Hit em Up

iTrader: (3)

Ok trying to give a friend a hand on getting his car running normal.It's a 95lt1 with hot cam and mail order tune.It has a intermittent miss usually at lower rpms and then revs pretty smooth afterwards.I've checked fire order,redid valves,replaced coil,mass air and ign module with known working parts.I pulled harness out the opti to find moisture in it from a leak.Blew it out for a while with air compressor and it ran better as a result.So I'm pretty sure the opti is at fault here but what I can't understand is,what is causing the backfire out the intake? Also you can completely cover the mass air and motor doesn't stumble or cut off,and you can feel air blowing out the intake vs be sucked in!! Anymore ideas for me to check?? Thx

FAD2BLK93

If u are covering the TB and it dosen't die then there is somewhere else air has to be entering the engine. Vacuum leak? A backfire under acceleration usually denotes a lean condition.

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iTrader: (3)

I agree but I sprayed starter fluid all around intake manifold and intake tube and there was no idle variance at all.And what would cause the air to blow out the intake tube vs being sucked in? The car idles very well considering and still has marginal power.Thx

quik95lt1

iTrader: (7)

sounds like there is a massive vacuum leak somewhere.......that will cause the pop out the intake too the motor is lean its chasing fuel up the plenum can be caused by unmetered air going in........try plugging off your power brake booster line and seeing what happens......

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iTrader: (3)

Thx you were right I bypassed the brake booster and this thing runs like a champ!!!! That was nowhere on my mind appreciate it...