240 Righteous Gremlin - dying, no start

Use that test lamp to check injector pulse. You could hook one end to positive and the other end to the injector control circuit (negative).

You are getting close now that you found a no spark with a timing light. (Secondary ignition)


Put a test lamp between coil negative and ground. Blink while cranking? Yes= your circuits before the coil are are working (primary ignition)

where is the injector control circuit? is that the main ECU wiring at the fuel rail?

test light blinks during crank when rigged off the coil negative.

i drove around tonight - couldn't get her to go down. but when she does next time, I'll put my timing light on the line from the coil to distributor. would indicate if coil is firing, right?

as a broader question - would upgrading to EZK eliminate just make sense? I know these Chrysler ICUs are not desirable; and being that I may want to do +t in the future, would the EZK upgrade be a good thing to do now?

Injector pulse

Unplug an injector and BACKPROBE a lamp between the two injector terminals. Blink=injector pulse.

If you have no injector pulse AND no spark =you have a rpm signal problem, or the computers lost power.

test for that when car goes down? I tested tonight and the test lamp stayed on while backprobing the injector. my lamps are 5$ walmart ones so would that factor in for staying on vs. blinking?

i tried testing the 'dwell' to the coil with my dmm using Hz and duty cycle (+ on coil #1, - grounded to battery) - and both were erratic. Hz would jump around and rose steadily from 25Hz to like 100Hz. Duty Cycle would flash '98.6% and then 0. Then I'd take the probe off and try again and I'd get 57%, etc. My meter is working otherwise so these may indicate a problem with the pulses from the ICU to the coil?? the car was running during this test.

confirmed today that when she goes down, the coil is NOT firing. jiggled the harness connector at the ICU box and she started. so there's the problem.

What is the best solution? move to EZK?

Just throw the whole car away bro... nah, I’m playing. I had similar issues on my ‘88 244 and if what you’re attempting at now doesn’t solve it either, here are some things I did on mine that fixed the issue. Replaced spark plugs, cleaned out both air sensors, unplugged and cleaned all my grounds, replaced all my fuses with new IPD ones (coated with dielectric grease).

Also, does rain affect how often it happens? Mine would usually go haywire when it rained.