'72 145E

I can't get a steady idle. Well, I can, depending on when I clutch. Coming to a stop, if I put the pedal down above 1500rpm the car will often stick with a high idle, 1200-1300rpm. If I engage the clutch a little, it will come down and stick at around 600rpm. If I adjust the idle screw, I can get the lower idle up to around 800rpm, but then the higher idle is obnoxious, around 1500rpm or higher.

Things I've done so far, assuming it was a vacuum leak:

Replaced most of the vacuum hose coming off the intake manifold. Those that I haven't are ports that have been plugged with the purpose designed vacuum plugs you can get at auto parts stores. Those ports are for the vacuum retard on the distributor, and the two for the cold idle valve. Well, except the valve cover hose. I just didn't replace that because it looked fine.

I had to replace my exhaust manifold anyway (it came off in 2 pieces), so I replaced the manifold gasket. Visually inspected the intake, no cracks.

Re-mounted the injectors to the head (found leaks with carb cleaner), and tested the seals with carb cleaner.


Assuming it was a distributor or recently installed electronic ignition(the crane system) issue:

Originally a -021 distributor car, I used a -033 distributor when I installed the electronic ignition. I don't know what the difference was, but I switched back to the -021 distributor and installed the EI in that one. The car felt stronger, but the idle still moves around. Re-set the pickup for the EI inside the distributor using the "move it until the test light on the ignition module lights up" method.

So, tonight for the drive home I'm going to re-connect the vacuum spark retard. After that, I'm not sure where I'll be checking next. Any ideas?