Running without boost controller?

[nik95gs-t]

--------------------------------------------------------------------------------
Hey i recently bought a 95 gs-t that was stipped of a bunch of electronics and i had a problem with the lower ic piping blowing off. Ive fixed that prob and today i got on the highway and all of a sudden the car wouldnt rev past like 3000 rpms and i heard the turbo spooling but it seemed like the pressure was leaking somewhere so i figured it was the same pipe blowing off but after i checked all the couplers and pipes and doing a boost leak test i didnt find any break, cracks, etc. In neutral the car revs fine but in gear the turbo wont build pressure and or have any power after the turbo spools up around 3000rpms It just stops reving untill i let the pressure out of the bov. Is this possibly a cause of removing the boost controller and having the turbo overboosted or could this be something else?

 

[frankozz]

Are you venting the stock 2g blow off valve?

 

[LiquidX]

You have your positive pressure source coming from the compressor housing or j-pipe/lower intercooler piping to the wastegate? Is your wastegate functioning properly? Test it by hooking up a compressor and spraying air into the wastegate. Check the arm movement and be sure the flapper/actuator arm aren't becoming stuck.

My opionion is if you don't have ANY leaks, your flapper is staying open and you are bypassing exhaust gasses past the turbine and not allowing boost.

Removing the boost controller will not have an effect on your boost. It will open the wastegate at the wastegates opening pressure. A boost controller just allows you to run a higher pressure than what the wastegate allows.

Just re read part. Are you saying it doesn't rev above 3000 rpm? In gear and neutral? You have double checked all of your connections like the main one being the MAF connector.

 

[nik95gs-t]

It revs fine in neutral only in gear it stalls at 3000 rpms

 

[LiquidX]

Is your profile up to date? I see that you ahve a Garret turbo but no injectors or a way to tune. What psi are you hitting when you boost?

 

[nik95gs-t]

no idea just bought the car stripped of everything by the last owner profile is up to date except it has a stock t-25 turbo

 

[nik95gs-t]

Ran mint for like a week then what i explained up top just happened when i went to get on the highway one day

 

[LiquidX]

Plugs and wires good? Positive you have no boost leaks? How long does your car hold pressure when you do a boost leak test?

 

[nik95gs-t]

is there any way this can be a bad maf sensor when the idle is normal and only has problems in gear

 

[allrice4g63]

so its only doing that when the engine is under a load(in gear) have you tryed letting off the gas then getting back on it again does that help? are you lifters ticking? if you can answer yes to any of these questions it could be pulling timing my car used to do this until i installed the 3g revised lifter. the knock sensor could be picking up a lifter tick or as known as phantom knock.

 

[nik95gs-t]

actually just changed the oil today and every once in a while ill hear a lifter tick right after startup even though the oil is full. It is only doing it under load, but when i let off the gas then get back on as soon as the boost builds up the revs just feel like they are bouncing rev limiter and theres just a loud turbo sort of spooling noise untill i let the pressure off. btw this didnt get worse and worse it just happened out of nowhere one day i went to get onto the highway.

 

[allrice4g63]

just because u can only hear lifter tick doesnt meant that the knock sensor isnt picking it up. try a bottle of lucas oil stabilizer do a boost leak test and then post back.