So I bought an 03 Evo a few months ago tuned on e85. Was idling like **** and running kinda rough. Wanted to switch it over to pump. So I got it tuned by JR tuned at shift fast performance in fort mill sc. He's a reputable tuner and I made good power and he fixed the idle. I first got it tuned a month and a half ago and it had a few of the wrong parts in it from the last owner such as the incorrect Evo ix spark plugs in it(shorter, barley reached coil) low temp 63 degree t-stat that had a recall moshimito no longer makes(threw p0128 engine code). Now I have a 68degree low temp. I also tried replacing fuel pump, front O2 sensor, coils, plugs are br8eix, checked boost leaks, and sent the injectors to FIC to have them flow tested and cleaned. They were pretty inconsistent from one flowing 1028cc/min compared to 1108 on another. All flow at 1108 now.
The car constantly had a REALLY bad hesitation and bogged really really bad and I found a spliced wire going to an injector. I pulled it apart and it was for sure a bad connection. Fixing that made the biggest difference and fixed the bad bogging and almost impossible drivability.
I brought it back to jr at shift fast performance and had him look at it and put it back on the dyno since I replaced all those parts and fixed the wire. He said its running good and WOT is good and he got it a little better. It is still there though and hesitates really low rpms, it will also mis and hesitate when shifting gears sometimes. Only happens at partial throttle or heavy throttle in really low rpms. Wot is perfect.
Mods consist of
Fp green, gsc s2's, 1100 fic injectors, Walbro 255, Tial bov, Fmic, maf delete map tuned and other basic bolt ons. Car made 410whp on their "heartbreaking" dyno at 25psi when it was 97 degrees out. Hoping maybe people have any clues. I had a guy at the shop tell me it was the thermostat and I should run an Oem t stat and I'm tempted to do that now. Only other thing left I can think to replace is the Oem FPR. A guy a the shop also says it's the FIC injectors are **** and id's would fix the problems but I had them tested so idk. Again hoping for some answers or ideas. Thanks for the space.

 

Tune is likely the issue. Nothing wrong with FIC injectors, you have a nice list of mods. That dyno is far from a heartbreaker unfortunately, stock turbo e85 cars make right around 400whp on it and fp reds on e85 make in the 500whp range so it reads similar to a dynojet.