021 · 6. went to start and all crank no start. There is an obvious power loss felt in the acceleration as well. Showing no injector pressure. With the change fuel filter light on. Jan 5, 2023 · Hello, 2011 Chevy Duramax 3500HD I’m having an issue and seeking help. 5-2005 (LLY) 6. Metal will flow throughout the fuel system. Jan 3, 2025 · Fuel rail pressure never goes above 300. The 6th time I stomped on the throttle (mad as hell) , engine shuts down instantaneously. Start with fuel rail pressure regulator check. both say my fuel rail pressure is too low, and 1093 says its too low during power enrichment, what ever that means. I've cracked lines at the injectors and I'm getting Fuel there. Then when trying to start I was only getting 600psi after about 5 seconds of cranking. (like in the video. Oct 31, 2016 · Then see if rail pressure will reach 21,000 PSI at idle, if it does then the low rail pressure under a heavy load is usually caused by a bad high pressure pump. If the fuel pressure does not go to 0 MPa (0 psi), test the FRP sensor signal circuit and the low reference circuit for an open. Actual Fuel Rail Pressure should be equal to the Desired Fuel Rail Pressure. ) Nov 2, 2021 · Cold start was fine. I hooked up the scan tool and got P0087. Also rail pressure is only around 1 mpa Mechanic's Assistant: Have you checked the engine's fuel supply? Are the spark plugs, fuel pump, and ignition all working? Sep 12, 2008 · Rodger 07 classic crew cab long bed 2wd 2500 700,000 miles BITCHES!!!!! Rotella T oil. Jan 18, 2022 · Right at about half throttle 2300 rpms my CP3 swapped lml has a very rough and jumpy acceleration right before the torque converter locks. Hand priming the filter head assembly does not appear to build pressure, despite it being replaced a In the event of a rail pressure control issue (typically low rail pressure) on an LML or LGH Duramax, GM test procedure specifies that an injector return line plug (GM special tool # CH-50377) be used as part of the diagnostic process. Jul 7, 2021 · I have a 2015 lml and I’m getting a p0087 low rail pressure code under hard acceleration, rail pressure stays with the desired pressure until 23,000 then the desired will go up to 29k as the actual rail pressure won’t exceed 23,500. Dec 15, 2024 · Chevrolet-GMC Diesel Diagnostics Look in the LML section. Anyone got any ideas? P0087 Fuel Rail Pressure Too Low See Hard Start/No Start above. 7psi during most of the cranking's and when it did start the rail pressure was moving around quite a bit. The FPR (fuel pressure regulator) mounted on the top of the CP3 is a solenoid, regulated by the ECM, that limits the fuel pressure allowed beyond that point in the fuel rail. May 23, 2022 · The CP3 pump always creates full pressure, 20K+. Aug 20, 2017 · You should be able to look at the desired fuel pressure and the actual fuel pressure with a scan tool. 7 #3 -. Unscrewed the bleeder and it took two pumps to get fuel flowing and the fuel appeared to have air bubbles in it. My guess is you problem is relate to communications. I was getting the p0087 code then going to limp mode. Test for less than 5 Ω between the Fuel Rail Pressure Sensor Low Reference circuit terminal 1 and ground. From at stop at wot, it'll hold 29-31kpsi no problem but as soon as it shifts into 4th, it starts surging. Check Fuel Rail Pressure (FRP) sensor voltage in scan data, key ON, engine off for 30 seconds. One day I warmed it up for 15mins and shut it off, not needing it that day. New cp4 and injectors from bosch new lines cleaned everything to do with fuel system install fass lift pump prime system no rail pressure. No change. Here is some info of my Duramax 2008 LMM 177k HSP egr delete and Y bridge Fass Titanium 165 S&B cold air intake Kbdp hot side intercooler pipe Race fuel rail plug I just saw this thread and figured I'd add my experience to it. 2015 lml duramax won’t start. Then ECM uses that information to Mar 21, 2016 · The rail pressure gauges plugs into a sensor on the rail iirc and reads off of that. Jun 4, 2021 · Are you asking for the fuel rail pressure at idle or fuel pressure from the lift pump at idle? The LML has an idle FRP of 4. Feb 13, 2022 · However, after priming the fuel system + bleeding the air and trying to crank it several times, the fuel rail pressure will only stay around 200-300 psi. Progressively got worse to where cold start is long crank and hot start is a no start without starting fluid. Customer: crank no start2011 lml duramax. Nov 25, 2023 · ENGINE NO START: Note: For intermittent no start or no start with ambient temperatures below –6° C (21° F). On a side note, all dynos are different. Have LML after CP4 died (metal shelves were found on pressure regulator filter). Mine goes into limp mode when I’m pulling a heavy load too fast up a mountain. Remove fuel pressure regulator on CP4, no shavings, reinstall. The desired FRP is around 4000-6000 psi if I’m not mistaken Jun 11, 2012 · Is the big brass schrader valve at the top front of the engine low pressure or high pressure (rail pressure) fuel tap? low pressure line to CP3, check with vacuum gauge She ran yesterday with what seemed to be good rail pressure (4K-5K psi at an idle and 18K+ psi under light load) but this morning it refuses to start :help. Problems in your car’s fuel lines are one of the main reasons for causing low fuel rail pressure on a Duramax. Jul 7, 2022 · Leaving for vacation in 2 days. It’s currently throwing code P0087-fuel rail low pressure, I also got code P0191-Fuel rail pressure sensor performance it will only start off starting fluid and will run and drive fan afterwards. then next day crank and no start. Possible causes of no fuel rail pressure on a 2012 LML Duramax with a brand new engine. 