New to the site, did a search couldn't quite find my problem though.
I was leaving work the other day and as I was going down the road, my check engine light popped on and the truck shuddered and lost a lot of power. It's a 91 lariat and I've already replaced the fuel filter and ignition igniter module. If the truck is cranked and running it does fine, but after a while 5 min or so the check engine light will come on and it runs terrible. I can't give it full throttle without it bogging down, it acts like it doesn't shift, like it's stuck in drive, and if it goes dead I have to wait until something cools down before it will start and it's fine again for a few minutes. I had Oreileys do a check engine test and he told me that he can't get a reading because the test point has no power. I'm racking my brain on this please help.

 

It sounds like it is going in safe mode most of the time you have to take it to the dealer. We really need more info for any type of answer like engine size tranny and as much as you can give that would really help us. It could be anything like a loose connection to a broken sensor or something worse. We need some more info