SPONSORED LINKS

Fiero runs really bad

Tiny
ROBERTP3270
  • MEMBER
  • PONTIAC FIERO
My 1987 Pontiac Fiero Coupe w/2.5 tech 4 w/ electronic ignition w/automatic w/ 87,000 on rebuilt motor, just started running really BAD and the check engine light came on and I run the codes and it coded 25; The local dealership says no code for 4 cylinder and it meant I had a bad computer, I have replaced the computer and the throttle position sensor and still it run really BAD and black smokes and stalls. HELP! Rob
SPONSORED LINKS
Tuesday, June 26th, 2007 AT 8:05 PM

1 Reply

Tiny
MMPRINCE3000
  • MECHANIC
  • 133 POSTS
Code 25 (MAT sensor) applies to the V6. Recheck the code.
When a sensor is bad (MAP, TPS, Coolant etc.) The ECM will set a default value. This is always rich to prevent a lean condition and engine damage (although extended rich condition will also cause damage).
Grounding terminals A and B of the ALDL (engine off, ignition on) will cause the SES light to display the code(s).
First it will flash code 12 (3 times, flash. Pause. Flash, flash), then all error codes (3 times). When all error codes have been displayed the SES light will again display code 12.

More than likely you have a bad sensor, see if Autozone, Advance etc. Can scan the computer for you and isolate the problem.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Wednesday, June 27th, 2007 AT 8:02 AM

Please login or register to post a reply.

Related Engine Runs Rough Content

Is it Safe to Drive Check Engine Light?
VIDEO
Is it Safe to Drive Check Engine Light?
Instructional repair video
Check Engine Light
GUIDE
Check Engine Light
Why is my check engine or service engine soon turned on? In this guide we talk about what this is associated with this notorious light, what it is used for and what you...
VIEW MORE

Sponsored links