Ok we just finished swapping a new engine in our 94 camaro 3.4
Now the problem is I wont idle at the right speed
It idles around 2500-3000
Well it will start and stay at around 1200 or so for just a moment then revs up
Sounds like a vacuum leak or something but we checked them...
There is what looks like a vaccum hose on the part of the wiring harness that comes up in the back middle of the engine- where the main injector harness plug is
What in the world is this for? Can't find a place to put it??

Is there a gasket on the intake plenum? because it seems like it could maybe leak in there or something
And does anyone know the specific tightening pattern for it

 

Be sure your air temp sensor is working on the air snorkel, as that could create the high idle condition -- I have seen it on my 3.4 when I had it unplugged driving...

 

If everything is correct, it is gong to take several start & stop cycles for the computer to get the idle at the right speed. Is the service lite lit? If it is scan the PCM & see what the complaint is. Otherwise if the problem continues:
Check IAT sensor, as Liberty said. Cold indication may result in fast idle.
Check ECT sensor. Cold coolant indication may result in fast idle.
Make sure that the throttle cable is connected in the right spot, not binding andkeeping the throttle valve from closing fully.
Check the cruise control cable, same as above.
Make sure no sensors were left out
Check the idle control valve for proper operation. (also take it out & clean it, dirt may be holding it open)
Look for air/vacuum leaks between the throttle valve and heads (Intake manifold gaskets)
Check the PCV valve and hoses for leaks and proper operation (make sure valve is there)

 

Ok don't know how to check that but...
Took off the plenum AGAIN and there is a gasket so I dont know
Any other ideas?

It runs for awhile at a good idle then just slowly speeds up to around 2500-3000rpm

 

Ok didnt see that one before me before
Thanks for all the help