Ok I am having some issues w/ the old car.

Here is the symptom:

At partial throttle and partial boost (1-12ish psi) I get a serge/hesitation. It seems to only show its face under those conditions. I don’t have any signs of this problem at WOT/full boost.

Coil pack is new, sparks are new, plug wires are newer and the fuel filter is newer. Fuel pressure is good and normal, the DFI is acting normal and egts are normal.

I thought it may be the map so I put a new one on and the problem is still there. I know it isn’t bad gas because it has been around for more than a few tanks and two different brands.

Any ideas???

What sort of surge? Does it feel like the car is bucking a little under part throttle?

Yep.

I had that problem when i had an iffy power/ground to my fuel pump. Fuel pressure looked fine, but the car would sorta surge/buck under partial throttle. WOT it was fine. Rewired it and made sure it was tight in its bracket and it's been fine ever since.

Are you running the HRC inline, or just a walbro? Mine did that bad with the walbro.

Holley intank, HRC inline.

Yeah the fp looks fine and the af reads fine. I will check the grounds for sure in the morning.

Much appreciated Dino

I'm thinking there's too much fuel during low throttle and acceleration. You might want to lower the TPS Acceleration percentage just a little. Also, in the base fuel map, drive around and accelerate; follow where the fuel cell travels and try lowering the fuel volume that way too. That should help with low throttle/map acceleration.

When we were tuning Matt_95tgs's car and the 8 injector setup, he was running really rich in part throttle boost, causing some hessitation and bucking just like you have. I agree, sounds like you are running to rich. Try leaning out your fuel map under part throttle boost/rpms and see what happens.