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boost problem...

F

falcz420

New member
I have a 1998 GTP. For a while I've been getting half boost only when the car is at normal operating temp. When the car is cold, I'm able to get full boost. I've replace the bypass valve, put a mech. boost gauge, no vac leaks, rebuilt the snout on the SC, new belts, new SC tens, and still the same problem. Does anyone have any ideas? Would a clogged cat have anything to do with it? Canister Purge Valve? EGR valve? This is driving me crazy!!
 


you know when your car is below running temperature that the knock sensors havent turned on yet so you are actually experiencing true detonation instead of the car being able to pull timing to stop it?

with a clogged cat the car would be a super huge dog. EGR isnt active when youre into the throttle hard.

what is it reading for boost? if it is reading about 6-7 pounds then that is all that the stock setup makes..
 
sounds like your boost bypass is messed up, but you said youve replaced it. have you tried to take the lower vacuum line off the BBV and ending the vacuum line at the FPR?
 


Pulled off the lower vac. line on the bypass valve, and that fixed the problem. now what do i do to fix the problem? The bypass valve is new. any ideas?
 


It means the solenoid is bad or there's a problem with the wiring. Check the wiring first some people find corroded contacts or loose connections.

I have a couple of extras laying around, can't guarantee they're good, though, as I've never run them.
 
Not exactly, to eliminate the solenoid, you would just leave the bottom of the actuator open to atmosphere and cap off the vac line after the FPR. Be aware, though, the computer uses the solenoid for traction control and for bleeding off some boost at the shifts, so you'd want to keep an eye on things to make sure you don't run lean or anything during shifts. The computer MAY also throw a code, but that seems to be hit or miss.
 
I think it throws an SES light, not TC/ABS. TC/ABS is a bad wheel speed sensor the vast majority of the time.
 


I just took off the lower vacuum line and my boost problem is gone.... after the BBV.. what part is it called that the line goes to?
 
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