Pontiac Repair: car troubles, pontiac grand prix, catalitic converter

Question
I have a 1991 Pontiac Grand Prix SE its a 3.1 and its lacking power and I'm not sure how because it has rebuilt heads and i just did a tune up. Is there any way to know if its jumped timing without a timing light or know why it might have lost power?

Answer
Hi Andrew:

well it can be a lot of things it doesn't have to be an engine mechanical issue unless it cropped up just after your engine rebuild. It can be an issue with low fuel pressure due to a bad pump or a restricted fuel filer. I belive those engines had between 34-38 PSI. You didn't mention if you changed the filter or not. it could be from a plugged catalitic converter to tell that or not unhook the front pipe going to the catalitic converter and drive it. you could have a bad misfire but you didn't mention it running rough... It could be a mechanical issue. A compression test may lead to a jumped timing issue and then again it may not. Hope this gives you a few ideas. Good luck :)