Engine Performance problem
1990 Eagle Talon 4 cyl Four Wheel Drive Manual 101000 miles
Maybe unrelated but this " problem" started right after I left my lights on and drained the battery. I " jumped" the car and it started right away; battery charge came up quickly and has been fine since (3 weeks ago).
I am the original owner. The " hot" idle speed has always been around 650-700rpm until I drained the battery. It is now 1000-1100rpm but only gets there a few seconds after coming to a complete stop. If I take it out of gear, at any highway speed (5mph to 75mph), the rpm drops to about 1400rpm and stays there until I stop the car.
Having been an auto & aircraft mechanic (many years ago) I thought I would just adjust the mechanical idle screw to a lower idle rpm. That's when I discovered this engine has no mechanical idle adjustment (computers!).
So, what's your suggestion for getting the idle speed back to " normal"?
Hi MILTONIAN, Welcome to 2carpros and TY for the donation
Inspect and test the idle air control motor and the throttle position sensor.
June, 12, 2010 AT 1:55 PM
The idle air control motor targets the idle speed as program, a problem with the TPS will also cuase it to flucuate too. Check for vacuum leaks and coolant temperature sensor locked in open loop mode giving fuel when not needed, Remember when the computer loses the correct voltage to operate it loses its program memories and has to relearn itself, maybe this is what's happening now-