dont know why but my car stumbles at 6500rpm. not much of a bucking, but it definately hesitated a bit today. not sure whats going on here. i need some help.

 

you may need to clean your injectors. That happened to me in 4th gear at WOT, and I blew my engine. cleaned my injectors, they were dirty (professionally). Cost me an engine, plus the cost of getting them cleaned.

 

how much does it usually cost to have my injectors professionally cleaned?

 

i believe it costs 250.00 from R/C engineering..24 hour turn around..

 

you think that might also be why my car has been backfiring. not loud, but a soft popping at idle. and it also nearly stalls on startup after the engine has been warmed.

 

i had that same problem with my car, if your NA its probably the line that goes to your boost sensor (lil black box on passenger side engine bay with one vac line on it that comes from where the lower and upper intake meet) if youve replaced the vac line to it, you probably lost teh restricter pill thats in the stock line, this will cause high rpm hesitation