I am having a problem at full WOT when I hit the trim button.
I lose 4 volts and the motor prukes both fuel pressure and ignition. It is a 454 modified procharged fuel injected motor. I have a couple of thoughts but am looking for input. Bad fuel pump, still running the rd pump maybe the knock sensor is compensating for a lean condition or a bad trim pump pulling to many amps, Any thoughts are appreciated.

check your grounds. then look for obvious sighns of resistance electrically. discolored wire etc,,,,,, . undersized wire for the application.


good luck

After checking everything you can imagine we went back to the first thought. We replaced the alternator initially and the problem seemed to go away and came back. Replaced the alternator again and the first had a slow regulator. If it were stock I probably would never have felt it.
Thanks for your response.