Truck cutting off

I have two vehicles that cut off as soon as the engine fires up,(I’m talking spit seconds here, as soon as it hits, it cuts off) what is the problem. Fuel delivery problem, coil pack, mass air flow sensor? One is a 1997 Lincoln Mark 7 I think and the other is a 2003 Chevy 4x4 extra cab silverado and it has an auto start on it, which I can’t finger for the problem being the Lincoln act the same way. The dealer wants to blame the autostart and security system. Very frustrating, PLEASE HELP. Thanks much and God Bless.

You’re describing an ignition module failure.

Ignition modules function in two modes. These are the START and RUN modes.

When starting the engine, the ignition module is in the START mode. It allows full battery voltage to the secondary ignition system to ensure a cold engine starts. Once the engine starts, and the ignition switch moves to the run position, the ignition module goes into the RUN mode. The ignition module then steps the voltage down to the secondary ignition system so these components last longer.

So it could be that the ignition modules are functioning in the START modes, but failing in the RUN modes.


Thank you very much for the reply. I was wondering if you could tell me where the ignition modules are typically located and is there a way they can be tested to see if that is the problem? Also I am guessing these things are not very cheap, do you know?