my truck will idle ok but when u give it gas it pops and backfires and runs like crap. i've changed cap, coil, rotor, pick up coil, fuel filter, plugs, and computer, nothing has helped. fuel pressure is about 30-35 while idling but when u give it gas it goes up to 40, don't really want to change the fuel pump and that not fix it. had it on three different computers and it shows no codes. any help would be great.

 

i would say ake it some someone who has a diagnostic computer, like the snap on solus to hook up to it. it show all of the engine parameters and stuff.

 

Your fuel pressure is normal, but it sounds like more of a timing issue. But just for grins and giggles, have you checked the catalytic converter? They have caused me similar problems in the past.

 

check timing, re gap spark plugs is all i can say. make sure vacuum advance line is not damaged or leaking.

 

i think the timing is all computer controlled on the magnumtrucks...

 

check your catalytic converter.