shortyboy

ok,ive just installed the autothority maf sensor,chips and guru wastegate.i finally finish installing the wastegate and start up the engine.i rev the engine(from the throttle body) a few times,everything is ok,but when i try to rev it up again i get a huge BANG!!!!!soi jump back cause i thought the car was going to explode.im still in shock.what happened to my car?overlly rich?shooting flames?what?thanx in advance

nyda

Could it be a backfire? I could be wrong but isnt a back fire usually caused by running very rich?

'86 944 turbo

You might be running to rich.

87Porsche951

Its most likely caused from running too lean.

porshhhh951

no its caused by running to rich......i get back fire's every once in awhile.....at first i hated it but, now whenever it happens(once or twice a week) i kinda like it......lol......scares people.Whenever i am racing ...and boosting all the way to redline ..........as i change gears sometimes it will do it ..kinda sounds like a gun shot.

turbo944

hehe....my car with the Autothority chips does that now first/second or second third when I've been boosting way up into the revs. My brother (following me around just after I got the car and watching for it since I'd heard it and wanted to confirm it) has seen the fire shooting from my tailpipe (no kitty under the car on mine).

TurboTommy

This happened to me as well during "the dialing in the car days". Definitely too rich. Turned the fuel pressure down and it never happened again.

shortyboy

well,thanx for all the input all.but i think im running too rich cause ive also got a 3bar fpr which i think its causing the autothority maf to go super rich.ive switched back to guru chips and wastegate.but one thing still bothers me,with the autothority setup i had no popping when ridding a high gear(3rd or 4th),but with the guru setup i get alot of popping.pz and thanx

adrial

Get a wideband O2 sensor in the exhaust and end all the guessing....

Alan C.

How's your leakdown? Do you have any worn intake valves?

Alan C.