Hi, I've had the same problems as have about 500 other CEG'ers here with the 2.5l V6. See the threads on IAC, Moosing, MAF, vacuum leaks. I *think* I finally fixed my cold start wandering idle and then dies and idles really rough cold and still a little rough warm and dies at stoplights cold problem. Never got any CEL/Code for this. I have a 97 Contour GL Sport 2.5L engine Auto Trans, 80,500 miles. Had the car since new.
I replaced my IAC valve last winter when this first started happening to me as recommended here many times. Unfortunately, it got warm after I did this so I couldn't test it cold till this winter. Sure enough, the problem was still there the first days below freezing. The IAC change didn't fix my problem. I used an aftermarket IAC--don't think this matters.
Next, I cleaned the MAF. This wasn't it for me. Then I took off the throttle body inlet tube. I sprayed 2 CANS of carb/fuel injector cleaner into the engine while running to really clean out the intake/throttle body. Turns out my secondary throttles in the intake manifold were not opening at all anymore for the last year or so--all gunked up. With this spray fix, they started opening up at higher engine speeds again. Really did wonders. Someone on the thread recommended you do this by removing the two little tubes directly on top of the intake manifold downstream of the throttle body. I don't recommend this. I did it this way first and broke one of the tube ends off. They go deep into the manifold so not easy to do it that way. So with that, the car ran much better WARM and at higher engine speeds but didn't fix the dying/rough idle! I also cleaned out the EGR cast passages between the throttle body and intake manifold as recomended here. Mine were totally clogged with gunk. Be sure to do this if you take off the throttle body. Replace with a new gasket for sure too.
Ok, so what to do next. I had a tuneup a year back (plugs/wires) so that wasn't it. Well, I sprayed the carb cleaner around every hose/tube/connection I could find while the engine is on. This is enough fuel to get sucked into a crack/loose fitting to rev up the engine. That's how you find a leak. Sure enough, the 4" long bent rubber tube that comes off the PCV valve had a 1" long split in it. These get hot and deteriorate over time. Any hose could have problems... This one is not visible unless you feel a split from underneath. The carb cleaner spray can really help to find leaks like this. This PCV valve is in a horrible spot, below and towards the firewall end of the throttle body. I had to remove the throttle linkage bracket/springs/accel cable to get to the PCV area - 3 M8 screws. Well, after replacing hose and PCV, idle quality has improved alot cold and some hot and my cold start dying has stopped. Idle is stable at 500 rpm now cold. Engine runs great. Been this way for a week now for me. Some folks have replaced throttle position sensors and maf (mass air flow) sensors but I didn't. I suspect I didn't need to replace the IAC either. Check all your hoses for leaks first. Clean our your Intake/Throttle next if you have >50,000 miles. Do the Moosing/throttle hang fix with the brass plug with small hole in it described on the thread. (I actually have the Ford alternate tuned resonance tube TSB fix for the Moosing on my 97 but I did the brass plug also anyway.) Hopefully, these things will fix the rough idle/cold start dying problems many of us have.
- Contour_97
Ex Ford Motor Dearborn Design Engineer/Analyst - 7 years
Now Caterpillar Valvetrain Design Engineer - 6 years
97 Contour GL Sport/Auto/2.5L V6/80,500 miles
Love my Contour when it works!
