Jessee Vernoy

Help!! I bought a 98 firebird formula was told it was a 5.3. it has 241 heads and ls1 intake and cam. I can not give it full throttle, half at max! Car starts cutting out and popping through the exhaust and you give it full throttle and start about 4k rpm. It's not throwing any codes and only does it under a load but sometimes I have to let the car sit for about 20 minutes and restart after trying wot or will keep cutting out and popping I've replaced every sensor there is. The only thing I haven't replaced is the fuel pump. When I checked it at an idle it showed 80 IBS! Which seems really high but im at a loss with it I cannot figure it out. And also changed plugs wires and coils! And I've noticed that when I turn my headlights on or use my blinkers my voltage will go back and fourth between 13 and 14 volts

bigbomber5

Bad o2 sensors maybe?

bigbomber5

After re-reading your post I noticed you replaced every sensor.
Someone much more knowledgeable than me should be able to point you in the right direction.

bammax

If you're getting popping in the exhaust it means you're not getting enough ignition or you're getting too much fuel. First check your oil and make sure it's not getting washed out from excess fuel. That would turn an annoying issue into a nightmare fast. Then it becomes a matter of determining if it's ignition or fuel. That is a whole long process of various tests. Oil condition will get you moving in the right direction.

jaxcam02

iTrader: (1)

I would get a tuner to look at the tune it has to see if someone screwed up the tune.

02DroptopZ

iTrader: (3)