Help!!! High idle after warm!!

[clutch88gt]

I just recently but a newer motor in my 1994 explorer it was running like crap and found out that I had pretty much all the vacuum lines mixed up so I had someone reroute them for me and they got it running pretty good. When the engine is cold it starts and runs great but once it warms up it starts to idle at 3000 rpm's and then if u shut it off and try to restart it has a hard time starting. You have to continually crank it over until it decides to start. In the proses of starting it at this point it has a old gas smell but it has fresh gas. Im thinking its a vacuum line or the IAC (Idle Air Control Valve). Any input will be greatly appreciated.

 

[2000StreetRod]

check throttle plate & TPS

Make sure that your throttle plate returns to the fully closed position (hits the closed stop). Also, previous owner may have adjusted the throttle stop screw keeping the plate partially open. The plate should close almost all the way but not so much that it sticks when you open it. There should me a little slack in the trottle cable when the accelerator is released.

The TPS output voltage should be approximately 1.0 volts when the throttle plate is closed.

Make sure there is a gasket under the IAC valve.

 

[YBCold]

im not sure if this is a factor but sometimes your engine coolant temperature sensor goes bad and it causes engine starting troubles its located up near where the upper radiator hose connects to the thermostat i think it has a gray wire plug. dont confuse it with the one that goes to instrument cluster. this one goes to the PCM.

also check your intake manifold gasket. airfilter, fuel filter. and maybe your EGR system. i think 94s have EGRs