One last problem to fix before I can tune the car, help please!
 

Alright, Ive got 99% of the known bugs worked out of my motor. One last thing to fix and its time for some tuning.

Here is my issue:

When under 4000 rpm and boost is above what looks to be 3-4psi on my aftermarket gauge, the car will studder, sometimes backfire, hesitate, all sorts of crap. BUT! once I make it above 4k rpm, everything seems to smooth out and the car pulls fine to redline. I just experience issues BELOW 4k rpm. My only though is that there is something wrong with the boost sensor, either not sensing load or who knows what. Ill be going through the FSM to see how to test it.

Any ideas what could be causing this?

The secondaries are coming online and the car is untuned. That's about what happens. :)

sounds like poor tuning. are you keeping track of AFR's when this happens? and why are you redlining and boosting if its not tuned yet?

Then why does it smooth out above 4k? Thats what confuses me. Are you saying the secondaries are pretty much flooding the car at lower revs?

Yep.

Could also be in combination with the 3800 RPM hesitation.

I dont know about the 3800 deal, Ive got what I think are pretty good grounds run and the 720s are only like a year or 2 old.

Unplug the boost sensor from the electrical connector and see if this changes the problem.
This will also eliminate the boost sensor as a problem.


-Ted

:wallbash: Didnt even cross my mind haha

Sounds right, your going super rich when the secondaries come on line. You will be able to smooth that out with proper tuning..

stealth

I have the same problem when my secondaries come online. I am running 720's all around with an old f-con so my system is all f'ed up. A tune will fix it man. I need to get mine tuned when I get my standalone.