Way high idle, still dont know what to do

[goatman]

Hey, its been a while since I've been around, wow, the site looks awesome. Good work. Heres my problem, After the first time the engine came out, everything went back together and worked just fine, better than it had before. Unfortunatley, 55 miles later, the trans went out. Ok, pull everything apart again, get the trans fixed, put it all back together. Start it up, it shoots straight up to 2700 rpm. All vacuum lines, all sensors, everything is all in order, I've checked it I dont know how many times. Heres the thing tho, the axles are still not in the car, I know, its been almost a year now. Its still up on the jack stands, so while its running, Ill shift it ino neutral, and the speedo will jump up to about 60, and the trans is turning. WTF? Busy season is over now so I went up and worked on it today, just wondering if the shift cable was in the wrong position and if this may have something to do with it. nope, everything checked out, jumped it, started it up again, same thing. I am just completely and utterly lost. If anyone has any ideas or suggestions, I would greatly appreciate it, cuz otherwise its going to a $4000 push-pull-drag sale. Thanks in advance

[RollinonZ34]

High Idle

High Idle sounds like the Intake Maniflod Gasket, or as mine turned out to be...the Lower Intake Manifold Gasket. Just wondering if you changed this the first time the engine came out? As far as the Tranny...????? Got me!

[gpse3400]

You may have a vacuum leak. I'd be spraying down the top of the engine with carb cleaner while its running. Try spraying the EGR valve. Also check the Brak booster vacuum hose. Otherwise the Idle air control motor might be stuck. As for the transmission, there is nothing wrong. When the car is up in the air and in neutral, engine running, the wheels will turn foward, that is because with out getting too in depth, certain things are applied in neutral that will cause that. Rest assured, when you drop the car down it will act like it is in neutral with only an uneven surface to cause movment of the vehicle.

[grandprixgtp_91]

you could have a plugged iac , if it gets alot of dirt and carbon on it it will stick open, ive had that before, and also you shouldnt run an engine with an auto tranny without the axles out of it.

Jake

[Kyles93Z34]

High Idle sounds like the Intake Maniflod Gasket, or as mine turned out to be...the Lower Intake Manifold Gasket. Just wondering if you changed this the first time the engine came out? As far as the Tranny...????? Got me!

Exact same thing happened to my old 93 Z34. Same probelm, same solution.

[n0rt0npr0]

Hey guys, I'm having the same high idle issue, but I sprayed the shit outta the top of the motor, with no change in vaccum (vac gauge says 20lbs) and no change in RPM (least from what I can hear)

Whats the best way to go about diagnosing a bad IAC? I've cleaned mine spotless, and reset it numerous times (turn key on for 5 seconds then turn off at least for ten and the pintle will fully extend out)

[goatman]

Yea, I've reset the IAC several times, the intake gaskets are good, (I've replaced em twice) sprayed the whole thing with carb cleaner and saw no vacuum leaks. Thats why I'm so lost on this thing. But its not my prob anymore, I sold the car the other day, and bought a 1990 GMC Sonoma. Not a 60v6, but at least its GM

[MMGT1]

Does that reset(5 sec on then off for ten) work on all applications? Mines a 2000 GAGT with the 3400.

[n0rt0npr0]

You can find out for yourself on that IAC...take it off, tie a baggy around it, then proceed with the IAC reset. instantly you will know if it worked when you peek at the motor.