Overboost?

[TriShield]

Last summer my car developed a "popping sound" and bucking at WOT at full boost (near or lighted red LEDs). I followed some advice I recieved and replaced a few things on the car and it never fully solved the problem.

In addition when this problem was occurring the lines to the turbo were soaked with oil.

I replaced the wastegate solenoid and the little rubber hoses so they don't blow off anymore, but the car still has sort of a "pop" to it but not near as much bucking.

No I don't have an aftermarket boost gage yet, working on getting a GNX dash for that problem. I also don't have a scantool yet (because I can't find a cheap laptop for the life of me). What are things I can look for without these tools?

 

[Cakes]

I dont know if this will help much but my car was doing a similar thing, bucking (pulling out timing) while at or near WOT and Jack Cotton told me it was my ATR Pitbull chip. It just had too much timing built in to it since it was such an old tech chip. You may want to try a different chip. I put in a Jay Carter 93 octane chip for 40 lb injectors and the car had a whole new attitude. No WOT bucking and plenty of power all through the rev range. Just a thought that worked for me.

 

[WarpSpeed]

How old is your Accufab FP Regulator? And is it blue? If it's new, never mind.

 

[6pak2aV6]

Get a boost gauge & get to the problem of the car. Do you have an adjustable wastegate rod? If so have you tried lowering the boost by adjusting the waste gate rod (making it longer)?

DOes lower boost sovle the problem?

What is your FP set at??

 

[TriShield]

Stock wastegate rod, 1991 Dynotech chip in the car. Accufab regulator is not even a year old with pressure set between 30-35psi.

 

[WarpSpeed]

Might turn the fuel psi up some,, the computer will adjust for it for driveability, except at WOT. That chip may call for a minimum setting higher than 30-35.

>>the lines to the turbo were soaked with oil.

You mean the vacume lines to the wastegate actuator? If so, the only way that can happen is from the turbo, which is a bad sign. Also, that means there's probably oil in the IC too.

 

[TriShield]

It seems to have stopped oiling the vaccuum lines to the solenoid after I replaced it. The old lines were badly worn out and kept blowing off the turbo.

Does this mean my turbocharger is shot?

 

[John Larkin]

Lots of good ideas here already, particularly raising fuel pressure. Start at 42 lbs with the vacuum line off the regulator, then reinstall the vacuum line. The stock rod on the wastegate actuator won't allow alot of boost, but do yourself a big favor and get a boost gauge, even if it's just one on the pillar. You can sell it when you get your GNX dash. It's just not a good idea to boost without a gauge; the factory LEDs are not reliable. If you have stock injectors, I think you'd like a Thrasher 92 chip. They drive good; I used to use one and liked it. Follow the instructions if you go this route. Everything I suggested will cost you around $100 and you'll likely have a more fun-to-drive car. Do the spring cleaning and clean out that intercooler and throttle body for sure http://www.gnttype.org/maint/basics.html (another $100 if you change the O2 sensor too, otherwise around $75). Good luck. Your turbo is probably fine.