MK_951

hey, I have a completely stock turbo motor and when I boost and hold it, the car bogs out and won't let me push the car anymore. I know that stock the car should be running 11psi but my car is pushing around 16psi when it cuts out. I have a shimmed wastegate and I don't know if that could be my problem. I don't beat on the car so I've only witnessed this about three to four times. Also, could the computer be going into a safe mode of some sort so I don't over-boost?

Black51

It sounds like the car is going into overboost protection mode. The shims are allowing the turbo to make more air pressure than the stock CV will allow. Take them out, or take out the CV and put in a manual boost controller, with new chips.

VanhireBoys

I had this problem as well... It turned out to be the Wastegate actuator valve had a broken leg.. This meant that the wastegate would not open..!

I operated the wastegate with a bicycle pump and saw it was free ! Followed the pipe up teh engine and there it was...!

Never assume - Keep an open mind but a shimmed wastegate on a standard motor and you are going very close to the overboost !

MooreBoost

good be spark plugs, cap, rotor, coil, vac/boost lines, dme, cycling valve or wastegate.

Black51

If you had an aftermarket boost gauge, you would be able to tell if there is an engine misfire under boost by looking at the needle. That would indicate a plugs, cap, rotor, etc... problem. But if the car is simply not going into boost, I would take out the WG shims.

Stephencs601

Also check for Vacuum leaks. Notorious problem.

Porsche Ober

does any body know where I can get a good set of vacuum lines...like a kit or something, or is there a better way to do it. I am having the same problem, and figure I should start at the lines because the car is old and they do need to be replaced anyway. How do I check my wastegate while Im at it?

rlm328

Lindsey Racing has everything available to fill your crack pipe.

Porsche Ober

Sweet. I didnt know that. thanks