my 91 automatic stang is idling really roughly. in a driving gear it will idle at 1000rpms, but then suddenly drop to 700-800 rpms for a slight second and the lights will dim and the car will shake like it wants to shut off, then the rpms will go back up, but this doesnt happen in nuetral. anyone know any ideas as to what the problem is???/
idle problems
- Thread starter 91_4ourBanger
- Start date
i4power
Founding Member
Do the major tune-ups first, then check out your transmission. The A4LD automatic is a big steaming chunk of crap, and could be failing.
Jquintel
Member
I'll second that... my 93 used to idle rough, did a tune up, idles fine now91_4ourBanger said:i think it might be my spark plugs, but id like a 2nd 3rd and 4th opinions
to correctly set idle:
unhook positive battery terminal for at least 30 minutes
unplug IAC solenoid
turn idle set screw a couple times to raise idle
put positive battery back on
start car
turn idle set screw down until idle is at about 800 rpms
turn off car
set TPS sensor to .98 volts
plug in IAC solenoid
start car
turn on all accessories and drive for a while
this sets your base idle, and then the IAC can open to keep the car from stalling when accessories slow idle down... sometimes you can make a small change to the idle and then the IAC has to do more work than its supposed to, resulting in a stumbling idle.
unhook positive battery terminal for at least 30 minutes
unplug IAC solenoid
turn idle set screw a couple times to raise idle
put positive battery back on
start car
turn idle set screw down until idle is at about 800 rpms
turn off car
set TPS sensor to .98 volts
plug in IAC solenoid
start car
turn on all accessories and drive for a while
this sets your base idle, and then the IAC can open to keep the car from stalling when accessories slow idle down... sometimes you can make a small change to the idle and then the IAC has to do more work than its supposed to, resulting in a stumbling idle.
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