Expert: Robert Summers - 11/7/2007

Question
Hi Rob,
The car is a 1991 Corvette Coupe with AT, 5.7L TPI L98, with MAP intake metering and HEI-distributor.

The car has been stalling intermittently for the past couple weeks. It runs perfectly otherwise, with no hesitation, no lack of power, no sputtering, no surging. It doesn't matter whether it is the first start of a cold morning, or if you've been driving it for an hour at operating temperature. Rain or shine, no difference. Sometimes it will go a few days without stalling, other times it may stall 5 times while driving across a parking lot.

The engine completely shuts off, as if someone had just turned off the key. However, the backlit LCD speedometer on the same circuit as the ECM remains lit, which indicates the start/run position of the ignition switch is not at fault. Occasionally, if driving at sufficient speed, the engine will shutoff briefly and then due to the movement of the car, restart on its own.

Also, throttle position has nothing to do with it, as the problem occurs equally at idle, cruising, coasting or accelerating. MAP sensor is operating within spec.

The car always restarts right away, as it did before the problem began. There is no CEL, nor are there any stored codes. I have tried wiggling, and unplugging/plugging all underhood connections that I see. Coil, cap and rotor are all in good shape.

Any suggestions welcome,
Brad.


Answer
Hi Brad....could be a couple problems.. first check the wires that go from the dist to the plug on the cap where they come out of dist housing.. sometimes they will fray and short out. also when you say HEI dist is it the one with coil in the cap. if so check coil... also check module in dist and wires going to it. your problem sounds like it's in the dist and sence you have no codes i wouldn't believe it's computer related. if you have a good spare dist, try it. also check the power lead to the dist for an intermittant open...i hope this helps...