damarble
Well-Known Member
- Joined
- June 20, 2008
- Messages
- 759
- Reaction score
- 56
- City, State
- Washington
- Year, Model & Trim Level
- 21 Bronco & 88 Bronco II
Need some ideas! 91 Ex with 285k. Mostly original, the prevous (and only) owner said almost nothing has been replaced.
For a while now it's had a rough idle, I cleaned the MAF then replaced it and no help. Now it's gotten so bad it will sometimes die while idling and the truck shakes violently. Also it doesn't want to rev past 3500 rpm and shudders badly if you try to accellerate while cruising.
My first thought is a blocked cat. The entire area around it is extremely hot. I am picking up a vacuum gauge to test it today. The CEL hasn't come on either.
Need this fixed, it's my girls truck and she's got my SHO until I fix it!
Quick thread recap of tests:
pulled computer codes, KOEO passed, CM 45, 96
cat = removed, no difference, reinstalled
TPS = 0.89-4.63, within voltage range
MAF = cleaned, within voltage range
fuel filter = replaced, resulted in RPM increase from 3500 to 4400
fuel pump and FPR = assumed good, fuel pressure at 32psi at idle, (30-45 acceptable range)
plugs = not replaced but in great shape
coil/wires = replaced, will rev to redline now but not much power
have not checked = compression (no tester that fits), fuel pressure under load, ACT sensor (where?)
For a while now it's had a rough idle, I cleaned the MAF then replaced it and no help. Now it's gotten so bad it will sometimes die while idling and the truck shakes violently. Also it doesn't want to rev past 3500 rpm and shudders badly if you try to accellerate while cruising.
My first thought is a blocked cat. The entire area around it is extremely hot. I am picking up a vacuum gauge to test it today. The CEL hasn't come on either.
Need this fixed, it's my girls truck and she's got my SHO until I fix it!
Quick thread recap of tests:
pulled computer codes, KOEO passed, CM 45, 96
cat = removed, no difference, reinstalled
TPS = 0.89-4.63, within voltage range
MAF = cleaned, within voltage range
fuel filter = replaced, resulted in RPM increase from 3500 to 4400
fuel pump and FPR = assumed good, fuel pressure at 32psi at idle, (30-45 acceptable range)
plugs = not replaced but in great shape
coil/wires = replaced, will rev to redline now but not much power
have not checked = compression (no tester that fits), fuel pressure under load, ACT sensor (where?)