I've been having trouble with my 8. Cant get past 6500 rpms at WOT. I'm still trying to eliminate possible problems. Its taking some time since I am a full time student at college. The symptoms all point towards the Auxiliary Port Valve. I've tried searching everywhere but there isnt a lot of information on it. I do believe I can still hear it cycling when I switch the key between on and off. But anyways, does anyone know if I do indeed have to pull the motor to access the Aux valves, or can I take apart the intake manifold and get to them?

 

You haven't searched enough. I hope your research in school is better :P

Click this

 

Sorry, didn't mean I can't find information about the RPM issue, but information about Auxiliary Port Valves

 

You should read more into the threads that are in the link. Or, you can use your own words, using the same method. Very handy tool

 

Faulty APVs wont cause that issue .

 

Just curious but why do you think this isn't caused by faulty APVs? I'm not trying to sound mean, just wanting to know more about it

 

Well .... would it help if I told you that in some turbo applications we purposely block off the APV to avoid over-spooling the turbo ? Those engines rev past 6500 without issue.

 

it might help if you told yourself that there is a significant difference between having a turbo forcing air in than an NA engine trying to suck it in

that said, an NA will go flat past 6500 rpm without the APV opening, not just stop revving ... there could be fuel or ignition issues if this is the case

 

That would make sense. So I take it then that the APV can only either be completely open or completely closed? I thought maybe it could only be opening a faction of the amount it should so that would explain why when I give it less gas it can keep revving it to 9 on half-throttle because it is leaning out the AFR

 

This may come as a complete surprise to you , but having a turbo doesn't mean you have to be boosting 100% of the time .
That said - perhaps my example wasn't the best way to illustrate why sticking APVs wouldn't cause his issue. But better than saying "because I know it isn't" which defiantSE3P didn't accept as an answer the first time.

 

Oh, well alright then

 

Just an update, it turns out to be my Deatschwerks DW200 fuel pump crapped out. I never thought of the fuel pump as the culprit because it only has 5,000 miles on it. I had replaced it along with the new motor. I installed a new DW200 and its running just like it should again. Lets see how long this pump lasts haha