I've been trying to diagnose this problem for the last couple of days but can't seem to get a handle on it. What happens is @ 2k RPM when I go WOT boost will start to build and by @ 2.4k RPM it feels like I hit fuel cut as the engine kind of stalls for a second. my A/F is around 12.8-13.5:1 (depending on gear) and boost is like .2-.4bar (again depending on gear) when this happens.

SO far I've tried adjusting the accel enrichment values in that RPM range. Adding and removing timing in what I think is the load area (between 100-140). Change the target A/F number. I even tried to load the stock map back in but none of the above worked.

Anyone have any ideas?

 

Sounds a little lean. Check your plugs also.

 

Slipping clutch?

l8r)

 

running lean was my first guess also. I've set my target A/F richer then stock trying to fix the problem but that hasn't worked.

Plugs are NGK bpr7es (IIRC) gapped to .026. not sure why that would be the problem but I can throw the stockers back in to eliminate that as a possiblity

 

I'd try closing the gap to .022

 

check your FPR, My stock one took a crap around 15k miles,

It wouldn't raise the Fuel pressure and i was going lean no matter how much fuel i added.

 

I don't get misfires at any RPM though. This doesn't feel like a misfire either, kind of feels like fuel cut.

 

humm, other then adding a FP gauge is there another way to check that the FPR is working correctly?

 

A/F is around 12.8-13.5:1?! on pump?! That is FAR leaner than I would feel safe running on pump, and would be damn borderline on C16 imho.

 

Im with TTP on this one. Sounds like you may be blowing out your spark.

 

Not on spoolup. Those numbers are normal when coming down from closed loop 14.7 to open loop. You do lean spool, then drop down to the 11s after hitting full boost. Remember, he was talking about 2400rpm. I don't hit peak torque until 3700-3800rpm (full boost), which is when my AFRs begin to dip under 12 and stay there.

 

If I was running those A/F numbers at say peak TQ they yeah it would be a little crazy but you have to take into consideration the load on the engine. Between 2-2.5k RPM I don't have more then .4bar which is < 7psi... so those A/F's are safe. Besides that I've already tried dropping the target number below the stock map and it did nothing. I don't think its a lean issue.

 

I will close the plug gap to rule it out but I don't think I'm blowing out the spark at such low boost levels.

 

sounds like you have a leak on one of your pipes.
But logs would show rich.

 

sounds to me like a fault in your fuel system somewhere. Maybe the FPR as mentioned above...I had the exact same symptoms when I had the rubber gasket on my fuel pump slip out of place and was not getting adequate fuel pressure