Okay first I want to apologise if this is in the wrong spot. I'm new here lol. But I have a 1994 3.0 automatic 4wd and I just redone the head gaskets and now it sounds great. But I was getting ready to take it for a test drive and it was doing fine until it was going to hit second gear. The truck lost absolutely all its power and about dies along with the check engine light coming on. Anyone have an idea..? I was thinking a tps or vacuum problem but I'm not sure

 

Have you checked for stored codes?