cbehage

This has been going on fro a while now. I originaly had an apexi bov. I removed it because I thought it was causing the problem.

Now with it removed, when I give it gas, then let off, it flutters. I can hear it comming out of the air filter. Could it be releasing pressure back into the engine?

It did this with the bov on also. It also wants to stall when I first tap the gas on normal acceleration. I am pretty sure the bov was venting at low boost.

Any ideas or sugestions are appreciate

a_gut

Umm... compressor surge? My guess is you didn't have the bov hooked up right. Now with the no bov, whenever you let off the gas (ie, close the throttle plate) you are causing compressor surge every time.

JonGTR

With the compressor surge, the air is traveling back through the intake and the MAF is reading it. Yes, even though it's backwards air. So the motor isn't getting the air that is reads, and dumps fuel. That causes the stalling.

Jaws021

how do you have your vacuum lines hooked up... (when you had the BOV)

please be VERY detailed...

cbehage

from the Im is one lineto the fpr with 2 t fittings. First t is the boost gauge, second is the bov then to the fpr. The boost gauge reads accurate so I would assume the bov does to.

I guess i'll try and put it back on.

Thanks for the quick help guys.

a_gut

Well, that's a small ass vaccumm line to use for your bov. The bov vents when there is a difference in pressure on either side of the throttle body - that fpr line, especially since you have it split between 3 things, isn't providing enough of a reading to the bov for it to vent. Try using a stronger vaccumm source and dedicate that line to your bov. The brake booster or pcv vent line should do, I'd say.

cbehage

Well, I put it back on. Temporarily disconnected the boost gauge to have one less T fitting.

I also found a clamp kinda loose on the pipe comming from the turbo to the intercooler.

My question now is, how would Alpine sell it without a BOV if it surges without one?

I'll keep you guys posted. Haven't had time to drive it yet.

So you think I should T the gauge from the fpr line and T the BOV from the brake booster line?

hamhead

Cause Alpine is a bunch of cheapies. It makes them more money per kit they sell, and since it runs without it, they don't deem it necessary.

Any turbo at any PSI is going to get a longer lifespan with a blow off valve in the system somewhere.

cbehage

Put the bov back on. Stopped the fluttering. Still wants to stall.

I think I had the BOV tightened too much.

MAXXTIB

Are you clamping your MAF voltage with a piggyback ecu, when your BOV is venting it's letting out air that was mesured by the MAF but it never makes it into the motor so your dumping fuel everytime you BOV vents, I use the emanage to clamp the MAF signal when the BOV vents and it runs fine, before I had the emanage I had a simular problem, every time I would come off boost and my BOV would vent out I would go rich as hell for a few seconds and my car would bog down till it cleared out all the extra fuel, I never stalled out but it came close. A quick fix would be to get a BOV that can recycle the air back into the system after the MAF so it won't measure the same air twice.