back firing

[erythnul]

i have a 93' motor out of a gt in my 67' stang aand it keeps back firing when i rev it to 3k rpm ... the headers get cherry red like the engine is running to lean ...my uncle put the engine in a couple days ago and he cant figure it out .. he's been a mechanic for 30 years and still cant figure it out .. we had some connections at the ford house and managed to get this machine that reads the cars computer but the computer was saying everything was ok .... has anyone every had this problem before?? comments will be greatly appreciated .thanks

 

[HISSIN50]

He might have used a scope.

What is the situation with the engine management and induction? Do you run a carb or did you transplant the EFI (puter, injectors, emissions stuff, etc)?

The cobra puter was kind of a dog to start with, so that is probably not helping a lot. But that is not the issue. More info will help.

Good luck.

 

[Daggar]

... and if it's a Cobra computer, what maf sensor and what size injectors is he using?

You've got a PM JT

 

[erythnul]

hey

the only things i knwo is that we kept the engine fuel injected right now sinse we couldnt figure it out we just switched it to carb. i was just wondering if anyone had this problem and how they fixed it .... i dont know what kind of mass air flow sensor he used ....everyhting is stock gt

 

[TheUser]

the only things i knwo is that we kept the engine fuel injected right now sinse we couldnt figure it out we just switched it to carb. i was just wondering if anyone had this problem and how they fixed it .... i dont know what kind of mass air flow sensor he used ....everyhting is stock gt

that sounds contradtictory to me, but I assume it's fuel injected if you pulled the codes from the computer.

What did you set the timing at? I assume he set the TPS. What fuel pressure are you running? And like Daggar asked, what size MAF and Injectors? I assume they're from your car, so they do match right?

 

[HISSIN50]

Oops, I did not see the GT part. My bad. I suppose it is still worth making sure the puter, injectors and MAF calibration are of the same mind.