another "no idle" ?.....sorry lol

thunderkid84

Registered User
i've been searching thru past threads and cant find my specific problem. i've got an 89 SC 143k and it was idling high at around 2500 and made the goose honk sound when ther car was shut off. from what past threads have said, the IAC went bad. so i put a new one on and now the high idle is gone but it cant keep a normal idle.

i put a timing light to it and everything is getting spark. i swapped with my buddies good coil pack for the hell of it and it made no difference. so i pulled a plug out(no. 2 cylinder i believe) and the thing was gapped to almost .070 and looked a bit old. would bad spark plugs cuz it to not idle at all ?

im thinking its either the plugs are bad or the DIS is f***ing up.

any ideas would be great, cuz im out of them. much thanks in advance.

Jason
 
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check the throtte position sensor voltage it should be .92-.94 volts closed i believe someone correct me if im wrong
and some where near 5 volts open throttle check it with the key on engine off
 
possible boost leak ???

forgot to mention ...while driving it boosts like normal but at about 8-10 psi i hear a very high pitched whine, like higher pitched than a normal m90 whine.

i was searching thru threads and some ppl found that the lower IC tube was not fully sealed causing a boost leak and a rough idle.

possibly a boost leak somewhere ??

i will check the TPS voltage tomorrow, two tone. thanks
 
bump......

anybody have any thoughts ? im very desperate here ! it needs to make a 600 mile trip to SC in about 4 days. im worried !!! HELP !
 
Yes a small vacuum leak will cause it to run like crap, even when showing good vacuum on the gauge.

Easist way to check for leaks is to spray all connections with carb cleaner while the motor is running. Bottom side of upper IC tube connection at the intercooler is where mine leaked most often. Spray all the vacuum hoses too.

David
 
the honk sounds like it could be a IAC i had mine go out and it would die and honk when i shut it off and idle about 2000 it was a PITA so i changed it out in about 10 mins and that was that
good luck
cody
 
I went through, as well as others the gambit of replace this or replace that. Most of the time it is simply a vacuum leak like david said. I disagree with the car cleaner or using propane to check around fitttings. I tried it when I had a leak. I even in frustration had a Ford dealer check and they found nothing. The system needs to checked with pressure. When I pressured my system up I found leaks everywhere.

Ken
 
haha...pain in the a$$...i should've known. i checked for vacuum leaks and done everything short of pressurizing the system. i'll check the most notorious places today, after i check voltage on the TPS and run a code reader on it.
 
for the IAC ....do i absolutely need a ford genuine part as a replacement. the one i replaced it with was from advanced auto. same thing with the TPS if its bad ?
 
i checked the throttle position sensor voltage and i was gettin like .54 volts at closed throttle. does this mean its bad ?

i disconnected the battery and swapped in a new IAC, reconnected the batt and drove for about 15-20mins to let it re-learn. it got rid of the fluctuating idle and goose honk but....

now when i put the clutch in, RPS's will kick up to 2000-2200 and then veeeery slowly drop down to about 900-1000. this happens every time the clutch is in.

anybody know whats goin wrong here ???
 
you need to start it up and disconnect the IAC and let it relearn the idle let it idle for a few minutes 5-10 then when the idle comes back down to normal600-800 some say 550 is normal but it depends on your car then plug back in the iac and let it idle for another 5 mins and then you can drive it and see what happens it worked on my 95 but i can't say for your car
good luck
cody
 
ok i'll try that.

any other suggestions anybody ???

does the voltage reading i got from the TPS mean its bad ?? the only thing it does is idle high at first and then come down to normal, so its gotta be a sensor
 
Idle Problems

My 89 was doing the same thing. I replaced the PCV valve and it stopped. I tried all the other stuff first also. Could have been a fluke but it's a cheap shot in the dark.
 
ok tried disconnecting the IAC while its idling and the engine died. which i think its supposed to do. the car idled for a good ten minutes and gave me some time to check some stuff. i unplugged the TPS and the car kept its idle. is it supposed to do that ? its got a bit of a pulse at idle but i think its cuz my spark are gapped at like .068, way bigger than normal.

what do u guys think ? maybe need a new TPS ?

oh and the PCV connections look good, i didnt take them out and look at them tho.
 
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