*EDIT* for those who want the short version; car won't reach full boost until 4000rpm on stock turbo. Also have light flutter under low boost. This is all after getting the car back from the dealer. Only thing changed was the clutch, flywheel, synchros and some shaft to eliminate the p0300 CEL. Nothing else was changed. Checked for boost leaks and none found.



A little background info to hopefully help with the diagnosis:

Last month, I decided to take my car to the dealer to get some warranty work taken care of. I was tired of the annoying phantom 0300 code continually popping up and the clear coat on my spoiler was beginning to peel. Also, no matter what I did, I couldn't get rid of the dreaded high rpm lockout the ACT clutch was notorious for so I took this opportunity to replace my ACT clutch and flywheel.

After about a month at the dealer, they finally call me to let me know the car was ready. Cost me a whopping $68!! Thank God for the Mitsu warranty! Anyway, turns out my clutch was fine and it was my flywheel that was bad. Dealer told me that the flywheel actually fell apart as they were taking it out. Interesting.

So the following weeks, I proceed to break in the clutch with about 500 miles of non-spirited city driving. Everything felt very well with the exception of the car wanting to stall everytime I came to a stop. Now the only other time I ran into this problem was when my BOV had a leak. Never ran into the issue with my act flywheel. Not sure if the Fidanza is lighter than the ACT but I really didnt think that was the culprit.

So after the break in, I'm finally able to dig into her and at first I didn't notice any problems since my main focus was on the high rpm lockout which had completely disappeared. Tranny shifted flawlessly (mitsu also changed out my synchros amongst other things)

I go to the local drag strip to do a little test and tune and to my suprise, my et and trap speeds are dramatically lower than usual. 13.3@103 was my best time of the night. Now the track temps were high at 148 degrees during the day and 105 at night, but it was never a problem before. Anyway, the next morning I take her out to do some datalogging to see if I can diagnose the issue. Turns out, not only am I not reaching full boost till after 4000rpm, but my datalogs show that my load is down by about 20-25. Dataloglab is showing my power as being down by about 50hp.

I went through and checked all my vacuum lines for a leak. Nothing there. Checked all my IC piping connections for a leak or loose clamp....nothing. Disassembled my bov and loobed her up to see if that would help.....nothing. And speaking of BOV, I'm getting some flutter at low boost levels which has never happened before.

What could be the problem?????

 

Here are the before and after datalogs.

 

maybe the dealer reflashed your ecu back to stock?

 

I checked that as well and it's the way I left it.

 

check for boost leaks

 

did not see an afr log. do you know where you are at?

 

Don't have my wideband hooked up yet.

I checked all hoses for leaks and found nothing visible. Don't have the equipment to do a leak test so if I dont get the problem fixed by tonight, I'll be forced to take it to a shop to get it tested. Very frustrating