[Scotiee45]

Can someone give me idea on why my idle is screwy. I noticed that it started last week after driving the interstate back and forth from work I have a 91 kick 1.6 8v 5 sp. 2 door. Most days it drives fine with the idle @ 800 rpm. Then off and on thruout the week it will idle 1200rpms. I have replaced many parts within the last 2 yrs. EGI, TPS, MAP, Batt, Alt, Timing Belt, Fuel Pump, Fuel Regulator. Ran fine after replacing all these parts.

 

[Bex]

Assuming that the timing is ok, you should check for vacuum leaks, which will raise the idle. Pinch all your vacuum hoses with a pliers. Except for the ISC (hose that comes from the air pipe by the air filter) you should have no change in the idle when the hose is pinched. If you find a change, then you have found a vacuum leak on that circuit. When you pinch the ISC hose, the idle should drop to about 400 rpm or so.
You may also want to check that your throttle cable isn't sticking anywhere.

 

[Scotiee45]

No vacuum leaks. Brand new ISC, and Brand new Throttle Cable.

 

[Bex]

Hmm....well, brand new does not necessarily mean no kinks, or good wiring. To check your ISC, aside from the vacuum test above, have the car idling and turn on the heater blower on high and the headlights. What does the idle do?
And if the car is idling at 1200 rpm, if you rev it, will the idle come down?
Also confirm that your check engine light is on with the key on and off once the car starts, and that your engine is heating up to the proper running temp. To ascertain this, don't just use the temp gauge on the dash (meaningless) but a IR thermometer at the thermostat housing. Should read about 170F. The ECU will idle the car higher if the car is not warmed up properly, or if it's getting a signal that it's not warmed up. The coolant temperature sender (green sensor that is near the thermostat housing) sends this signal to the ECU. When the car is fully warmed up, the resistance across this sensor should be about 350 ohms. If it is higher, it is signalling to the ECU that the car needs to be warmed up further.