Questions and Answers
Fast Idle Speed Problem
Q. Hi Vincent, Hope you can help me. I just installed the thermostat (took it out over the summer due to cooling problems now has new radiator and heater core) and after using the car of approximately 20 miles and restarting it I am now getting a fast idle speed.
First so bad I have to hold the brakes at a stop light. I have already sprayed the air intake with gunk out carb cleaner but no change. I also checked the intake? Thought and the circular swiveling thing (that controls air volume/flow) moves back and forth and seems to swing all the way closed.
I took it to a mechanic and he knocked on the sensors around the intake area (its fuel injected but still has the device that controls air flow what ever that's called.
He told me that the automatic choke is stuck and not returning back all the way due to carbon build up. He wants to remove it and clean it and put it back on. I thought that only carburetors have automatic chokes and not fuel injected cars. He wants $275.00 to do this NYC area.
I am stumped. Could this be due to a REVERSED thermostat?
This came on really sudden , I parked , shut of the engine and restarted it 20 minutes later and it hesitated and turned ror a while before starting and ever since has been running way to fast.
1989 Ford Taurus Wagon GL
79,000 miles
3.8 liter Six Cylinder
Fuel Injected
Automatic
No ABS
P/S P/W cruise control
Rack and pinion steeringThanks,
SamyA. It's possible a thermostat that is installed backwards could cause this problem. It's easy enough to check just by looking at it. The large end with the spring should be facing the block. If it is in right, then the mechanic is probably right and the Idle Air Control Valve (IACV) needs to be cleaned or replaced.
Fuel injected cars still have a choke of sorts, although they do not look like the choke on a carburetor. The theory is the same, increasing the idle speed during warm up. It's just done electronically and not manually.
Additional Information provided courtesy of ALLDATA
