Having a heck of a time figuring out whats going on with my EFI system. I have a 94 roller 351 bored to 408. Engine pulled 460HP on engine dyno with a carb setup. Now its in my car and converted to EFI. On the dyno it starts loosing power at 5500 rpm and appears to be running erratically. Almost like injectors are firing out of sequence....according to the guy tuning. Power barely reaches 310 at wheels. Using an MSD 6AL ignition.

Engine has a lunati 351 cam...so it's firing order is like 5.0 HO. Dizzy is setup in the HO/351 fire order. Computer is a reman A9L from 93 cobra...so they say.

Engine runs rough, almost like its missing power on one cylinder. Ran codes, all ok. Ran cylinder balance test and it passed....ie all cylinders contributing equal power. Fuel pressure is 55 psi (i know too high....need to get new guage to verify and lower pressure) using 30 lb injectors.

Tuner thinks i have 1 or 2 injectors out of phase with spark. Wonder if computer is not a 93 a9l....perhaps older NON HO computer...stickers are missing and case painted black. Switched all inkectors as well. Wonder if injectors too small? Also, tuner thinks engine should run like hell when pulling wires from one injector. In my case, we cant tell when one injector is disconected.

any ideas?

thanks