3 #2 1. Dec 6, 2024 · Truck was brought to me, crank no start. Just some rambling thoughts to consider. Oct 23, 2019 · Im working on a 2012 lml denali, it has a cp3 conversion, egr/dpf/def deleted, fass pump/stock filter delete. disconnected the return and watched as I cranked and it is pumping out a lot of fuel. 1982-1993 GM/Ford IDI 2011-2016 6. KOEO rail pressure is around 65 PSI. Idk Jul 9, 2017 · Had the same issue. We had no warning. 4 Nov 27, 2021 · I replaced the cp3, the fuel pressure regulator, the fuel pressure relief valve, and the primer bulb and still no rail pressure when cranking max it will get to is 250. First you need to find out why your not building rail pressure, Sep 6, 2015 · The Fuel Rail Pressure Sensor and the Desired Fuel Rail Pressure parameters should be within 690 kPa (100 psi) for the entire fuel pressure range. Changed CP4 to new CP4 (no more changed, cleaned everything, each injector was disassembled and very carefully cleaned) started engine from xxx times and found that my pressure regulator did not work (desired rail pressure is 30000 KPA, actual more than Apr 27, 2017 · Hi there, the incorrect cal would not cause a no start condition, but bad miss will occur, glo plug is self explanatory, same as its predecessors, still will not cause a no start. Engine cranking for 15 seconds. 1 day ago · 2. 5r20, DPF Delete, 5" Flo Pro Downpipe Back, EFI AutoCal Kory Willis, Sinister EGR Delete, PPE 3" Downpipe, Res Delete, S&B Cold Air, FASS 150 Titanium LP, Sinister Sump, Insight CTS 2 Monitor. Aug 18, 2012 · Observe the Actual fuel Rail Pressure and Desired Fuel rail Pressure parameters with a scan tool. Can be caused by a restricted DPF or other exhaust components; P0191 Fuel Rail Pressure Sensor Performance This seems to be a common fault but root causes are all over the place (injectors, cp3, etc). Dec 12, 2022 · Run fuel hose with 5 gallon jug and splice into fuel hose that normally exits the fuel filter, close to CP4 as I can get I believe, no start, hardly sucks any fuel, but eventually fills hose, and get red diesel all the way through, and out main return. Mechanic's Assistant: Have you noticed an increase in fuel consumption? Jan 8, 2021 · Looking for some guidance on crank no start without DTCs. Really thought my CP4 was toast at that point but decided to prime it for some reason. Now attach a 3/8 hose to the fuel rail nipple, and stick the end in a bottle. Faulty fuel pressure sensor: The fuel pressure sensor is responsible for sending a signal to the engine computer about the current fuel rail pressure. It takes pressure on the back side of the injector for them to work. I am thinking I have air in the system still. If you watch it, a subtle throttle increase makes it shoot up to 24k psi. Fuel pressures should be the same for both parameters. Some air came out. Connect the gauge and start the engine. Feb 8, 2024 · I rebuilt the motor last summer and stupid me didn't replace any of the fuel system components other than maybe 2 injectors. Checked filter head for leaks - none. The desired rail pressure will cranking is around 6000 and the actual is 1550. Figure on using 50-55 PSI in the injector return line while cranking the engine to start. Mar 4, 2014 · An almost perfect comparison between fuel rail pressure and desired fuel rail pressure is found on low mileage engines. 1) (No Start) Disconnect the electrical connector and return line from one injector. no smoke will start for a few seconds with ether (glow/grid unhooked) seems like the injectors just arnt firing. Jul 27, 2016 · Thanks Ron. One possible cause of low rail pressure is an injector that is returning too much fuel back to the return rail Feb 23, 2021 · Installed an EXERGY Fuel Saver FAC; Replaced Fuel Rail pressure sending unit; I primed the crap out of the system and after a bunch of start sessions it started > got a little choppy and died. Efilive says I have 229 lbs. A minor ripple is acceptable behavior for the fuel rail pressure regulator and is seen on high mileage engines. Clear everything and comes right back as soon as I pull the hill in front of my shop. Quick is I can clear the code with a $60 scanner from the parts store while still in tow, then I slow down. Any high pressure gauge that reads out to 30k would work I assume if you have one laying around. Dyno'd 643 RWHP. Pulled the feed line off above the drivers rail and lift pump is working fuel sprays pretty good out of feed line. During cranking fuel rail pressure builds up quick, well past 50 Mpa, and follows right along with the desired rail pressure. Most commonly sets due to an aftermarket air filter or intake kit/modifications. In this video I walk through diagnosing a P0087 trouble code on a 2006 GMC Duramax. I'm at a loss. after several dozen tries to get her to fire up we decided to crack an injector (#8 to be accurate) No fuel was coming out there. 