1990 Mustang 5.0 won't accerate past 3,000 RPMs

I have a 1990 5.0 with a powerdyne supercharger (currently discontinued) and I when I accerate hard it hessitates or bucks at around 3,000 RPMs know matter what the boost controller is set to or timing. I have a Walbro 255 lph fuel pump, vortec FMU, MSD boost controller, and Kirban adjustable fuel pressure regulator. Engine is stock minus Ford Racing shorty headers, 2.5 full exhaust X Pipe with flowmaster 40s. At first I though maybe its due to the 15lb. pulley but then I tried with the belt off the supercharger/ Just to see if it was getting too much air for the stock MAF and and injectors no change. I tried with and without the FMU and at every adjustable psi I could think of with the Kirban fuel pressure regulator and am now out of ideas. I plan to get 30lb injectors and a 73mm MAF with 30lb sampling tube but I've know of other mustangs the can run with stock injectors but I am out of options please hook me up with some input. Thanks all

LaserSVT said:

15 lbs on a stock internaled block? Thats insaine! I wonder if you bent some pushrods.

Oh well, check your plugs and wires. See if a wire is arcing out or mabey a plug or two is fouled/burnt. Also look at the power wires to the coil and/or ignition box.
If thats all good then you may have some bent valves from runing 15+ psi

Stupid question, do you have the resistor pulled? I actually know someone who forgot to put it back in after seting his timing and on his first run was boging hard after 3200 or so. Took him 5 hours to find the problem

Click to expand...

Plugs and plug wires are new so not burnt or shorted I plan on putting the 9# pully on when I get the belt that fits it but the 15# was on when I got it. I also tried running without the belt so it wouldn't blow too much extra air just to see if it would run right no luck though. while accelerating at idle and it doesn't seem like the rods are bent even though I know its not hard to bend them with over reving and boost I did that on a 347 I had once. Oh and the resistor is on I've played with the timing plenty trying to see if I just needed to find a sweet spot.

I have my gap set a .32 I've tried autolite 25s and 24s. I am aware powerdyne isn't as great as vortech and so forth its preety old. I don't have any codes that stand out 41, 91, 13 I think they were. I once had a 89 but its been gone since the last time I cleared it.