I am having boost issues and have some questions.

Currently my car is only boosting 11 PSI max. Process of elimination leads me to thinking there may be some electrical connection issues from the ECU to the boost control solenoid.

Here are some questions:

• The harness from the boost control solenoid, where does that go to? Straight to the ECU?
  
• If connected to a voltmeter, what can I expect to see from the wire harness that connects to the stock boost control solenoid(at idle and at different driving RPM/Speed). Or when do I expect to see a change in voltage when driving?

Any help would be appreciated. Thanks

 

Could be boost leak

 

11 psi isnt even stock wastegate pressure, so you probably have a leak, or a bcs problem compounded with a leak. Also the ECU should throw a code if there is a problem with the bcs circuit. Do a boost leak test then proceed from there. While doing the boost leak test check for shaft play on the turbo to make sure that isnt dying.

 

I have yet to do the electrical test but will post once I get a chance to do it. I might solder two wires on the boost control solenoid and jump it to the ECU to see if there is a break in connection somewhere.

During a boost leak test how long is it supposed to hold the targeted pressure if there are no leaks. I've done it in the past and there will always be a small drop in pressure(not sure where). But let's say I do have a small leak would it cause something like this? It seems like there is a straight cutoff at 11-12psi and nothing higher. I would expect to have inconsistent pressure 12 psi or higher if it is indeed a boost leak? The boosting is intermittent sometimes 11psi and very rarely 20psi. It's either working or not working at all that's why I think it's an electrical connection issue. What else could cause something like this? No CEL.

 

Doing a boost leak test your looking for leaks not necessarily pressure drop. Soapy water is a good aid as it will bubble if there is a leak. I mean massive pressure drop is bad but you want to keep it at a few psi above your target boost while looking for leaks. If you unplug the bcs you will throw a cel which is why I doubt an electrical fault. There are other reasons the ecu could pull boost, like excessive knock causing it to run the low octane maps.