I just changed the fuel filter on my 2012 2500HD, after installing the filter I primed it and opened the bleeder screw and let the air out, repeated this until only fuel came out, let the truck idle for about 8 minutes to check for leaks, none so went for a test drive, but in drive the trunk has no power at all, it acts like its in limp mode, in park it revs up without any hesitation, but in drive the throttle is just not there...no lights or info on the DIC, and no codes are set???
LML No power after changing fuel filter
- Thread starter r_olsen
- Start date
Watch rail pressure while driving to see what it's doing versus desired
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I believe I figured it out, rail pressure was fine, but there's air in the line from changing the fuel filter, primed it for a good minute and the trunk took off, drove around for a few minutes and it was fine, stopped and started and was limping again so I primed it again and all was good, drove around some more and no more issues. Thanks for the input.
I would pull it loose and see if you cut a seal or have something wrong. It sounds like your sucking air.
i lost the O-ring on my LMM fuel filter once and it did some very weird stuff before i found out the cause.
So I pulled the fuel filter off, checked the seal and it looked fine, wasn't pinched anywhere. I replaced the plastic bleeder screw with a new aluminum bleeder screw, tightened both down and then primed it until i couldn't press down anymore. Started the truck and let it run for 5 minutes while continuing to prime then went for a test drive, still no power. Shut off the trunk and primed it until I couldn't press down, let it sit for 5 minutes and went back and the primer was soft, it took about 6 primes and it was hard, let it sit and again it was soft, so air is still getting sucked in somewhere. So I thought about getting another fuel filter from the dealer and trying that, one question I have is could the primer mechanism have a leak?? Other than that or the filter not sure where air could be getting in from??
fuel filter heads are prone to leaking. i have not heard about it as much on the newer trucks but i would bet they still do. being this started after you put a new filter on, id be more inclined to look at that as the issue
Did you change the filter in regards to a power issue? Was it low before hand and in hopes of it fixing the truck? jw
Just curious, what does the fuel filter minder read now with this new filter? And I agree with James toss a cheap o-ring kit in that fuel filter head for piece of mind.
I like the kit Merchant sells with the aluminum WIF sensor plug and the aluminum bleed screw. Those plastic WIF sensors are prone to leaking and causing problems too. I agree with James though; since this started right after changing the filter, I would look at something related to that as being the cause.
So I just replaced the o-rings in the fuel filter head, but that doesn't seem to have done anything, it'll prime up hard and after about a minute its soft again so I assume air is still getting in. What I have noticed is if in gear, foot on brake, rev to 1000 rpm for 30 seconds it'll take off and run as long as the rpm's stay above 1000, the minute I stop and let it idle, which is around 600, air is back in the system and there's no power.
Just an update as I'm still having power issues but only at idle, had the truck into the dealership to reflash the ECM back to stock since I've had to add all emissions junk back on. At speeds above 1000 rpm truck runs fine, idles fine but when you drop it into drive no power and starts knocking, if I rev the truck above 1000 rpm for 5 seconds then it'll run and as long as I keep one foot on the brake when coming to a stop to keep the rpm at or above 1000 its fine, the second it falls below pressure is lost. Dealer said it was due to contaminated fuel, but if that was true wouldn't it run rough or stall or knock at higher rpms also? They also said if that wasn't the problem then it may be injectors, which they want 7500 to replace all 8. From what I've read online I'm wondering if there is a problem with the fuel pressure regulator that is on the front of the left side fuel rail, could that be causing this issue
