Recent content by Potius

  1. P

    Misfires on one bank

    Well another update. Figured out the shudder I was low on trans fluid due to a small leak from pan which I have fixed yesterday while doing fluid and filter change as well as oil and filter change while I was under there. Did an exhaust back pressure test and at idle both sides were around 1 psi...
  2. P

    Misfires on one bank

    Wires are new genuine gm tested resistance even first. Plugs are newish at about 10k miles. Tried swapping coil packs and plugs back and forth with no change. Changed pcv early on with brand new one. Going to check injector wiring and clean up all ground points tomorrow for good measure as well...
  3. P

    Misfires on one bank

    Ok so fun update. Unplugged the range obd2 afm disabler for first time in 5 years and went driving around town. She runs a lot rougher with it unplugged and has harder misfires. Also seems it was blocking some codes being plugged in cause I got a few lol. Got a P3400- afm issue though it’s on...
  4. P

    Misfires on one bank

    Well took off the purge valve solenoid and tried to blow through it but wasn’t able to indicating that it was good and still closing. Going to try a power balance tomorrow and see if any noticeable difference in cylinders 3&4 where the misfires are. Got the new injectors from rock auto but made...
  5. P

    Misfires on one bank

    I don’t seem to have the injector balance on the scanner for the Tahoe but the running fuel pressure was 55psi. Gas is e10 standard cheap pump 85 octane. Scanner says 10% as well. Has been running lean since last oil change about 2000 miles ago so probably plenty of fuel in oil lol. I’ll change...
  6. P

    Misfires on one bank

    Here is 2 pics I took earlier today of fuel trims. Side note when I checked for vacuum leaks I did a smoke test from a few different locations. Also tried the propane test all around and for S&G also did the carb choke cleaner spray test all around.
  7. P

    Misfires on one bank

    Will check that next. Maf was at 6 g/s idle 600 rpms. 11.6 g/s at 1200 rpms and 18ish g/s at 1800 rpms. Maf readings seem to be within range and rise proportionally to the rpms ruling that out (hopefully) still cleaned it earlier. Haven’t looked at purge valve at all yet so will check that next.
  8. P

    Misfires on one bank

    Vacuum leaks was one of my first tests I did. Smoke tested from a few different spots and didn’t see any leaks
  9. P

    Misfires on one bank

    Side note I made sure to check O2 sensors and they are new and reading good and went with genuine gm. After all this I’m starting to think it’s time for a leak down test to see if I got a leaking valve. Course that wouldn’t explain the misfire on 3 AND 4 cause there on opposite banks….in just...
  10. P

    Misfires on one bank

    Ok so changed scanner to read g/s and went on a 100 mile trip. My maf seems to be sending some data and it does rise proportionally to the rpms when I’m not driving. When I’m driving mostly they are good. At idle reads 5ish/g/s when I double rpms the g/s double also to about 10. I still misfire...
  11. P

    Misfires on one bank

    What led me to unplugging the maf was the scanner reading. At idle it was .01 and at 3k rpms it only got to .02 I believe it’s in lbs/min
  12. P

    Misfires on one bank

    Yea I’ve given up hope of finding an oem one lol so I was thinking either Delphi or cardone. I usually like ngk but it looks different so not going with that
  13. P

    Misfires on one bank

    Can’t see tank pressure voltage on scanner or anything similar. Steady felt misfires still on cylinder 4 and now 3 only at idle and no CEL. Got curious today and unplugged MAF and restarted the truck and there was no misfires at all. Could it be as simple as the MAF which I’ve been hesitant to...
  14. P

    Misfires on one bank

    Yea sorry
  15. P

    Misfires on one bank

    The stft for both is around 0. The ltft around -18%. O2 sensors are new and genuine gm with all reading good voltages. As to oil I did just do a change about 600 miles ago. Not sure about tank pressure voltage but will hook up scanner when I’m home and check. The Fuel Cell Trim isn’t the ltft or...
See more

Forum statistics

Threads
138,035
Posts
1,997,551
Members
102,973
Latest member
CRN_25

Latest posts

Back
Top