what can cause my car to sometimes back fire when i go above 2500 rpm's at idle ...the car doesnt like to idle when it is first started my check engine light blinks three times when trying to idle ???but when i go above 2500 it starts to backfire only when is is cold.after five minutes it is fine but sounds like it is trying hard to stay idiling what causes this problem ?? my car only has 52000 original miles it was my aunts car and it sat for a while iam going to try again tomarrow i guess iam searching for a bad ground or something help


this is what i done so far 1 changed fuel pump
2 checked my dist cap ''good''
3 changed my gas
4 checked my relays ''good''
5 new spark plugs and wires

 

It sounds like a "lean pop", what year is the car? This only happens when cold, after its warm it wont do it?

As far as the idle, do a search on TPS and min. idle air, adjust if needed.

 

MY CAR IS A 1986 Z28.. IT DOES IT SOME TIMEs EVEN AFTER IT Has ran a little while to . what can cause it.. it even doesnt like to hold idle when this happens ????

 

Ohm the injectors to see if one or more are bad, check the fuel pressure. Dose it backfire thrught the intake or the exh.?

 

IT DOES SOMETIMES POP THROUGH THE TPI IN THE FRONT BUT I JUST FOUND OUT THAT THE ALTERNATOR WASNT THE RIGHT ONE SO MAYBE IT WASNT GETTING ENOUGH JUICE TO THE OTHER COMPONENTS ON THE CAR BUT WHAT WOULD MAKE IT POP THROUGH THE FRONT WHERE THE AIR SYSYM IS HERE IS A PIC OF MY MOTOR MINED THE TAPE I FIXED THAT ALREADY THE MOROR WAS DIRTY AT THE TIME OF THIS PIC I STILL CANT FIND OUT WHAT TPI IT IS IT WAS SPECIAL ORDERD WITH THE PERFORMANCE UPGRADE IT HAS A 4 SPEED AUTOMATIC IN IT FOR A TRANNY DO YOU KNOW WHAT ONE IT IS ? JUST FIGURED ID ASK