it is the front tank correct?
2015 GM 3500 6.0L - Need help with engine stumble
- Thread starter burbguy82
- Start date
Front is the primary tank
Of course, that one is 100 bucks more. It comes with the tank pressure sensor.
Got sidetracked, my daughters Tahoe all upon a sudden developed a pretty bad leak, worked on that today.
Thanks for the help BTW. I will post back after I get the new pump in. Man I need a lift.
With those negative fuel trims, your engine is running rich. Since you replaced the O2 sensors and injectors with original GM parts, the next thing I would check is the MAF sensor. What are your gps with it running at idle? Is your coolant temp sensor reading normal?
- Joined
- Sep 8, 2020
- Messages
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Not sure if this has it. I had seen quite a few of the 2007-2013 need the alcoholic composition sensor reset. They will cause driveability issues and no lights. Kind of an odd one to track down but had a few of them in my gm days
Well did that with success today. Guess what. Same thing. Factory fuel pump, from the dealer, by VIN.
Key on up to 65, then drops to 58 now, then at start back to 65.
I did find something a bit interesting though. I am eating dinner now, but wanted to reply to this ASAP. Headed back to the dungeon now to see if what I found had an effect. If not, explosives usually work.
Well did that with success today. Guess what. Same thing. Factory fuel pump, from the dealer, by VIN.
Key on up to 65, then drops to 58 now, then at start back to 65.
I did find something a bit interesting though. I am eating dinner now, but wanted to reply to this ASAP. Headed back to the dungeon now to see if what I found had an effect. If not, explosives usually work.
I did not, Strange as I monitor fuel pressure on many LSx engines & the pressure always matches the calibration as it's a key component in expected injector flow rate.
Starting to question the accuracy of the gauge?
Starting to question the accuracy of the gauge?
i guess. it is a mechanical gauge. i started to intermittently see random misfires on various cylinders, and fuel tank pressure show -91 psi on Hpt scanner ......which is impossible. i am starting to think it might be the computer. not aure how much else there can be. tank sensor was included with new phmp as an assembly fyi
i am going to see if i can save a datalog on hpt and send it too you once i get a chance.
I did find a fault with the evap vent valve. it was commaned open, and flow was checked with smoke, but i took the thing off and commanded it open.......it was not opening al the way, maybe 10%. i took the valve apart and cleaned it, now opening fully, but had no effect of fuel trim.
so new fuel pump, injectors, evap canister and purge.
i even swapped coils, and the "misfire" did not move.....although they are intermittent. engine idles smooth and runs smooth sometimes with very reduced power.
You have to set the PID's correctly in the scanner & save the configurations per vehicle/generation
found this, others and @clinebarger
https://www.gmupfitter.com/wp-content/uploads/2021/05/UI-Bulletin_-145_-Rear-tank-delete.pdf
it would seem that there is a vent failure common in these......I am getting intermittent -3-5psi reading in the rear tank.......
my rear tank vent tube is "clogged", but visibly intact. Is there a electronic valve on the rear tank unit that opens and shuts?
Could I not cut in a tee and the rear filler and run to the front tank vent tube?
https://www.gmupfitter.com/wp-content/uploads/2021/05/UI-Bulletin_-145_-Rear-tank-delete.pdf
it would seem that there is a vent failure common in these......I am getting intermittent -3-5psi reading in the rear tank.......
my rear tank vent tube is "clogged", but visibly intact. Is there a electronic valve on the rear tank unit that opens and shuts?
Could I not cut in a tee and the rear filler and run to the front tank vent tube?
That information is for diesel powered trucks that do not have Evaporative Emissions equipment & the tanks are simply vented to the atmosphere.
Your truck will have a vent valve, cannister, purge solenoid......The EVAP system may be doing a leak test when you see the negative pressure....See if the vent valve is commanded closed.
Your truck will have a vent valve, cannister, purge solenoid......The EVAP system may be doing a leak test when you see the negative pressure....See if the vent valve is commanded closed.
Good point on evap test.
It typically is not commanded closed under the condition. can be open or closed command.......ill get back
@clinebarger
I am also getting "lost comms with BCM" U0XXX.......just found this this morning.......I also get intermittent stabilitrak error, but never thought they would possibly be connected. Note "engine stall". Also a recent scan shows a code for radio and phone...........
I am going to take the dash pad out and check these this weekend.
I am also getting "lost comms with BCM" U0XXX.......just found this this morning.......I also get intermittent stabilitrak error, but never thought they would possibly be connected. Note "engine stall". Also a recent scan shows a code for radio and phone...........
I am going to take the dash pad out and check these this weekend.
That TSB has a bunch of supersessions, 18-NA-161 is the current bulletin.
I have seen the starter heat shield contact/bounce into the battery post of the starter with a few K2 1500's.
I have seen the starter heat shield contact/bounce into the battery post of the starter with a few K2 1500's.
It is amazing how much looking someone has to do sometimes to find such info these days.......for me the novice.
