Physh1
Full Access Member
- Joined
- Jul 29, 2010
- Posts
- 773
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A few weeks back I popped a ses light & truck started idling bad, missing, but seemed to run fine at higher rpm. Codes were running lean bank 1 with misfires on 3 & 7. Stock 5.3 with 225k & a blackbear tune (75k ago).
I replaced the o2 sensors with delcos (under warranty to cover my bases), new injectors, swaps coils around (no change), swapped plugs around (no change), swapped wires around (no change).
- Used a noid light on all injectors...all are good.
- Oil pressure is good, no coolant in oil, no consumption, no junk in oil...
- Compression test...180 (plus or minus 5) on all 8
- Vacuum is 19-20 at idle constantly...
- Head gaskets are good...no hydrocarbons in the coolant
- Best I can tell I DON'T have castech heads
- I recently (15k ago) did intake gaskets & did the again last week just in case...no change
- fuel pressure is 62psi & the FPR is good as well
- sprayed carb cleaner EVERYWHERE & there was zero change
Weird things...plugs on cylinders 1&2 are reading rich, 3&4 better but still rich, 5&6 are normal, 7&8 are lean. Also, there is a definate change in how the truck runs when cold (open loop) than warm (closed loop).
Ses goes from solid to blinking randomly with no real change in engine sound or misfire counter.
Mechanic I work with is not sure what's going on.
What am I missing & what should I look at next?
Cameron
I replaced the o2 sensors with delcos (under warranty to cover my bases), new injectors, swaps coils around (no change), swapped plugs around (no change), swapped wires around (no change).
- Used a noid light on all injectors...all are good.
- Oil pressure is good, no coolant in oil, no consumption, no junk in oil...
- Compression test...180 (plus or minus 5) on all 8
- Vacuum is 19-20 at idle constantly...
- Head gaskets are good...no hydrocarbons in the coolant
- Best I can tell I DON'T have castech heads
- I recently (15k ago) did intake gaskets & did the again last week just in case...no change
- fuel pressure is 62psi & the FPR is good as well
- sprayed carb cleaner EVERYWHERE & there was zero change
Weird things...plugs on cylinders 1&2 are reading rich, 3&4 better but still rich, 5&6 are normal, 7&8 are lean. Also, there is a definate change in how the truck runs when cold (open loop) than warm (closed loop).
Ses goes from solid to blinking randomly with no real change in engine sound or misfire counter.
Mechanic I work with is not sure what's going on.
What am I missing & what should I look at next?
Cameron
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