I finally traced down the hissing sound hear my throttle body/ y-pipe.
Turns out it is the brake booster line that had a big cut in it? It's the 6 inch brake booster hose behind the y-pipe, I replaced with a new one.
My idle use to be 1500rpm fully warmed up. How it's at 850-900 rpm.
That's great but I noticed now when I drive the car and I push the clutch in. The rpm will drop so low that it kills the engine. I have to start the car back up and when I drive and let the clutch out it will drop again and sometimes it will go back up to 850-900 rpm but most the time it will stall and die.
I went ahead and disconnected the battery so and hopefully it's resets the ECU, that way the computer car re-learn with the vacuum leak fixed.
If that doesn't work, I'll have to raise the idle with the BISS screw.. What does everyone else think?
Update: I connected the battery and resetting the ECU didn't fix the problem. My idle is 1100, it doesn't die as much when pushing in the clutch but the rpms will drop to 100-200 and want to die before going back up to 1000 or so.
Not sure what the problem is. It's sounding like the IAC is dirty or something.
Can I use WD-40 to clean the IAC? Also do I have to separate the 2 halves to clean it or can I just clean the pintle?
Well I went ahead and bought a brand new IAC the new style, as mine was the old style(gold color). I'll see if it fixes the problem.
I checked the Dashpot and found the vacuum hose that should lead to the Dashpot check valve(black box) the little black box is missing on my car but I heard it isn't connected to any vacuum or pressure lines.
The Dashpot does seem a little weak as the rubber boot only depresses a little bit. I'm not sure if that is the problem.
I'm not sure if the Dashpot is the problem and I'm betting on the IAC being the culprit, as when I fixed that vacuum leak it was causing the idle problems.
1991 3000gt Vr4. Sold
1992 3000gt Vr4 Daily Driver
Last edited by ThatOneVr4; 11-18-2012 at 02:26 AM.
My car did the exact same thing I haven't fixed it yet cause I just spun a bearing. But I was told it could be two things the iac motor is weak. And are you running a open atmosphere bov try putting stock or a recirculating one in I will be doing this with y car once I get my new motor. I bought a brand new tb off of dbest well not brand new refurbished and I'm sticking a new iac in it so hopefully my car will run smooth and idle great again.
Sounds like no check valve in the brake booster line...
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1991 Dodge Stealth ES - The car that started the 3S obsession
Mods: Open air filter, "resonator" bottle removed
1991 Fiji/Mystic Blue R/T TT 1 of 235(paint/R/T TT only, can't find more info, VIN is a 1 of none number)
Sold 6/19/11 to my923ksl
1992 silver VR-4 - 1 of 152 identical
Show: 99 Sails, 99 rear garnish, 2nd-gen steering wheel, Kaze exhaust cover, Pioneer Premier h/u, aftermarket speakers(Alpine type s's I think), 10 inch JL W1 sub in spnallb corner box.
Go: 15G Turbos, FMIC, ATR DP, ACT clutch, 3-inch singleshot(Currently off car due to bottoming out), no cats, HKS SSQV BOV, PWR rad, Ksport coilovers, 3sx rear adj. control arms, fECU w/ FPR solenoid as BCS, Cianci gauge pod w/ Defi D-series(Boost, EGT, oil pres), 93 shifter. 1987 Dodge Ramcharger - The back-up plan. Mods: Non-computerized timing, custom white gauge faces and red LED illumination, cat-back straight pipe, Chevy seats, Ford running boards, and Mopar everything else.
Wife's ride: 2014 Hyundai Sonata 2.0T --still waiting for permission to mod.
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