We have recently installed a 1997 Mark VIII engine into our Ford F150 pickup. The engine turns over and attempts to start but with no luck. What could be the possible problems? What are the solutions? Your feedback is greatly appreciated since this is so frustrating.

 

You swapped the ECM right?

 

The PATS module may be to blame here. I'm guessing the '97 Mark VIII had the PATS I, where it would allow the vehicle to start, but without the right key, it would die shortly after.

I'd see if there was some way to stick the programmer, zero out the PATS and disable it, or perhaps get it able to use a properly chipped key, then extract the transponder out of the key and epoxy it to the reader, so any key would work from there on out.