I have a friend who is having a problem with the car running OK until it's fully warm and then it won't run under 4000 or so rpm's....???

Any ideas?

It's a d jet 1974 2 Liter

UNDER 4k?

Wrong cam?

Dono..

Cloged injectors? incorrectly timed? Dwell? valves? spark? cloged fuel filter? engine toast?

Dont know...

Andrew

check all the vacuum tubes. i was working on my 2.0 and forgot a vaccum tube ( i think it hooked in under the throttle body ) and fired it up. when it idled at 4000 rpm i new something was wrong.

Check the timing, the TPS, do a valve adjust to make sure everything is in tip-top tune.

I'd say an air leak. Since it happens after it gets warm it is probably a joint such as the intake manifolds to head joint or a seam on the intake plenum or some other place that can open as it gets hot. Use the carb spray with a nozzle and spray around the whole intake system and it should show up. Good luck