5k then levels out at 6k while cranking. Short version: Engine cranks but will not start. My data logs are showing that my fuel railpressure is constantly going above and below the commanded rail pressure at the exact time I felt the fluctuation. Bone stock 2013. Jan 17, 2017 · I had a real similar set-up on my previous truck and kept throwing low fuel rail pressure code P0087 (at 50-100% throttle position) immediately after fuel upgrades. Fuel rail pressure is solid (Desired vs Actual) according to my EzLynk AA2. Nov 4, 2015 · 2011 2500HD Denali Duramax - Leveled, 33x12. However, the fuel regulators on the CP4 pump and fuel driver side fuel rail are new. This does not change at all when cranking. Jun 12, 2013 · Basically, your CP3 pump "sucks" the fuel from the fuel tank, if you have any air leaks in the fuel system, it will lose prime, if fuel lines get soft and collapse, you will fuel limp it. Batteries are new with full charge. 6 Duramax. Buy new ECM, can now see Rail Pressure. Fuel regulators 1&2 have been replaced. The fuel pressure should be 0 MPa (0 psi). 6 LML and it cranks but no start and it’s showing no fuel pressure the truck was brought to the shop because it lost power and turned off we changed the high pressure fuel pump we primed the system and everything and it cranks and it’s showing about 600psi in the fuel rail pressure sensor It’s A Silverado 2500 6. If it is leaking then it will need to be replaced. 6L Duramax. Install went smooth. Now drive the truck hard-- with several wide open runs-- if there is any fuel in the bottle the FPRV [fuel pressure relief valve] is leaking main pressure from the fuel system. 6 duramax I Mar 29, 2009 · Hey guys, thanks for looking. Here's what I've done so far: Research on this site lol; Added 5 gal of diesel to tank (even though I'm at 40% full on the gauge) Swapped my FASS fuel/water filters; Primed stock fuel filter before and during Mar 30, 2016 · customer complaint- truck had loss of power when driving under any load or throttle more than cruising. Got it all done and the truck keeps rail pressure but when it warms up after driving it will not start back it just turns over and will not build rail pressure. 3k and without ether wont even try to start. I have already replaced fuel rail pressure sensor and regulator on the rail again. The engine light came on. I have been fighting low fuel rail pressure for years. Dec 16, 2012 · 2004. Locate the fuel pressure test port. Mar 19, 2015 · Parked on a hill with low fuel and I think I got air in the system. It starts and runs great but at moderate to heavy load in 4th 5th and 6th, it surges like crazy and my rail pressure bounces all over the map. You need at least 2000 psi on crank and 45 psi return line reassure to fire the piezo. Jan 1, 2012 · 2005 Silverado EC/SB, LLY, 4WD, Edge CTS w/ EGT probe, LML Exhaust Manifold, PPE shimmed FPRV, Banks LBZ air cleaner, Profab intake, LBZ Turbo Mouthpiece, Kennedy twin lift pumps w/ megafilter, Corsa 304 SS Exhaust, Mike L tranny cooler, EXAXT Steering System, Redhead Power Steering Box w/ Amsoil PS fluid, Green Torsion Keys, Allison Deep Pan w/ Suncoast Filterlock and Transynd ATF, Bilstein Apr 5, 2022 · The fuel rail pressure sensor reads 7,800 psi when cranking and drops down to about 171psi when key on engine off. Mar 24, 2020 · Shut down truck, restart. No idiot lights, hooked up my reader and it showed no codes but indicated no fuel pressure. Mar 13, 2022 · On ’11-’16 Duramax trucks not equipped with a lift pump, a failing factory sensor will yield you a long crank, no-start scenario due to the fuel system losing prime. I put a new mprop on it while I was there, still the same issue. And no restart issues (yet). A vacuum leak could prevent starting. My fuel rail pressure while cranking is great when the engines cold but when hot the pressure builds up to around 1200 then won’t go up anymore. No issues until highway speed, same event occurs. If greater than 5 Ω Test the Fuel Rail Pressure Sensor Low Reference circuit for an open/high resistance. Feb 24, 2024 · Still has the low rail pressure code and map codes. Fuel is getting to the filter, cracked the bleed screw and pumped the primer a few times, fuel dumped out. problem- When I go on the highway after about 10 minutes it goes into limp mode and says fuel pressure low during power enrichment. The turbo is making boost and visually looks good with no internal oil residual. Disconnecting the FPRV will command the pump to full rail May 23, 2024 · Ill continue with my truck and the issue its a weird one that has had me stumped for weeks I have a 2500hd lmm duramax with a tuner and some spicy tunes +90 tow tune +150hp street tune +175 performance tune its deleted has new injectors ppe race plug I like to beat on it a bit its fun ya know how it is truck gave me my first p0087 low fuel rail Aug 6, 2020 · No codes. My truck only has 130k miles and has always been garage kept since new. I recently suffered with the dreaded "low fuel rail pressure" code, fuel filter 0% issue when towing 13,000#, but only on hills, and only when ambient temps were over 80*F. 2012 2500 gmc. 2013 duramax fuel rail jumps to 101 psi but mostly stays at 29psi. Nov 16, 2016 · So had a CP4 take a dump in this 2013 LML. Connected the Aug 10, 2020 · OkDually: Tell me more. fuel rail pressure while cranking is 4500 +/- . it will crank but will not start, no engine codes. fuel rail pressure at startup will barly reach 1500 psi but when started it runs just under 5000psi at idle and up to 26000 running down the road. IMO you have a electrical problem. Changed filter. 