Boost issue?

[Wizeman76]

Here's the deal. I've turbo'd a N/A EDM eclipse, using a stock 14B turbo with stock wastegate actuator (vacuume line hooked directly from the J-pipe to the actuator).

From startup, either warm or cold, I'll go for a drive and car boosts fine to the standard 7psi of the wastegate. After around 30 seconds of running awesome, the car then will only boost to 3psi. If I turn off the car and let it sit for about 30 seconds, then turn it on and go for a drive, the same thing happens again, full boost for 30secs then only 3psi after that.

Any ideas??

 

[marcmsj]

Have you tried doing a boost leak test? I would start there. I would also check the wastegate actuator, it could be sticking open.

 

[drivemusicnow]

I would second the inspection of the wastegate actuator, look for full range of movement of the flapper and that the linkage is not getting hung up anywhere.

If you have an air compressor, check the actuator with 3 psi, 5 psi, 7psi, and 10psi and see how it reacts. I know that the stock actuator is designed with the stock boost control solenoid in mind, but I wouldn't think that would make a difference.

 

[anmGST]

I would also check the wastegate sounds like it's either opening to soon or sticking open just make sure its not sticking..

 

[Wizeman76]

Thats awesome thanks for your help guys I really appreciate it. I'll try the suggestions and let you know how it goes.

 

[Wizeman76]

The wastegate rod is really loose inside the wastegate and there's no way to tighten it, you can literally pull the rod in and out an inch, so it looks like it was at fault - I've ordered another one so i'll install it and see if it fixes the problem.