Bucking Under Boost

[dsm5150]

OK,CHECKED FOR LEAKS-NONE,CHANGED PLUGS,WIRES.STILL BUCKS BAD.now,my friend said while he was driving it it hit 20 psi a couple times.so i checked oput the timing andall is good.what would be casuing this??

 

[90DSMTurboFWD]

Gotta be a leak somewhere, for the 20 PSI I would check your Wastegate Vacuum line, it might have shot off.

 

[mccurdy]

fuel cut?

 

[BreathinHeavy]

im having he same problem at 20lbs but my karman is reading 3 hz all the time :thumbdown

 

[ASZRAEL1266]

with 20 psi i would think fuel cut also. The hrz you said there must be somthing wrong. Did you check to make sure the safc set up correctly? i am boosting 13-13.5psi and i pull in from 1850-2000 kar this is on a 16G

 

[BreathinHeavy]

i know i didnt think that was right but i have no idea where to begin i will check my connections tomorrow morning as have to work today:thumbdown

 

[boostedtalon]

Fuel cut @ 16 psi.

Need I say more, it is like hitting a deer.

 

[dsm5150]

well iturned it down alot.thing is it slows down if i go full throttle.if i go about 1/3 its ok.anything over that and it just bucks....bad.i checked all pipes for leaks,nothing,nice and tight.would the bov cause it if it was leaking??????im at a loss.

 

[boostedtalon]

Hmmm. . . First of all. . what psi are you running? Does it spike at full throttle, how often? Do you have anything onboard to take care of Fuel cut? Check and make sure there are no leaks around the maf, also do you have a noticeable exhaust leak? Did this start after a Mod? I am thinkin if it was a leak in your IC piping that you would never actually make enough psi for boost cut, and I am betting dollars to doughnuts that this is your problem, Is it cooler where you live, that cold dense air will raise boost also, I had to turn my controller down 3 or 4 psi so that I wouldn't hit fuel cut on the cooler nights.

Whatever it is I wish you luck

Boosted Talon

 

[BreathinHeavy]

well guys i experenced it again today it was under full throtle at 20lbs of boost with a nice big flame shooting out of the tail pipe. i have logged it many times ill be at 8 degrees of timing then it will shoot up to 28-32 degrees when the bucking takes place. im also seem to have trouble getting my car tuned in it is running way rich and my air fuel gauge is never still it bounces really bad except under full throtle it stays on the rich side of things. any suggestions would be nice if no one has any ideas im goin to altered atmoshpere in gaithersburg md thanks