5L Diesel Engine Duramax First Generation: 2001-2004 (LB7) Duramax Second Generation: 2004. Hooked up snap-on scanner and had good transfer pump pressure and line pressure, but no rail pressure. I just replaced the fpr on my 2013 duramax LML with a kyntex upgraded regulator (better screen). If there is not, proceed to checking/replacing the high pressure pump. The actual pressure in the line varies along the line as a result of flow rate head loss. Thoughts? AFE PG7 drop in filter, stock air box, afe intake tube with 2nd vane in upper hose, HTT 2. I first put in a race plug (cheap and easy) as my lmm has 305,000 on it. 5 (LBZ & LLY) Top Contributors this Month Mar 22, 2016 · An almost perfect comparison between fuel rail pressure and desired fuel rail pressure is found on low mileage engines. The following factors are responsible for causing low fuel rail pressure on a Duramax: Factor #01 Fuel Line Problems. 6psi at rest. We have fuel all the way up to it. 5k psi at the fuel rail while cranking though it is only getting about 1k to 1. I have a P0193 code for fuel rail high pressure sensor signal high. Nov 24, 2018 · OK here's the situation 2012 LML bone stock 180xxx cp4 grenades like usual. Spent Friday trying to diagnose and fix by changing fuel filter, fuel line, then fuel filter head with no luck. Removing The Factory Sensor Installing LinCo’s fuel pressure sensor fooler requires an Allen wrench or socket, a 5/8-inch or 16mm socket and a 5/8-inch wrench (to remove the Mar 8, 2017 · 2011 Chev 2500 LML 86k miles Deleted in 2015 Running great until last week. 8 #5 -0. Apr 21, 2021 · Immediately thought my stock CP4 had shit the bed. I have a 2008 LMM . DTC codes P0087, P0093 or P1093 may set due to low rail pressure. May 11, 2021 · You have good Rail PSI at around 5K PSI, unplug FCA to max out your Rail Pressure, if it does NOT start and rail Pressure while cranking is above 2200PSI the Rail sensor should be sending signal to ECM to fire the hot hole. Truck ran great prior, decided to do gaskets and studs so we could turn up the 366 a bit. To narrow down your no-start condition to an FPRV, you can log commanded vs actual rail pressure and look for a low fuel pressure condition, but that symptom won’t Feb 5, 2018 · The repairs were made to fix the air leak and the truck was test started. Mar 19, 2015 · I've tried with my tune prior to install, as well as with my tunes for the build with no success so I don't think its a tuning problem. The only fault I can discern as a cause now is the "fuel pressure regulator 2 control circuit short to ground fault" shown in the obd2 scanner. We tried replacing sensor on firewall side of driver side rail per some diagnostics found on some forums. Your Duramax relies on the fuel rail pressure sensor (FRP) and fuel pressure regulator (FPR) to maintain optimal pressure. This process repeats 5 or 6 more times. Check the fuel lines and filter, and ensure the lift pump is functioning properly. Since the amount of fuel being squirted is primarily controlled by the injector pulse width I am surprise the return rates can get bad enough to cause the fuel pressure to be too low. Air Intake: Verify that the intake is properly connected and that there are no leaks. 5 turbo, AFE e-mani, ATS Arc Flo, 50HP DDP , 499K, HPTuners, G56, 25. Dec 5, 2012 · The PCM appears to crank up the fuel pressure in anticipation of any possible load increase. Compare readings to manufacturer specifications. Cranking is definately not one of this conditions. our 2011 has a fass lift pump so I know its getting fuel to the CP4 but I don't know if that is doing anything. Replaced-fuel pump because of weak fuel pressures and replaced both fuel regulators after some diagnosing pointed to them being possibly faulty. LML no fuel rail pressure LML Duramax, Diesel, brand new engine Oct 8, 2019 · Hooked up bluetooth scanner and read codes P128E & P0088 (high fuel rail pressure) reset the codes and took it for a ride. Feb 26, 2021 · Loses rail pressure, power, and puffs out blue/white smoke from exhaust? The truck only starts cold. Aug 25, 2024 · To troubleshoot P0087, you need to test the fuel pressure. The filter prime button is soft. Sep 9, 2014 · Just wondering if anyone here has run into this yet. Replaced fuel filter housing that night . 8 MegaPascals (MPa), or 160 to 261 pounds per square inch (psi). Still noting. Nov 24, 2018 · 2009 Silverado 2500HD CCSB LTZ Diesel FASS 95 Lift Pump (with Baldwin filters), Edge Evolution CTS2 Monitor w/Dash Pod Mount, Factory FF as Tertiary Filter, Bilstein 5100 Stock Height, Steel Diamond Plate Bed Rail Caps, AMP Research Bedstep, Fumoto oil drain valve, PS Oil cooler, Pioneer AVIC 7200NEX GPS/Stereo, Air Lift LoadLifter 5000 Air Bags. 15 secs of cranking gets 19 ml of fuel on main return. A faulty FRP sensor can send incorrect data to the ECM, triggering P0087. No oil. I then replaced the whole filter housing and then put on a car fuel filter with the adapter, still didn’t fix the pressure. Pressure is not what is needed from the lift pump, flow is what is needed. I’d check the injector rail pressures and be sure the injection pump is putting up good . Injector balance rates all look fine and there are no "related" codes present EVER. Jan 4, 2019 · hello guys