Idle adjustment question, Idles high or slowly stalls Options

[BillC]

I have an idle adjustment question for all you D-Jet gurus:

I can adjust the idle air screw on the throttle body so the car idles at 1600 RPM, and it will happily idle at 1600 all day long. If I turn in the screw just a little bit, like 1/4 turn, the car will slowly drop idle speed down slower and slower until it stalls. I can blip the throttle to keep it running, but it just wants to slow down and stall. This is all when the car is fully warmed up.

How do I get the car to idle steady around 1000-1200 RPM? 1600 is just too high.

Car is a '73 2.0 with factory D-Jet. I installed new Standard Products FJ67 injectors, and the fuel pressure is 29 psi. There are no leaks in the intake side, and the idle adjustment screw is about 2 turns out (so there's plenty of adjustment available in both directions). The MPS hasn't been messed with, and the ECU looks like the correct unit. All new vacuum lines, fuel lines, pump & filter, and fresh gas. New @JeffBowlsby engine and alternator wiring harnesses.

Known issues: it has the wrong CHT sensor (it's the one that's commonly available) and I think the TPS board has worn traces. I finally found the right CHT and ballast resistor, and I also have a 914Rubber replacement TPS board, and I will install both of them when I get a chance. However, I don't think either of those should keep it from idling at a reasonable RPM.

[emerygt350]

Absolutely change that to the rear facing port.

[BillC]

Update: I heard back from Ed Madak at 123Ignition, and he confirmed the distributor should be connected to the retard port at the back of the throttle body, on that timing setting.

Absolutely change that to the rear facing port.

I will change it tonight, after I get home, and will report back.

I assume you timed it with the vacuum disconnected.

Yup, timed with the vacuum hose disconnected and the port on the throttle body plugged.

What do you know about the cam?

Nothing, other than it's supposed to be a stock cam or stock profile.

What’s the status of your vacuum? What is that doing as you try to adjust the bleed? Valves properly adjusted?

Valves are properly adjusted -- I did them before reinstalling the engine in the car, which was probably only 50 miles or so ago.

No idea about the vacuum. I need to hook up a vacuum gauge and see what's going on.

Does either of your MPSs hold vacuum?

Yes, they both hold vacuum.