'91 302 running issues
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Senior User
Joined: Dec 2015
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'91 302 running issues
hello..... ive changed the TPSensor ..IAC valve...MAP sensor...engine temp sensor...checked the fuel pressure and it still wont run right. exhaust smells funny...not a rich smell. it will idle fast all the time...1000 in gear. 1200 to 2500 in park.
new plugs..wires cap and button 2 years ago. 115K mikes. any ideas?
new plugs..wires cap and button 2 years ago. 115K mikes. any ideas?
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
Start the motor and let it run a few minutes.
Then remove the electrical connector from the IAC valve.
If the motor slows down to about base idle 500 rpm or so, the IAC is being electrically held open for some reason.
Also check the throttle bore and plate for build up and spray clean if needed until it is clean.
Other checks to make is ignition timing using a timing light with the timing plug removed. It should be about 10 degrees BTC static.
If none of these clear the issue, look for a large vacuum leak.
Check throttle cable for hanging up.
Then remove the electrical connector from the IAC valve.
If the motor slows down to about base idle 500 rpm or so, the IAC is being electrically held open for some reason.
Also check the throttle bore and plate for build up and spray clean if needed until it is clean.
Other checks to make is ignition timing using a timing light with the timing plug removed. It should be about 10 degrees BTC static.
If none of these clear the issue, look for a large vacuum leak.
Check throttle cable for hanging up.
New User
Joined: Nov 2019
Posts: 1
Likes: 0
Start the motor and let it run a few minutes.
Then remove the electrical connector from the IAC valve.
If the motor slows down to about base idle 500 rpm or so, the IAC is being electrically held open for some reason.
Also check the throttle bore and plate for build up and spray clean if needed until it is clean.
Other checks to make is ignition timing using a timing light with the timing plug removed. It should be about 10 degrees BTC static.
If none of these clear the issue, look for a large vacuum leak.
Check throttle cable for hanging up.
Then remove the electrical connector from the IAC valve.
If the motor slows down to about base idle 500 rpm or so, the IAC is being electrically held open for some reason.
Also check the throttle bore and plate for build up and spray clean if needed until it is clean.
Other checks to make is ignition timing using a timing light with the timing plug removed. It should be about 10 degrees BTC static.
If none of these clear the issue, look for a large vacuum leak.
Check throttle cable for hanging up.
Thank you ill try this. friend of mine says the PCM could be bad but woukdnt that cause other issues as well? tranny not shifting right ETC....
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