Seeking some help diagnosing a issue I've been having.
The car drives fine, the minute you do a WOT pull and shift in the next gear i.e. 3rd-4th the car loses power.
I've been advise that it could be valve float, we've check the tune, we also did a boost leak test and nothing.

The car is a built 2.0, PTE 6766 tuned on AEM infinity with KIGGY BEEHIVE SPRINGS, the valve float isn't noticeable on the dyno graph could anyone point me in the right direction

 

Valve float isn't caused by making a shift. It's something else.

 

Restriction somewhere or I had a situation where the butterfly in the throttle body broke a bolt and was a leak. Car drove fine everything was normal but car was down on power.

 

Here is a pull on the dyno. You can hear the car completely lose power in 4th.

I’ll check the throttle body later

 

What fuel pumps are you using? Does seem odd it does cut out like that. If the tune is spot on then idk. Doesn't really seem like valve float though.

 

That hard cut is 1000% not valve float.

 

Thats what I was thinking too but wasn't 100% sure hince the fuel pump question.

 

Car has a mangafuel 750 along with a boost a pump

 

Have you checked the logs?

I have a very similar issue, albeit with much less power levels, but the car dumps timing after shifting to 4th. 10 degrees across the board. Can't seem to figure it out.

 

Yea man, I've check the logs.

Tuner says there could possibly be a restriction somewhere

 

It doesn't pull 3rd just fine and make 870whp them suddenly 4th gear a "restriction" comes out of nowhere.

 

Nothing in the logs out of the ordinary ?

If its passed all the leak down tests and everything mechanically is in order I would look at wiring and voltage. The jumper harness from the ecu being plugged in tight. And the other wiring to the ecu/coils/etc. Make sure everything is tight and has the correct voltage during a pull.

 

Didn't people have problems with the instapumps way back when? I remember reading a while back about people having some sort of issue but I don't remember. I am guessing your have -8 to the rail and -6 to the return? Or are you -10 feed -8 return? I noticed there was a pump gas version and a e85 version of the pump why I am asking. I am also guessing you have 2150's and are running more then 43 lbs of fuel pressure? If your not that could be your problem as well you may have run out of injector at that base fuel pressure.

 

You would see a fuel issue in the log. Injector duty increasing, fuel pressure dropping etc. A well tuned stand alone is going to have AFR protection enabled to cut at a set value( most set this around 12.2 AFR or so above xx psi.)

 

I ruled out the valve float as an issue as I spoke to Kevin from Kiggly Racing.

Turn the boost down to spring pressure and the problem still occurs.

The car pretty much goes to pig rich in between shifts 8-9-9.0. The car also has a generic fuel pressure sensor. Maybe I should try a AEM fuel pressure sensor and see.