Every time I get into boost and then let off of the gas, it dies. It runs just fine when I'm cruising though. A friend of mine said it could be that I'm running rich but I don't know. I just have a basic T3 top mount setup with a 6:1 FMU.

Is your blow off valve recirculated?

How much boost are you running? Do you have an AFR gauge? If so, what are your AFR's looking like in boost?

Chances are you're running slightly rich in boost, causing it to flood the engine when you go from boost to high vacuum. Try re-circulating your blow of valve like Razi said.

BOV issue. Disconnect the BOV or block it and see if the symptoms go away. Having a BOV vent previously metered air into the atmosphere creates a very rich condition on decel. This causes stumbling and stalling, very common btw.

I'll disconnect my BOV today and see what happens.
I'm only running 8psi and I don't have a AFR gauge so I have no idea what my AFR's are like lol.

A pic of the MAF and BOV setup would help as well.

Oh yeah, I forgot to mention the MAF thing. Sometimes having the MAF too close to the turbo inlet will cause some weird things to happen.

-Chris28

recirc or go blow through and keep the sweet sounds

Alright so I removed the BOV and the problem stopped lol. I'm going to put it back on and recirculate it back into the intake.

Quick question though, should my BOV release air every time I quickly let off the gas, or just after I've built up boost and let off the gas?

Just after boost is built, if there is no pressure there is nothing to release.

Would placing the bov aimed at maf/filter in close proximity work? That way you can run a bov/bypass without messing with piping.

Would running a bypass valve with a bleed valve rid this problem? My rb20det would just kind of surge when cruising if I didnt recir.?---it was a dsm oem unit same junk

^maybe putting a small hole after the maf would simulate the bleed valve and allow ecu to compensate when bov open.... Buddy mentioned this as a way to lean out a rich FLASH JWT etc. send outs. <--i was kinda doubting that would be a good idea --ignition timing *???

Can you elaborate on your set up walbro, t3?? vortech? --are you just readin plugs or wingin it hahaha



Lastly, from other threads i guess safc can be used to "tune out this problem. Dont know if it could work with fmu in place?

biggie wrote:Just after boost is built, if there is no pressure there is nothing to release.

kind of.. in theory this is right ^^ but if you think about it, when you are accelerating at (lets say) 0-1 inches of vacuum. you suddenly let off the throttle and the throttle body closes. the turbo is going to continue pushing air as the turbine is still spinning and the blow off valve will release air. if you have a loud blow off valve, or a whistling one you can easily hear it.