Im hoping maybe I can get some incite on my issue, the truck is a 2001 duramax was given this job initially it was a hard start then it went from a hard start to no start, so I was instructed to replace the cp4 pump and injectors so i did that now I have 304 psi on the fuel rail, I have disconnected the fuel pressure regulator and it jumps to about 390 but that is max. I was leaning towards the filter head needing rebuilt but it would still hold some rail after it being primed until it softened up and died again. Sep 27, 2022 · no smoke and when it gets running it runs and idles fine fine at a constant 5k to 5. Apr 27, 2017 · You can check the driver side fuel rail relief regulator, by removing the rubber hose and verify it's not leaking by on crank, regulator 2 as it is called is located on the front driver side fuel rail. Connect a fused jumper between the FRP signal circuit terminal 2 and the low reference circuit terminal 1 and observe the Fuel Rail Pressure Sensor parameter with a scan tool. So knowing that, you have to find the culprit, flexible fuel lines soften over time. Oct 11, 2021 · Low rail pressure is one of the most common cause of a limp mode in the 2001 – 2010 6. Jan 29, 2023 · I have cracked the fittings on both rails and cranked the engine until fuel and no air bubbles are present at each rail. Had to borrow a buddies truck to finish the trip. 6 LML. Oct 21, 2020 · My fuel tank has been full when this code has been popping up and my fuel filter only has like 700 miles on it. If rail pressure matches desired, diagnose other codes that may be related to starting problems. Fuel rail pressure caps out at 16k and desired is around 28k. ) I saw a YouTube video of someone removing the bleeder screw and priming (cheap plastic, for the record from GM :surprise Primed truck, tried to start - did not work. Took to dealer, scan tool connects, but can't look at fuel pressure data, crashes when trying to look at rail pressure. 8 MPa with key on and engine off. No visible or audible air leaks. 6 LML and it cranks but no start and it’s showing no fuel pressure. My truck has been sucking in air from deteriorated flex lines from the tank so I replaced it with a 1/2" fuel hose from the tank directly to engine bay the quick disconnect rigid line. There is no fuel pump on a DMAX. Subject: Duramax Diesel Hard Start, No Start, DTCs P0087, P0088, P0191, P128E or Injection LML or LGH) Silverado 2500/3500 GMC Savana Fuel Rail Low Pressure Most times the problem shows up as letting the truck sit overnight with a no start in the morning. Then bled the Schrader valve. Aug 2, 2023 · The cooling system pressure tests great and I am confident my fuel is not contaminated. 08 #4 1. Jan 19, 2021 · LML No Fuel Rail Pressure. Replaced pump and truck started and ran great and drove great. Seemed fine, but when I stood on the gas it wouldn't go over about 2900 RPM then check engine light with reduced power mode, and change fuel filter message. after cranking for a few seconds fuel rail pressure on the scanner shows 6,000-8,000 psi. 4kpsi Your lift pump should be putting out about 10psi, much higher than that can cause problems. If they match and the fuel pressure is low, it's the controller not requesting full rail pressure. 5) Check fuel return from the high pressure limit valve or fuel pressure relief valve. Jul 5, 2022 · If your CP4 grenaded you need to also replace the fuel rail, injectors, and completely flush the fuel system from tank to CP4 and return lines. The last few days, my truck has lost power and died twice. Still no luck. So we cracked the line on the back of the cp4 going to the fuel rail and no fuel there either. P0089; The engine control module (ECM) uses commanded fuel pump flow to determine a desired fuel rail pressure (FRP). later Lml duramax low rail pressure after headgaskets job. Installed ported fuel rail fitting and race FPRV and no more issues for the remainder 2 yrs I owned the truck. Feb 19, 2024 · I have a 2011 Silverado 3500 with an LML 6. I do not smell fuel or see any black smoke while cranking. Also, the injector pump (CP4) is not dead. I am getting fuel returning which seems strange no fuel coming from the pressure side of the pump AT ALL during cranking. So heres what its doing, driving like normal the other day at low speed and low rpm, it started kind surging, right away i stoped and put in park and turned the engine off, tryed to start, it fired up for prolly 5 seconds max then died and havent got a sign of life sence. Check for ECM updates; May cause the engine to go into a limp mode. 1 (or FRV1) on top of the injector pump. Confirmed all sensors are plugged in and have good connections. No codes. When I started looking I found that the original fuel lines were pinched. Have replaced entire fuel system, sending unit to injectors, lines included, Waterpump, hydro boost, besides that truck is factory original except ujoints and brake pads 3. Came back and shut the truck off and tried to restart and it wont start. Same codes. Start by using a fuel pressure gauge to measure the pressure at the rail. Then I noticed no oil pressure while cranking. I have a constant P2294 and P2295 fault code. No codes set. 3 - 4. Sep 18, 2015 · So here is the issue #1 , When i accelerate hard on my level 3 of 4 tunes( street tune) my fuel pressure went from 30k PSI on my Fuel rail pressure to 2. The