ok, i was driving home today from a friends house, and when i pulled out to my street i gunned it. well i already have a bad hesitation (recently i was told it was caused by a bad injector of mine) and after the horrible bog i witnessed flames come out the rear of my hood to about a quarter way up my windshield. why would my TBI backfire so horribly?

 

What is your base timing set at? If your timing is way off the map you can have a nasty backfire through the TBI.

 

Not to say your wrong, matter in fact i'm sure youre right but, how so would that cause it?

These computers have knock sensors which if pinging is detected they automatically retard timing so there won't be any more damage to the motor (at least that's how i thought it would work). You'd have to be pretty far advanced to have it do that and your motor would most likely be pinging with that much wouldn't it?

 

Its actually the other way around. The timing is too far retarded which causes the backfire (no detonation). Also, you can have audible knock even with the sensor present. It doesn't correct knock if you run your engine out of its range.

 

well that helps i appreciate you clearing that.