| So I've been chasing this small gremlin in my NA Z since I bought it. When driving, the drivetrain would experience strange and irratic power loss throughout the powerband, with no ability to replicate it during any particular part of the power band. I've replaced damn near everything, and I maintained the strong feeling it had something to do with the fuel system; the symptoms seemed to coincide with the fuel pump voltage changes to some extent, although not perfectly enough to fit the diagnosis of a bad pump. I connected a fuel pressure gauge, and everything seemed fine. I drove it around the neighborhood and nothing seemed to change. Some days, it drove fine and I didn't have issues. Other days, there were moments where the car wouldn't get out of its own way; so seeing no results during this brief test wasn't surprising. I had already swapped in another NA pump, which seemed to make matters worse; I reinstalled the original one and things improved a bit. I couldn't decide if that was the major issue, or just a small player in a larger issue. Every time I messed with the fuel system, it seemed to make a noticeable difference; it usually wouldn't start to have a problem for a few days after reinstalling the pump. I decided at one point to replace the fuel pump with a known good tt fuel pump. I remembered the tt pump whined just a bit with the NA wiring and controllers, and I wanted to hear if anything was cutting out at the same time I experienced the issue. I thought, maybe it was a wiring issue. And so it was, sort of. When I went to install the tt fuel pump, I noticed something interesting. Notice in the photo (thanks to Ash) where the wire hangs down on the inside of the assembly. Those are soldered to a small, round disk that is held in place by a rivet through the top, allowing the assembly to be installed and sealed, but still giving way for the electrical connections to pass through. Well, on mine, the black and red wires were so loose that the disks were simply swiveling around in place. I took a small punch and tapped the rivet tight so it fixed the loose connection. I reinstalled everything, and suddenly the powerband is consistent and I have no strange power loss issues. At first I was quick to blame the increased fuel pressure, but in a fuel system like ours, that would only make sense if there was also an injector or other issue. Either way, I was always very careful when handling the assembly so I don't know how they became so loose. I imagine others here likely have similar issues and might not know it. 
Cheers,
JBrobst "A life spent making mistakes is not only more honorable, but more
useful than a life spent doing nothing." George Bernard Shaw |
Interesting fix for irratic hesitation/power loss issue. - 
