I came across a post on some other forum where a guy said he put one of those split shot lead fishing weights on his throttle cable, so it lifted the cable out of the cam groove enough to increase the idle.
I haven't gone that far yet, but he said it smoothed things out a good bit.
I hate to say it, but quality didn't seem to be job 1 when Ford came up with these cars.
I have a 96 Aerostar that has been hands-down one of the best vehicles I have ever owned.
The Contour runs really well when it runs, for a 4 banger, but I have yet to figure out how to get it fixed, and this seems to be a very common problem with these cars. This is THE worst car I have ever tried to troubleshoot.
I have no problem with Fords, but this does NOT seem to be one of Ford's better ideas.
But, I'll keep plugging, since I actually do kinda like the car.
