ok guys,i own a 90 firebird 336 cu inch TBI,formerly a 305 lo3.... anyhoo a couple days ago noticed a slight bog or backfire- if you will,under load, and it didnt do it again till this morn.... THIS TIME its severly bad!it idles fine-but any normal gas given and (she boggs soo baddly) i had to nurse her home from work.i went ahead and checked for trouble codes and(NONE)!i checked for loose spark plugs..(none). i took off the cleaner lid......whist shes running, and gave her gas, and the left injector coughed at me...? is it the obvious.....{injector}? or could it be the {TPS}? ORRRR maybe perhaps water in the tank??? IT IS RAINING BUCKETS RIGHT NOW!---but,it wasnt raining when it (FIRST HAPPENED) need help guyz,please point a fellow third gen head, in the right direction! TY BRAD! by the way shes like the blue one up above.....

 

more than likely you got some trash in the injector, but also check the fuel pressure. I would also change the fuel filter while your at it.

 

thanks fot the heads-up on that! any other suggestions,on the possibilities? -brad

 

I second the fuel pressure. Sounds like a possible lean condition. Also try some injector cleaner.