lowest pressure is going to be between the filter (biggest restriction) and the CP3. The system was loaded up with air so I made up an auxiliary tank to the inlet of the filter housing, primer pumps hard after 4-5 pushes. I pulled the mprop off the cp4, perfectly clean. Don't overheat your starter!! With that information, you know that your ECM is demanding enough pressure to start, and that fuel pressure is not being produced. It was running fine and the first message was change fuel filter. I just finished my cp3k conversion on my lml. Jan 30, 2022 · Ran across a no start issue w this 2016 LML duramax following a cp3 conversion. LML engine with 114k on it get it installed and can’t get it to start. Customer: How are Chris I have a 2015 duramax 2500 with a 6. The first psi gauge I installed was off my liftpump, that’s when I found my LP was only putting out 6 psi, instead of 8-10. Fuel rail pressure sensor has been replaced. Cranking rail pressure is around 1500 PSI, which explains why it won't fire. Had it towed to a shop and they checked fuel pressures and found the CP-4 wasn’t putting any pressure up. Dec 27, 2013 · The engine control module (ECM) controls the high pressure fuel pump pressures by using two fuel pressure regulators, fuel pressure regulator 1 is located on top of the high pressure fuel injection pump and fuel pressure regulator 2 is located at the front of bank 2 fuel rail. Oct 7, 2015 · 2005 Silverado EC/SB, LLY, 4WD, Edge CTS w/ EGT probe, LML Exhaust Manifold, PPE shimmed FPRV, Banks LBZ air cleaner, Profab intake, LBZ Turbo Mouthpiece, Kennedy twin lift pumps w/ megafilter, Corsa 304 SS Exhaust, Mike L tranny cooler, EXAXT Steering System, Redhead Power Steering Box w/ Amsoil PS fluid, Green Torsion Keys, Allison Deep Pan w/ Suncoast Filterlock and Transynd ATF, Bilstein It has high fuel rail pressure at idle but low when you rev it up. I have read that this can be caused by low or no fuel as well. Mar 6, 2021 · The engine cranks strong and fuel pressure builds in the high pressure rails. If you don't replace those parts and flush the system you'll have metal floating through your fuel system causing more damage Jan 1, 2020 · I replaced the fuel filter with the same one a racor R90s. The truck cranks and sounds fine but will not start. Hot start had long crank. if you let it sit for about an hour it will fire up. This is my first Duramax and I’m having a crank no start issue. Truck hit 300k miles last week, and developed a fuel knock while towing a vehicle back to my shop. Dec 14, 2022 · Pinched return line, still no start. Provide information if you can. I hope that is clean, then I will figure why rail pressure drops. 73 rear, stock tire size bully dog , 5 inch turbo back, with 6 inch tip. 9k turn the key to run I have 0 psi I start cranking and quickly builds to 6. The fuel pressure regulator 2 outlet volume test must be performed while the no start condition is present or incorrect diagnosis may occur. For instance, if all the injectors passed the test, but the ecm wasn't commanding enough fuel pressure to fire the injectors in the first place then that would render my test pointless because injectors weren't seeing Mar 2, 2015 · shaped 3/8 hose-- remove the hose from the fuel rail-- and plug the hose. Dec 9, 2013 · 2013 Silverado 1500 275/60R20 AXTs, 2" level, UnderCover Flex, BedRug, WeatherTechs 2015 GMC Yukon XL SLT - SOLD Husky Liners throughout, HID lows, LED fogs Jun 2, 2017 · Its also a matter of not being able to see desired/actual fuel pressure, and see what the regulators are doing as well. I connected a test light to pins 1,25,49,73 and the other end to battery ground with no voltage signal to fire the injectors. Jun 15, 2021 · Also bled the schraeder valve at the front of the motor. Cranks but no start. primed a bunch and got going. That did not solve anything. Observe the volume of fuel from fuel pressure regulator 2. Messed up gauge and ran out of fuel. Jun 20, 2009 · This is not normal. May 28, 2020 · I would have expected max rail pressure and no change, no start. Rail Pressure is demanding 5. truck ran fine for 2 weeks. i just replaced the fuel filter with a Jan 3, 2018 · 7) Confirm actual versus desired rail pressure even under crank no start conditions, to confirm the starting issue is rail pressure related. Rail pressure per SDS while cranking is only about 65psi. The fuel rail pressure sensor has a 5V supply, Ground, and Signal wire. Also, it seemed most of the threads were in regards to trucks that run and start with only a handful of the threads involving a no start situation. Feb 6, 2015 · I removed the fuel regulator valve and there was no metal debris, so now I will check the fuel regulator valve no. Dec 24, 2018 · Unplug the fuel pressure regulator 2 (pressure control valve in left hand rail) electrical connector. A mechanic checked it out and said no vacuum leaks in the fuel lines. fuel rail pressure. Use a scan tool to monitor live data: at idle, rail pressure should be 5,000–6,000 PSI. I found out that the P0193 Fuel Rail Pressure High Voltage code is actually fir Low Fuel Rail Pressure. Not sure what to do. When cranking my DFRP does not seem to match actual. Oct 28, 2021 · Ran good and strong during the check out and 4 hour trip home, but 30 minutes into the start of a 1200 mile RV relocation trip, had the low fuel pressure limp mode experience