Q: the car starts and idols fine but as soon as you press on the accelerator pedal after 10 mph the car stalls. after 5 minutes the car starts again.the car is an 89 mercury grand marquis and all ignition parts are new except the coil.
A: new ignition parts: did that include the ignition module?... IF you did change the ignition module... did you replace it with an original FORD part, or a cheap aftermarket module? Do you still have the original module?? try plugging that back in. If you didn't change the module, try a new one, but make sure you get a genuine Ford/Motorcraft module, because the aftermarket ones DON'T WORK!!! A way to test if it is the ignition module: start the car, put it in Drive, then hold the key to the Start position (don't worry, the starter won't engage when the car is in Drive)... this will put the ignition module in Start mode, utilizing a different circuit (which appears to be working because the car starts), and see if the problems go away. If so, it's definately the ignition module.