'73 1.7L won't hold idle Options

[rettigdw914]

Long time reader, first time poster here. If it wasn't for all of the great info on this site, I wouldn't have come half as far as I have on this project.

The problem I am having is at 60degF. ambient, cold engine, the car starts, jumps to 2000rpm for about 5seconds, then sputters and dies. It is very repeatable.

Does this sound like a vacuum leak or ignition problems or other?


Parts replaced/checked:
Rebuilt fuel pump(30psi solid),
Injectors flow tested and ultrasonically cleaned(4ml for 10sec crank)
Rebuilt MPS from Bret, also used another Bosch original.
Used two different ECMs
TPS calibrated
All electrical loads to ECU resistance checked per pbanders site.

All Vacuum lines replaced, not all German hose but has good fit
Injector seals replaced
Intake runner gaskets and hose to plenum replaced
Checked cork gasket on oil fill cap and is old but sealing

Rebuilt distributor
New points,condenser,cap,rotor,coil, wires,plugs(.024")
Dwell is 42deg., out of spec. but should still run. right?
Timing set to 27 deg bef. TDC, but I have been moving the dizzy around.
Valves checked, OK

I might try the carb cleaner trick to check for vacuum leaks but any other ideas are appreciated and welcomed.

Things not replaced are: TPS gasket, Cold start seal?, AAR(it is open, not sure if closes)

Thanks,
-Don

[r_towle]

ok,
You are getting an initial blast of fuel, and the timing is wrong.

So, on the timing, get the points set correctly, your dwell it wrong.
Show me the distributor position in a picture from the passenger side, stand back so I can see the fan shroud, and the dizzy in position.
We can get you pretty close to properly timed just by looking.

So,
Fuel.
Have you tested it while running?
Take out one injector, put it in a glass jar, and start the car.
I want to see you find fuel when the car is running versus when you are cranking it.
The ECU behaves different when you crank the starter versus run the car .
It sounds like you get the initial shot of fuel from the cold start injector, and possibly the main injectors, but when you put the key in the run position, all fuel is shut off.

You need to also trace the fuel circuit, check all the relays and fuses, and check for grounding in that curcuit.

Try this.
Unplug the fuel pump (at the fuel pump)
Run two temporary wires directly to the battery, do a nice job so they do not vibrate off the pump.
You can (when you are ready) run the pump nonstop, go and start the car, then when you shut it off, just unhook the pump from the battery.

This test will tell you if the fuel circuit needs to be closely examined and look for the issue in the electric side of the fuel deliver system.

If it behaves the same way, I am still thinking that the hoses are wrong, or kinked.
You can still pressurize the system and use the cold start if you have connected the hoses wrong on the fuel pump, or in the engine bay.

Rich