Having problems with your 1989 Ford Mustang ?
Hi, i have a 2.3 l 1990 mustang it failed smog cause of instability. it at 2000 rpm it will raise and fall it wont stabilize. i cleaned the i.a.c throttle position sensor. egr throttle body map sensor. compression hot #1 160 #2 165 #3 150 #4 160 so compression is all good. o2 sensor also is good. so im at a loss has a complete tune up. timing set at 10 btdc help me plz.
Did you check fuel pressure? New fuel filter? Clean Air Filter? Do you have vacuum leaks? Sounds like a vacuum leak because the IAC won't hold the idle steady ,because it is being told not to. Have to find out why. Also how did you do the compression test. Remember #3 is lower than the others. Why? Put a professional scanner on the TPS and also look at the spark with an oscilloscope
Repair Help & Product Troubleshooting for 1989 Ford Mustang
Tips for a great answer:- Provide details, support with references or personal experience .
- If you need clarification, ask it in the comment box .
- It's 100% free, no registration required.