I have a 1987 Grand National that I bought from the original owner. He said that there were no modifications done to the car. When it shifts into second and the boost comes up, it hits 15psi which is max. At this time it starts pinging and cutting out. I have checked all vaccum lines and replaced a few. The performance of the car does not seem to be affected. What can I do now?
Hi
You have a leak in the rubber hose going to waste gate. Pressure is what closes waste gate. This hose is close to exhaust side of turbo and burns thru often. When there is a leak the turbo puts out full boost.
Phil
I have already replaced that hose. Did not fix the problem. My next move is to put a vacuum gauge on the waste gate to see if it holds vacuum. I'm still open to suggestions.
I used a vacuum pump to pull vacuum on the waste gate control actuator. It held. Next I am going to replace the fuel pump. Has anyone experienced a similar problem? Help please!
Could be a bad fuel pressure regulator.
frank
I don't think pressure is the problem. I think it's more of a volume thing. But I don't know. I am new at this turbo thing so any help is appreciated.
Sounds like you may have a bad wastegate solenoid.
My car did the same thing a few years ago and as soon as I replaced the wastegate solenoid it ran mint!Hope this helps.
Is there anyway I can check that without replacing it? I hate just throwing parts on.
I don't know if there is an easy way to check it or not.
But 9 times out of ten the problem you described ends up being the wastegate solenoid or a vac. hose to the wastegate and you already checked the vac. hoses.
It turned out to be the coil pack. It was completely open between two of the cylinders. I am so glad I got this problem resolved. Thanks
yes the coil pack is wut does it mine did the samething and i just firgured it out yesturday.