91 gst bogs down around 3500+ rpms

[asd_gst]

i have a 91 gst its all stock besides for a air filter, hacked air can, and the basic free mods, the car ran fine and tonight i was driving home and around 3500-4000 it starts to shutter real bad , the boost gauge is showing boost but the car seems like it doesn't want to go anywhere, and it seems like the boost spooling faster now but it doesnt want to go faster, i honestly don't know what it is, maybe boost leak? maybe crack manifold? but it rides fine in normal driving without hitting boost at low rpms, so how do i do a boost leak test? and what else do you think it could be?

 

[PIMking]

I would assume boost leak somewere. check all your couplers.

 

[asd_gst]

if it isnt a boost leak what else could it be?
it randomly just started doing this tonight, earlier today it ran fine when boosting, then i went to work for a few hours when i drove home it shuttered around 3500 rpm, so im guessing boost leak but if it isnt what else could it be?

 

[PIMking]

What size is your fuel pump and are you running stock boost?

 

[silver bullit]

Could be from not tightening mas when you changed filter, mas is bad or going bad.

 

[asd_gst]

motor is all stock stock fuel pump, stock boost, maybe like 1-2 psi higher it has the bcs removed or whatever its called, jsut free mods done to it air filter, bcs, hacked air can... but it ran fine since i bought the car on the 1st of this month then tonight after i left work it started to shutter around 3500-4000 rpms, but when i went to work it ran fine...

 

[silver bullit]

Was it cold out?

 

[asd_gst]

it wasnt that cold but it never did that in the cold before, why what will the cold do?

 

[TurboT91]

Colder air is denser, meaning more oxygenated. I'm assuming he was thinking maybe fuel cut. Do a bosst leak test and see. If you search, there are many posts about how to do one. I would also invest in a real boost gauge and at least rewire your stock fuel pump.

 

[asd_gst]

could it be a broke waste gate? i just took the car for a drive under a little boost its fine but then when you give it all it has it seems to hit full boost sooner so could this be a broke waste gate causing me to hit fuel cut?

 

[blcknspo0ln]

I agree with everyone else. If your car is mostly stock, it most likely has not been overhauled with new gaskets and such. Get out there and do a boost leak test!!!

 

[asd_gst]

yea but if it leaked boost would it still run good in lower boost, the car runs fine you can boost its fine but once you hit it the boost spikes real fast and the car shutters would a broke waste gate do this?

 

[blownturbotsi]

Boost leak test. Just do it so we can rule it out, then we can move on to the next step.

 

[asd_gst]

yea im going to do a boost leak test ### thats what im thinking it is after driving around in it, then ill let you guys know the results