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Discussion Starter · #1 ·
Alright all, yet another problem with my scort...becoming a pain. O well on to the problem, my idle jumps. Lets say it idles at 800 RPM, then all of a sudden it jumps to 1200-1400 RPM. It never did this before. And the Throttle Position Sensor, or whatever it is had been changed like 8000 miles ago. Any suggestions? or even previous experiences, keep in mind i drive my luxurious 1989 LX auto.
 

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Bah ha, I got the same thing :?

New TPS
New ECT sensor

All is well and good electronically.

If it does what mine does, it'll warm up ok, then when its supposed to idle down after warm up, it idles right on 750rpm. Almost like its starving for fuel, rpm's drop, then rev up to compensate. I did a leak test around the manifold with some oil, and it improved (not to normal) the performance of the engine. So I slapped some lithium grease around where I think it's leaking, and it helped pretty good.

Since I drive the car everyday, I had to find time to go to the wreckers to get another manifold. After I removed the over 1/8" of carbon from around all of the walls of the manifold, I painted and polished it. I should finish up the manifold tomorrow, and will have it installed on Sat.

Other possibilities with the manifold than just a vac leak:

Too much carbon in intake manifold restricting flow.

Bad gasket leaks vac. and coolant, or coolant only. The 1.9's (at least in the sec gen) have the intake manifold sealing a couple of water jackets in the head. Not a big coolant leak (can't see white smoke), but enough mist to get it to run bad.

Injectors are blocked by carbon.

Like I said, this weekend I will swap the manifolds. I will see what I find out, and post back. Knowing my car, I'm going with a vac leak and a really carboned up intake. :cry:

Matt 8)
 

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Don't know whats going on on the 1rst gen ,but on the second gen.(94LX) most likely is your IAC valve.Its basicaly an air compensator valve.When they go haywire,one of the problems it gives is the erratic idle.It can also cause stalling when ac is turned on or a hard start condition.Check it out first before pulling apart your intake.
 

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Discussion Starter · #4 ·
well my brother said, he was a mechanic, and he said it could be that my A/C compressor doesnt shutoff. I dont know if thats true, but i belive im gonna be needing a new clutch for my AC. and im ,lucky that im acquiring it from a donor scort.... :)
 

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WANAGOFAST said:
most likely is your IAC valve
Been there, done that. It does it with the original IAC, plus a know working one from the wreckers. And yes, both of them are clean and free of carbon, and the throttle body has been cleaned out.

And just to save some time, I also replaced all of my vacuum lines with new silicone ones, as the old ones looked pretty ratty. Still no change.

Matt 8)
 
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