stumbling and occasional backfire

[LTZ C20]

78BIG-TEN, I am running a regular GM HEI distributor with vacuum advance, no ECM input at all, on my TBI 355. It runs excellent. I do have custom PROM chips in the ECM tho and a modified wiring harness.

[roundhouse]

If its backfiring thru the air intake
That's a symptom of not enough fuel
Which is logical of your TBI thinks its supplying fuel to a 350 CID
When in reality it's supplying fuel to a 383 CID

Read up the efi section at binderplanet.com
That's the best TBI site I've seen


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[lnydam]

So turned out to be my eprom according to a guy at the shop a took it to, who is very experienced with these truck, He siad he could get an eprom made for my setup but would be about 600 bucks. I decided to just get an Atomic EFI kit

[Captkaos]

I would get a chip for it.  I wouldn't think it would be anywhere near $600 for a custom chip.

[roundhouse]

The guy on binderplanet makes new chips for $40 I think

All the software and hardware you need to burn your own chips doesn't cost anywhere near $600


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