idle question

tbird79

Registered User
The last couple days the idle in my 90 sc has been acting up, when i come to a stop somtimes the idle will drop below 500 but wont stall, and then goes back to a normal idle (a little rough but not bad). And one other thing I noticed was when driving...just say around 2000 rpm it almost feels like it misses every now and again, nothing violent feeling, but I can notice it. Any advice would be great. I think I will check codes....good place to start i guess.

Thanks
Joe
 
How are your engine mounts? Also, any vibration coming through the frame when you're sitting at a stop in gear?
 
idle

Ill check the mounts as soon as I can, I dont feel any vibrations really but i will definatly check the engine mounts.

Thanks
 
Idle falling off...

Mine is doing the exact same thing right now. Check out this post and see if your car is doing similar things as mine. Mine ended up being the O2 sensors.

Idle

It may not be the only problem, but it is a start. I'll be fixing mine as soon as I get the $$ for the O2 sensors. They like to show they are going bad when it starts to get cold out. If it is your engine mounts, put your car in gear (reverse) with the emergency brake on. While in front of your car open the throttle up a little. If the engine moves--I'd say more than 1/2 inch--you need new mounts. If you have a 5 speed, you will obviously need someone's help with this.
 
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P.S. You will more than likely get a code of alway lean (Left, Right or Both) side(s). And the 'missing' is probably detonation. Try finding a gas station that has 92 octane--that fixed that for my car.
 
p.s. You will more than likely get a code of alway lean (left, right or both) side(s). And the 'missing' is probably detonation. Try finding a gas station that has 92 octane--that fixed that for my car.

so did the o2 sensors fix for the long term or did it just cover up something that poped up later?
 
so did the o2 sensors fix for the long term or did it just cover up something that poped up later?

Holy resurrection!:eek: I can't tell you for sure. The SC I had then is LONG gone...parted and crushed, I'm sure! This thread goes back over 7 years ago. I remember having some issues with that SC, but with the purchase of the one I have now and the rust that was on that one...it got parted. I don't even remember if I ever got the issue resolved or not.
 
so did the o2 sensors fix for the long term or did it just cover up something that poped up later?

had the same thing happening to my bird, once i got the QH installed i seen off the bat that my o2's had gone out. i replaced them and the car hasnt done the idle dip since.
 
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