Turbo Wastegate Engine Service light error

[99GSX Swede]

Not sure if anyone has experienced this. I was not able to find any threads on it from my searches.

I have been trying the two different ways of hooking up a MBC as discussed on multiple threads. I had always ran my MBC with its vacuum source from the intake manifold and thought that I would give the compressor housing a try, to see if it made any difference on boost spike or spool up.

After hooking up the MBC to the nipple on the compressor housing, I noticed a slower spooling turbo. No improvement with boost spikes but I did get what at first felt almost like fuel cut. I though this was strange since my boost level was the same as it was when I got my source from the intake manifold. I lowered it by approx 1 psi and tried a 2nd gear pull. Within 2-3 seconds I hit what almost felt like fuelcut and this time my service engine light stayed on (boost was at 17psi). I checked the error with my logger and it showed as a Turbo Wastegate open error. WTF

Has anyone experienced this? Why would the wastgate blow open when hooked up to the compressor and not the intake manifold?

The MBC I am using is a Joe P. Before that I had a Turbo XS but I switched to try to reduce boost spike as well as that annoying bleed of hissing under the hood.

I have now switched back to the intake manifold and everything works great and I was able to turn my boost back up to 19 psi all the way to redline.

 

[reveal1123]

From what I understand, tapping off the compressor isnt a good idea. It gives the pressure at the compressor, before the ic pipes/ic. Since theres a pressure drop through the system, that boost level isnt what you see at your manifold, and isnt what "boost" your engine is seeing. I tap right off the BOV vac line. It seems many other people do the same.

 

[99GSX Swede]

that boost level isnt what you see at your manifold, and isnt what "boost" your engine is seeing. I tap right off the BOV vac line.

I have just read that some do go off of the compressor so I thought hat i would try it. Bad idea.

Also as far as what boost the manifold sees, should be the same since the boost gauge is actually only reading what it sees in the manifold. The only thing I can see as being differnet is the inconsistency of the boost level to the MBC when it is hooked to the compressor.

I just didn't realize it would blow my wastegate open and give me service engine light. I was just wondering if this was a common problem when running higher then stock boost.

 

[reveal1123]

My actuator arm actually fell off the flapper, leaving my wastgate open at all times. I never got a check engine light but I have a 1g, it obviously is different.