Info:
I have swapped a 350 hydraulic cam for my 305 TPI. I am currently running stock MAF, injectors, and fuel pressure, and custom cam Lift 477 480 Duration 224 231 Lobe Separation 114 Intake Center Line 110. The compression is about 8:1 for a future forced air application. I have talked to both Howell Engine Developments and TpiSpecialties, which believe that the stock computer should have no problem handling these specs.

Symptoms:
The car idles pretty strong, but slightly rich. If I throttle it really hard and fast I get a lean backfire through the intake. Upon driving it will fall on its face with anything past a ¼ or 1/3 throttle, but will eventually catch up and run. Also, the air/fuel ratio gauge goes lean, but eventually reads normal. Again, if I hit the throttle too hard a backfire occurs through the intake and the car just sits there.

What I know so far:
The computer will not allow me to pull any codes from it (not even the 12 code that tells you that you are in the computer check mode), which leads me to believe the computer is bad. The timing sits mostly at about 0 BTDC until a certain RPM is reached and then jumps to 8 BTDC, and never goes above it. Also I am having a low and steady vacuum reading, about 13 in-Hg, which could be caused by the incorrect ignition timing according to the Chilton’s manual.

 

sounds like a dead CPU to me .. check your fuses ..power to the
CPU ...etc ...

TVP

 

My car had some of the same symptoms. It turned out to be the fuel pump. You might check your fuel pressure.