like you did. ⇒ If the fuel rail pressure parameters at idle is within 690 kPa (100 psi) and is not within 690 kPa (100 psi) at 1800 RPM, replace the Q18A Fuel Pressure Regulator 1. I try priming the fuel on the filter head, but it loses pressure after a few seconds. I then bled the air out at the filter housing. The EGR cooler has to be removed to get to the line where it connects to the fuel rail. They went away momentarily after cracking and bleeding the fuel rails, but then came back at the next startup attempt. How are Steve I have a 2015 duramax 2500 with a 6. also I can The factors that are responsible for causing low fuel rail pressure on a Duramax are not few. The fuel rail pressure sensor tells the ECM what the pressure is in the fuel rail. Jun 10, 2011 · 2500hd 2002 lb7 130,000 miles. Or you could still have some air in the system. 5K, displayed on my EDGE CTS. Feb 17, 2017 · Hey all, Did some work on my 04. No start. Test the Fuel Pressure Sensors. Feb 27, 2019 · LB7, LLY, 01-04 At key ON, engine OFF, fuel rail pressure should be 1. 2015 Chevy 3500hd lml duramax. Truck has been def deleted with a basic tune, and has run flawless for the 3 years that I've owned it. Plug the fuel return Jun 20, 2024 · Welp I’ve looked everywhere trying to find a video or tutorial on how to change out the fuel rail pressure sensor on my 2011 lml duramax. Rail pressure is 24. no codes. Jan 3, 2025 · I have a 2011 lml duramax and I can drive it and accelerate without it bogging down but when you heavily accelerate, it Boggs down but doesn’t die. It has done this at 20K once, but not since i changed the filters. I managed to figure out how to prime the fass as it seemed to have air in its lines. I got running again and used air to blow out tank. Once the coolant Temps are above 90-95 degrees, it won't build rail pressure. 1 to 1. Proceeded to replace high pressure fuel pump, lines, hoses and all 9 injectors per GM bulletin. Changed fuel filter - no change. Even though it says “reduced engine power” I still have full power. Then shut off one day and it wouldn’t start. Max fuel rail pressure at cranking is around 400 psi, obviously not nearly enough and something seriously wrong. Feb 7, 2021 · I’ve tried everything I know to do, primed the filter housing, drained it again and reprimed it, I made sure the cp3 gear was tight and spinning the pump as my dad tried to start the truck, I pulled the plug that blocks the 2nd feed line that the cp4 used on the passenger fuel rail and fuel was coming out as we cranked it. Aug 4, 2023 · Note that once fuel is drained from the fuel rails, it may take several (4-5, maybe more) instances of cranking the engine for 15 seconds at a time, to produce the necessary rail pressure. Nov 14, 2022 · Getting a low fuel rail pressure code when getting on it. So i changed the fuel pressure sensor and pigtail, as well as the drivers side rail with regulator. Apr 28, 2023 · Hello all. Still low rail pressure and truck still wont start. 6L LML – LGH Duramax PDF: 2011 – 2016 6. I have replaced both 2012 LML no fuel rail pressure LML Duramax, Diesel, brand new engine, 2012 Apr 12, 2015 · I went in and done a Wehrli cp3 conversion with IC pipes, EGR/DEF delete, AFE intake, Kory's tunes 150 fass and a sportsman cp3. 5 - LLY Silverado 2500HD 4x4 CrewCab Suncoast Stage V and 1056 converter - Air Dog II 165 - PPE Race Fuel Valve -HSP Turbo Mouthpiece - Modded Stock Airbox - Banks Hot Pipe - ProFab Downpipe - Diamond Eye 5” Exhaust – Edge CTS3 - Cognito Pit and Idle arm braces - PPE Tie Rod sleeves - DuramaxTuner Spade King - ARP Head Studs with C gaskets – PPE Fuel Line – LBZ Inj pump Dec 17, 2021 · It’s said however, that once the FPRV bypasses fuel a couple times, the valve can become stuck open, and when this occurs, you’re not going to build any rail pressure. When I purchased this truck I changed the fuel priming housing assembly and filter due to it leaking and the truck was also sitting for 2 years. Deteriorated fuel return line coming off the drivers side fuel rail, identified in the OP's diagram as item 19. If out of range replace the rail pressure sensor. 065 mpg, exhaust & turbo blankets Customer: 2011 lml duramax, crank no start. Jan 16, 2023 · Installed Exergy Fuel Saver New fuel pressure rail sensor New filter Cleaned fuel lines New fuel Sending Unit Primed it couple times it started for 2 seconds on the 5th crank with 4k psi on the fuel rail, now it’s at 40-70 psi at fuel rail Checked fuses already Everything is plugged in correctly No fuel codes in system Oct 12, 2021 · Best wishes for all! Kindly ask about some expert opinion. Don't see any fuel leaks everything looks fine. Also, truck was taking about 10 + seconds of cranking to start, obviously losing prime. sucked gas tank in because of cap not venting . if you shut it off you have maybe 5 minutes before you would have to start it with ether again. May 4, 2021 · Your either bypassing to much fuel back to tank, or injector pump is bad. And I've replaced fuel pressure regulator - Answered by a verified GM Mechanic Jul 22, 2015 · DMax NO START ! PLEASE HELP Hello, ive read every post on every forum and still havent had luck fixing my DMax. fuel filter housing replaced along with all rubber fuel lines with heavy duty fuel lines because of TSB on issues with air leaks in them. Checked all fuses and no codes other than a link data