Manifold backfire & hesitation?

[Hossbaby50]

No plug wires crossed. I resealed the manifold, EGR and replaced the IAT sensor tonight. A little better but still the pops and hesitation. Tomorrow I will reset the timing to 0* and then .

Harley

 

[eagle mark]

put a vacuum gauge on and look for a steady reading, any fluctuation indicates a intake valve going bad which will cause the popping in the intake.

 

[Hossbaby50]

vacuum reads 16-18" at idle. My idle hunts around a little and the number fluctuates between 16-18. The idle has hunted for years though, and it is actually idling better then it has in a long time.

Harley

 

[bigblock72]

Sounds like a bad/contaminated MAF causing mixture to go lean. Need to have some datastream to confirm though. If you know someone with a running TPI setup maybe borrow their MAF and see what happens. The rebuilt MAFs are usually questionable at best so plan on going through 3 or 4 to get a good one.

 

[dyeager535]

I *THINK* disconnecting the MAF, if it's bad, should send it into limp mode, which should "cure" the problem if the MAF is it.

 

[Hossbaby50]

I *THINK* disconnecting the MAF, if it's bad, should send it into limp mode, which should "cure" the problem if the MAF is it.

That was my train of thought on the MAF issue. With the MAF disconnected it should reset to factory generic fuel maps and shouldn't run the same.

 

[British Slave]

Oh, for the days of points and condenser!

 

[dyeager535]

Uh, no thanks. I wish my lawn mower was fuel injected!

 

[Jason4x4]

That was my train of thought on the MAF issue. With the MAF disconnected it should reset to factory generic fuel maps and shouldn't run the same.

Unless, the maf is bad, and it is already resetting to generic, and that could be why it doesn't change.

 

[dyeager535]

Can't count on them, but my MAF consistently threw codes when it was "bad". (actually it was a bad connector)

 

[Blazin'4x4]

Any updates? I have the same problem with my tbi....

 

[destro360]

ok im p.o.'d i got the same issues with my tbi... fresh tune, fresh valve job valves adjusted correct timing is good. i hate driving this thing.. it dies at every stop light and backfires everytime i accelerate...