Leaking wastegate cover=Hesitation?
 

Im workin on my buddies 88 T2 & I cant seem to find a hesitaion prob. Heres a list of info.

Rebuilt 2k miles
down pipe & test pipe
NO Vaccum or Boost leaks.
Replaced ALL Manifold gaskets. Only exhaust leak is at wastegate cover.
New TPS! voltage is correct.
Timing is Correct.
runs VERY well & is very fast untill hesitation at around 5k under HEAVY load!!
If the load is small then there is no hesitation.
All grounds are hooked up & have good continuity.
Injectors were cleaned & flow tested by rc engineering during rebuild.

Posibilities..... I still need to check Fuel pressure. Possible fuel pump.
Air flow meter?
OR a Leak in the wastegate cover?
It is only boosting 9 lbs with a boost controller.

Can anybody help me?

take off the boost controller and see if that helps. I had some hestitations and spiking due to an MBC and right now I just have it running straight wastegate pressure and it's running better (but boosting around 6psi in 1st and 2nd and building boost slower).

No the problem was there before the rebuild or an of the aftermarket parts were installed.

how old is your fuel filter? did you try adding additional grounds? additional ground to the pressure sensor? Have you rewired the fuel pump so it gets correct voltage?

A slighty leaky wastegate will slow boost responce, and a badly leaking one may reduce boost, but it can't cause hesitation. Hesitations are caused by an interruption to fuel delivery and/or spark.

When does the hesitation occur? Only under load? Only at a certain rpm?

Yes. Only Heavy load & not untill right after 5K. I need to check the fuel filter. I have another one around here thats only got like 2k miles on it. I'll try that & I have a walbro too that's already with the sending unit. I might try that too.