My 1993 Escort 1.9 five speed is suddenly idling too fast, i mean really fast, even after warm up. I can’t find a vacuum leak and I’m leaning toward the idle control motor, but it’s $60 and I don’t want to just throw money at the car. Another clue I’ve noticed is in the summer, this engine won’t increase RPMs when the A/C is switch “on.” I understand the Idle control motor is supposed to control idle through the ECU with inputs from other sensors. Without a scan tool, I’d hate to throw an idle gizmo at the motor only to find the problem rests with another sensor, or something even simpler. I’m about out of ideas, but I’ll bet I’m not the first to have this problem on an Escort.
thanks, folks, in advance.
Michael
Ok, how about $20 dollars for a Haynes, or Chilton’s, repair manual? One will show you how to determine if a sensor is faulty, or not. The various sensors send signals to the engine computer. The engine computer decides what action to take, and sends a control signal to the component (such as an idle control valve) to perform in a certain way. You could think of a digital voltmeter as your scan tool.
How did you check for vacuum leaks? You can disconnect every vacuum hose, plug the intake side, and listen for engine changes. The hoses to the brake booster and the cruise control are vacuum hoses, too. Pull, plug, and check.
Okay, well, my first stop was the Haynes manual for this car, then the Ford factory repair manual, neither of which provide enough specific information to test most sensors. Without specific electrical values and methods for testing particular components, simple identificaiton and locations isn’t much help, even with my several multimeters. But hey, don’t think I don’t genuninely appreciate the condescending tone of this answer with its implicit belittling. The Escort has precious few vacuum hoses and the radical change in idling speed I’ve experienced suggest a vacuum leak should be audible, at least with a piece of hose in one’s ear. I haven’t had success with this method, or with sarting fluid. And, that brings me back to the idle control motor. I think. But, without specifics about this part, I’m just throwing parts at the car, which gets expensive pretty quickly. Any help that refrains from overflowing with sarcasm is greatly appreciated.
Michael
try auto zone web site they have a trouble check and repair page.
Here’s the really weird thing. I hooked an analog multimeter to the test port and got some really weird codes that didn’t make any sense both with the key on, engine off and with the engine running, but when I cleared the codes, the engine started running great, and has continued to run well all afternoon. I wonder if it’s possible the ECU stored a code that was an anomaly and was reacting to it until the codes were cleared. Now, I’m as confused as ever, but the engine’s running great again, so I’ll just have to keep an eye on it, I suppose.
Michael