If you have an orangish light it's a fault in the engine control.. There should be a trouble code stored.. Since your car is pre obd2 chanced are Autozone can;t scan it, although it does depend on the store... YOu can acutally get the codes out yourself with a jumper wire and analog voltmeter/test light...


Definitely need to run a little heavier oil though!!

 

Your car needs servicing and you should do it immediately.

 

well i do put 10W30 GTX High Milage oil and im starting to get some wired problem. Sometime and i mean SOMETIMES i can't start the car? Wired right but when i put it in Neutral it starts???? WIRED

 

the neutral safety switch may be bad in the park position or the linkage may be a little out of adjustment.

 

Even the previous owner of my car told me that the check engine light was on for a while but nothing ever happens to the car just keep running fine every day but ill get the code for it and let you guys know what it is. And thanks ill get it checked out should be one of the two or both ahahah

 

I have the identical idle problem with my 92 Marquis, but I didn't run through a puddle like 89 Grand Marquis did. It started out fine, but the idle won't stay steady and it sometimes stalls. Yet, once it gets going, it runs and rides like a dream. The car has 82,000 original miles and still looks great! The check engine light occasionally comes on, but goes back off. The owner's manual says that if it goes out, it fixed itself. I doubt that. I gave it a full tune-up(plugs wires, PCV, and fuel and air filters) last week, and tried the reset like Crown Vic suggests, but it didn't fix the problem. What is an IAC? I really don't want to take it in and get screwed by a mechanic. Anymore helpful tips?

 

IAC is the idle air control. it's a motor attached to the throttle body that allows more or less air as needed to control the idle.

 

Slymer,
Thanks for the info. I have since found it at the back of the throttle body and it is buried under a few things. I have priced it around $45, but is there an easy way to test it before I dig it out and replace it? Also, how much impact does the throttle positioning sensor have in this case? It's cheaper and much easier to replace-LOL. I welcome your thoughts.

 

the IAC you probably only need to clean. Carbon deposits tend to clog it up. The TPS can be tested with an ohm meter by disconnecting it to make sure it's ok. I don't remember the checks off the top of my head, but generally there should be about 10K difference between closed and wide open and it should be smooth on the way from one to the other. There should be no sudden jumps.

this site shows using a voltmeter with the sensor still connected (key on engine off): http://fordfuelinjection.com/?p=30

 

Sounds like a plan. One more question before I pull the IAC for cleaning, is there a gasket that I need to replace or does it have a reusable rubber "o" ring? I think I liked it better when cars didn't have all of these fancy electronics that makes my engine smarter than me!