Contour Enthusiasts Group Archives Forums General Troubleshooting Won't Idle

Hey All,

Hope you can help.

The car: 1995 Contour SE V6 Duratech ATX, 70,000 miles.

The problem: It won't idle very well. Specifically, my car normally idles around 750. When it acts up it feels like it surges but RPMs actually drop and the car would stall if I didn't step on the gas. I noticed today that when it does it all my lights etc dim when the RPMs drop. Shutting everything off (ie reducing the electrical load) made no difference.

If I stay on the throttle and keep it running (with my foot on the brake or in neutral) then it really misses until the RPMs get above 1500 and even then it doesn't run 100%.

This was an intermittent problem I had last time it got really cold but today it acted up at every stop light and even when I was going slow trying to park. The problem actually seemed to get worse as the car warmed up.

The car cranks over fine but did take 2 tries to start it this morning (stalled first time). Even so, I am thinking it may be the battery or charging system. I'll be testing them when I get out of work later but wanted to see if anyone else had any other advice while I had internet access.

Other info: In the last 5,000 miles I have changed the coil pack, plug wires, spark plugs (motorcraft single plats), air filter, fuel filter, IMRC solenoid and PVC valve. I have also cleaned the MAF sensor, tested the fuel pressure, and torqueed the UIM bolts to the high end of the specs.

I am thinking battery is my next step. Any reccomendations on brand or other ideas about what might be wrong would be greatly appreciated.

Kyle

Replace the idle air control valve (IAC) or see if you have a large vacuum leak.

The IAC is responsible for maintaining idle speed and dashpot control.

Cleaning it sometimes helps. If not, replace it.

As your idles speed drops below the normal minimum, alternator output also drops off. That is what is causing the lights to dim.

Steve

Hey Guys,

Thanks for the advice. Turns out I didn't need it. The car ran just as badly going home on Saturday. It even stalled as I was backing into the parking spot. Started right back up and I finished parking. Shut her off, popped the hood and checked the battery voltage and it was fine (13-14V).

Decided to start her up and see if I could find anything. Started right up and idled beautifully!!! No more problem. I drove it around the block and let it idle for 10 mins and never hesitated, stalled or anything!!! In fact the car has been driving better than it has in a while but not sure why. I tried a "wiggle" test on wires and hoses but never got it to act up so I am stumped. I guess the extreme cold we have been having lately may have been part of it but it wasn't too bad on Saturday so not sure why that was the day it acted up.

Also when I checked I had no codes (No CEL so didn't expect to).

I'll keep all of your suggestions on file so that once it warms up a bit I can really give this car the once over. As soon as I can get the motorcycle out I am going to do the intake manifold rebuild and clean all the other bits (EGR, Throttle body, etc). Will also let me check out all the hoses etc a little easier.

For the record I haven't changed the the O2 sensors. Everything I read here says to rule out everything else before doing that. I am thinking I most definitely have a vaccuum leak of some sort and so as I said I'll be rebuilding the intake when I get the chance.

Again, thanks for the advice.

Kyle

Had the same problem on mine. It came and went, then it came back. Turned out to be the upper intake gasket.

Hey Al,

Thanks for the info. I have been thinking for a while that is my problem and everyone here seems to concur. Glad to have a "real world experience" that indicates it can come and go.

Just curious as to why it would come and go. I could see if it had a leak until it warmed up and things expanded. Or had a leak once things warmed up and loosened a bit, but to do it on odd days and not even (for example) seems weird to me. Guess I'll just have to start taking off every other Tuesday except when there is a full moon

Thanks for the info/experience, I really appreciate it.

Kyle

Sorry to take so long to post. I haven't been watching the group lately. The problem seemed to be highest when it was cold outside. This occured in December and we had a cold snap. I went through the same testing everyone else did. The vehicle was difficult to drive but managable until I replaced the air bypass valve. I was 2 hours from home and struggled to make it back. Stopped at the Auto parts store and in the parking lot toss in a new set of plugs and fuel filter. I was taking pot shots! Made it home and said screw it. Took it to the dealer since I felt it was the upper intake gasket and I did not have the desire to swap it when it was -10f outside. The dealer tested and confirmed it was the gasket. It was deteriated pretty bad. I believe the reason why the problem got worst after the air bypass valve swap was the fact that I layed across the upper intake. I weigh 200lbs and I think it was just enough to move the gasket or open a larger hole to cause the vehicle to run worse(larger vacuum leak). In case any one was thinking I should have swapped out the air bypass valve again when it got worse, I did. That's why I thought the upper intake.