Last night I took the intake manifold off and did a thorough carbon scrub, taking time to soak and scrub each intake valve several times to get the most carbon out as possible. All went well! Afterwards, I reassembled my car, fired it up, and it sounded like it was running great. Took it for a test drive, and to my dismay, it will not get over 2psi of boost. Even at WOT! Drove it home and took it all apart again, and then double checked all of my plug-ins, and reassembled. test drove, no improvement! I do not even know where to start looking for the root of the problem! I would really appreciate some help!

Could an over-spray of the carb cleaner I was using have damaged a sensor or something? I covered everything with rags to avoid over-spray getting everywhere, but it may still have been possible.

Also want to add, no CEL came on during test drive. I drove it to work this morning, and the yellow engine light came on on the tach but not on the speedo. I ran my scanner and it said there were no faults stored in the ecu. I find that weird.

Will it hurt to continue driving the car in this condition?

 

Just thought of something.....

When I re installed the intake manifold, I noticed that there are two little vacuum lines that had popped off of their nipples underneath the intake and they go to what appears to be some kind of pump mechanism. Could this be the vacuum pump that controls the waste gate? If so, that may very well be my problem. The hoses seemed to have swollen and would not stay on their nipples. I am also unsure which goes where. Any help? One is longer a in a hook shape the other is short and straight. I secured them the best I could but they may be in the wrong place or have since popped off. Any ideas?

 

Check vacuumlines again,especially short endpipes and vacuumcanister too.If vac.lines ok, then check tank airvent valve and pressure conventer,both are under intake manifold. I have boost problem and I changed both valves and the problem was solved.If fuel tank goes boost pressure , then the most likely "tank airvent valve"leaks,sometimes no CEL,is mechanically broken,electronically ok.

 

Thank you for the reply! Is there anything specific I need to check on the pressure converter or just check the lines? If in fact the problem is due to the swollen vacuum lines, can I replace them with regular vacuum line from the auto parts store?

Also, where is the air vent valve and how do I test it?

 

UPDATE:

I solved the issue this evening. Took the intake off to examine the vacuum lines. Specifically the lines going to the "pressure actuator" that controls the waste gate. Upon close inspection, I noticed one of the lines had popped off but wasnt easily noticeable because it had been zip-tied to another hose and was held very close in place to where it was supposed to be. Once I put it back on and reinstalled the intake all was well! Test drove and I have boost again! Another lesson learned!

Anyone needing to do a carbon cleaning can do it easily. It just takes a little time and patience. Learn from my mistake and make sure all of the vacuum lines are connected before reinstalling the intake manifold and it should go alot smoother than mine did. In all, it could be done on a saturday afternoon, taking only a couple of hours depending on how coked up your intake valves are.