My Z was running fine for a while, then developed a fueling issue. The idle is steady at 1000 rpms and mostly smooth with the occasional pop. When cold (or at least just started) it seems able to rev and pull itself through the driveway, but pretty quickly it loses the ability to rev, sputtering if you touch the throttle, even without a load. None of this affects the ability to idle.

Per the manual, I'm going to check the fuel pressure on the rail to see if the pump or regulator are bad, but I won't have access to the tester for a couple of weeks. Has anyone else experienced this, and if so what are other likely causes? I was thinking airflow or throttle position (though TPS seems far fetched.)

The car is a 1975 with a rebuilt 1977 engine. (so I'm told)

Thanks

Geof

Check your fuel pressure, fuel pump, fuel regulator , injectors (clogged can be a major problem)

Is your gasoline fresh?

Check fuel injectors.