blaiscaz

Hi all,
I own a 1985 Mercury Marquis Brougham with a 232cu V6 w/87K miles. Ever since October, I've had problems with my car's idle. It began with a high idle when the car was in park. (keep in mind I have no tac) I solved the problem by replacing the idle control motor that is located on the driver side of the TB. A new idle problem appeared and has been a problem ever since, the car basically has no cold start. On a cold day the car will sometimes not fire or if it does fire, the idle is low and sounds unhealthy. I can get it to fire sucessfully if I hold the gas down a little bit, but once I am off the gas it goes back to an unhealthy LOW idle. And quite often, the idle problem varies. For example, the car would start rough as mentioned above, but once driven to my destination, the idle was very high in park. I've fixed that problem today with replacing the MAP sensor. But still, it comes down to NO ENRICHMENT in the cold and then LOW idle when cold. I've never had the car stall out. Once it is warm, however, the car runs fine. Here is the following work I have done to the car myself to help narrow down the problem:
new coolant temp sensor (there are one or two more I did not replace)
new air charge temp sensor
MAP sensor
idle control motor
spark plugs + wires
new head gaskets + upper engine gasket replacement (Cylinder #6 leaked)
new water pump
new ignition coil
TB cleaned
fuel pump on frame and filter are new+ one in tank a few years old
new front suspension (springs + struts)
I know the car has a EEC-IV computer. The valvetrain and idle are not adjustable. I'm unsure if the electrical device that is located on the fender below the ignition coil. I thought it was the ignition module, but apparently that is the electrical device on my distrbutor?? And from what I understand, it could be the ignition module since it counts the cranks rotations and sends them to the computer? If you have any opinions, please let me know. Thank you!!

Sterling_Six

I had a small 1986 Ford escort that was doing the same thing...an finial I had to change the Ignition module on the distributor. it drove me crazy...did you replace it??

__________________
Good Luck and good repairing Sterling_6
"You know, just like in that Book, When Jesus beats up Moses to get Religion!!"

blaiscaz

That was the next thing I was looking at but I couldn't decide to change it after all the failures I had replacing other sensors. It makes sense that it could be it though since it does do the retard and advance on the spark, from what I understand. I suppose it's worth a shot since it work for your car same decade car. Did you have any codes?

blaiscaz

Just pulled a 31 with a code scanner I bought. Looks like something with the EGR. Is there a list of voltages I can go off of to make sure the position sensor is correct?

EDIT: How am I suppose to measure the voltage of the sensor when it is connected to the car?

http://www.my5oh.com/forum/viewtopic.php?t=1326