Ok my car has been idling pretty low. Like around 600 RPM. I think it used to idle that low on the old motor but now at idle it's at 10hg in vac so it's really rough and dies once in a while. Usually when I have a vac leak and I'm driving and push in the clutch it will linger at ~2000 RPM until I completely stop. NOW it will hold at 1000 RPM but when I come to a dead stop it will idle way down and lose vac. The way it's acting now makes me think it's something other than a vac leak. What would cause that? I'm thinking either IAC or TPS. Any ideas?

Still sounds like a vac leak somewhere, but I wouldn't rule out the IAC. I had a TPS die and it keeps the car revved up to about 2k +.
See if you bum an IAC off somebody to see.

wat about the Manifold Absolute Pressure sensor? i know that measure and regulates pressure. just an idea.
later

Is your car more prone to do it with accessories on?




Jon

1997 Eclipse RS

14.49@99mph 7/27/02

MODS: 8.8:1 JE Pistons / Eagle rods / Stage 1 Hahn turbocharger / Melling Oil Pump / Autometer 5" tach / 2 JL 12" W0 subwoofers / JL Audio 500/1 amp / Clarion 230w amp / short shifter mod / GReddy EVO exhaust / custom 2 1/2" downpipe / no cat con / CM Stage 1 / 30lb Mustang injectors / TurboXS MBC / 1G SMIC

Well I haven't used my AC yet. But it doesn't make a difference w/ like lights and stuff on. I think I'm going to clean the IAC and try it w/out the missing link and see what happens.

I would check the Map sensor too. Get a volt meter and measure accross the map wires, with the car off, and key in the on postion. YOu should get about 4.5 volts or very close (meaning .1 to .3 volts, give or take from 4.5)

I'd look very closely for a vacuum leak. That's usually the most common cause of rough idles.