Ford Bronco 1991 Running Rich

Tiny
FMCCLIMANS
  • MEMBER
  • 1991 FORD BRONCO
I have a Bronco (Full Size) 1991 with about 200k miles.

Symptom: Lopes at idle when engine is warm, runs really rich. In the AM, it starts fine, and takes about 2-5 mintues to develop symptoms (at that point, engine light comes on and off - yes, the problem is slightly intermittent). During the day, however, it takes some foot on the gas to start this beast and the problem starts almost immediately (likely due to it being warmer).

Fixes to date: Had engine codes for bad EGR Sensor and EGO (which only kicks in when warm) - replaced both. Engine codes fixed, problem still exists.

Present Engine Codes: Tested last night - getting 42 and 65.

I'm not sure if there is a bad wire causing the EGO (O2 sensor on exhaust) to not read anything (might be the case IF the EGO High state is Open) or if there is a problem elsewhere (idle sensor, etc.).

Otherwise, the engine is in decent shape. Leaks some oil and TF, but that is about all. The loping has gotten so bad that it occasionally stalls.

Any help would be appreciated (before I tear this whole thing apart).

F
Tuesday, January 23rd, 2007 AT 9:53 AM

2 Replies

Tiny
CUCAMONGAN
  • MEMBER
  • 7 POSTS
I would suspect the TPS (throttle Position Sensor) or the IAC (Idle Air Control) to be your culprit. You can go to Fullsizebronco. Com and search there and they will tell you everything you need to know.

Hope this helps
Was this
answer
helpful?
Yes
No
Sunday, February 18th, 2007 AT 2:00 PM
Tiny
BIGCHIEF31TM
  • MEMBER
  • 6 POSTS
Hello, I dont know if it will be any help but take a look at my issue under 1996 bronco 5.8 reference the egr situation. You might be shocked. Good luck
Was this
answer
helpful?
Yes
No
Friday, May 11th, 2007 AT 3:29 PM

Please login or register to post a reply.

Sponsored links