code. 5 lly (y bridge, new oem lbz fpr, gaskets & studs) and now fighting a no start. I have since replaced all rubber fuel lines around the filter head, replaced the filter head + filter itself, and tried shimming the FPRV but am still stuck at a FRP of 200-300 psi. Nov 20, 2024 · Everything I’ve replaced so far is the fuel filter head, the fuel pressure sensor (back of driver side rail) and the fuel pressure relief valve (front of driver side rail). Sep 12, 2017 · I hooked up my scan tool after confirming the lift pump was working and watched the Actual and Desired rail pressure PIDs. i shut the truck off and read/clear the codes with my hypertech programmer and it starts and is fine, but still throws the codes p1093 and poo87. Symptoms include hard start/no start, rolling idle, fuel pressure drop wi Feb 10, 2016 · After it would not start checked the fuel pressure and there was none. It's a crank, but no start. Sep 28, 2020 · 5. The oil gauge on the dash is pegged out at 115-120 psi and reads that as soon as we put the key in. I’m troubleshooting my 2015 lml, died on the side of the road low rail pressure P128e and the change fuel filter message. Sep 9, 2022 · It just shut down right after we pulled out of a rest stop. And we’re getting a code that says fuel rail pressure to low only when we heavily accelerate which we should be able to do. Checked for fuel, it was getting fuel (not a gel issue, as I suspected. Thank you, G Nov 8, 2018 · As you accelerate the fuel psi will drop a little, just the opposite of the way fuel rail pressure works. ⇒ If the Actual Fuel Rail Pressure is less than the Desired Fuel Rail Pressure, refer to Fuel System Diagnosis - High Pressure Side . You should not have 5V on any 2 wires at anytime unless you have 29,000 plus psi of rail pressure. Jan 3, 2022 · Typical causes of low fuel rail pressure codes are: Leaking lines from tank to fuel filter (should be negated by a functioning lift pump) Clogged fuel filter (should be negated if you're changing them regularly) Weak fuel pressure relief valve Bad injectors returning too much fuel Dec 12, 2018 · I removed the wheel well and got to the fuel filter and fuel filter head assembly. Fastforward to now- truck mechanically sounds good had good power and such. ⇒ If fuel system tests normal, refer to Diagnostic Aids Customer: I've got a 2016 Duramax 6. The rail pressure was ~24. If the actual is lower than the desired, that would indicate a mechanical problem. Went to start the truck up and crank no start. On the LMM, LGH and LML engines, actual fuel rail pressure should be 35 to 40 MPa (5076-5802 psi) at engine idle. I still have no injector pressure. Crank the engine for 15 seconds and verify there is a steady flow of fuel from the fitting on the rail. Jun 8, 2020 · Looking for some input. I’m getting a crank, no start on my ‘15 LML. heres what Oct 13, 2014 · Just rebuilt the fuel filter housing, Replaced the hoses with clear hoses and bled the shit out of it and now my actual fuel rail pressure is 50 mpa and desired is 47 mpa but still no start. • No start Some technicians may find one or more of the following DTCs set in the Engine Control Module (ECM): • P0087: Fuel Rail Low Pressure • P0088: Fuel Rail High Pressure • P0191: Fuel Rail Pressure Sensor Performance • P128E: Fuel Rail Pressure Performance ⇒ Normal SI Diagnostics may be inconclusive or lead to Fuel Injection Pump Apr 24, 2018 · 4) Rail pressure should read 1-1. I primed it many times, not Oct 20, 2024 · 2011 lml with cp3 conversion no Lift pump. Removed fuel pressure regulator 1 and found a lot of metal on the regulator. I have a cp3 conversion, fass, and the stock filter and head completely removed. A "shark tooth" fluctuation in fuel rail pressure indicates a sticking fuel pressure regulator. When I first start the truck all the injectors are in spec at #1 -1. no DIC errors. 2L Diesel Engine Duramax Third Generation: 2006-2007. I looked at the engine data on the scanned tool, the FPR2 (fuel pressure regulator valve on the fuel rail) was first to loose pressure, then the rail pressure would drop, and at the end the FPR1 would reduce. Dec 14, 2012 · The same problem, the truck was running out of fuel after a minor pull. Figured someone could benefit from seeing what causes this condition and how Disconnect the harness connector at the B47B fuel rail pressure sensor. Nov 3, 2024 · Since it cranks fine but doesn't start, here are a few things to check: Fuel Supply: Make sure there’s fuel getting to the injectors. I am thinking the fuel system is airbound. 6L LML – LGH Aug 26, 2011 · You only know what the fuel pressure is at THAT ONE point along the line that is tapped with a sensor. P0101 MAF Sensor Performance. Replacing this line was a huge PITA. Low rail pressure could be caused by a restricted fuel filter, air in the fuel, a bad pressure relief valve, excessive return fuel from the injectors or a worn CP3 pump. The actual fuel pressure is monitored using the FRP sensor. Went to install a new sensor and tried to see if oil would come out. Saw a leak on the fuel rail and we tightened it but still did not solve the problem. It's throwing a fuel rail pressure low code with pressure fluctuating from 3300-9700psi. . AD sent me a new spring (no adjustment) that worked for a while, then they sent me a new motor. zci dpgvro rkktzy moc rsri khec lgg utbjx wsjz kevxn