Carb rebuild, new key, MPEM?????

[Summerfun11]

Brought my 96 GTX to the shop to have the carbs rebuilt this spring. I get a call and the mechanic who says I need a new key. Funny, never had a problem with the key, started fine every time. So I take it to another shop to have a new key reprogrammed. They say the system won't stay energized long enough to get a new key programmed, might be a bad MPEM. I get 2 short beeps when I put the key on the post and the gauges stay on for 30 seconds. I can start it but it but runs rough, backfires, dies. Does this sound like a possible MPEM problem to anyone? Where can I find the test info for the MPEM?

Thanks in advance for any help,
Steve

 

[purple_people_eater]

i'd start with checking the post with a multi-meter, there are threads here about what your looking for. as far as the backfireing/ rough running, do you still have the grey fuel lines? and when where the last time your carbs where rebuild?