Troubleshooting Ignition Control Module ???

[nkemp]

Original problem solved (user error). But it still begs the question about troubleshooting an Ignition Control Module/unit.

[David T]

Original problem solved (user error). But it still begs the question about troubleshooting an Ignition Control Module/unit.

You rule out all other possibilities before assuming the ECU is at fault. Refer to M:01:03-:04 in the Workshop Manual. Just an FYI, it is rare to see an ignition ECU fail.
David Teitelbaum

[DMCMW Dave]

Original problem solved (user error). But it still begs the question about troubleshooting an Ignition Control Module/unit.

Replace with a test unit. The car still won't run, then you put the original back in and figure out the problem.

But really, if everything else tests good (resistance/continuity to the pickup coil, power and ground) the only real, final, test is a substitute part.

[nkemp]

A replacement/test unit sounds like the best way.

I think I have my intermittent dying problem solved. But I now drive the car with a bit of concern and worry. Recently I saw this elsewhere... "A failing ignition control module can be a real headache at times. It can produce a wide range of engine performance problems, including preventing the engine from starting or stalling the engine as you speed down the road, just to let you resume your driving a few minutes later, as if nothing had happened."

I think my problem was inertia switch or ground related.

Thanks for the input,
Nick

[dmc6960]

Dont forget Nick that there ARE a small handful of local DeLoreans active and driving. If you ever needed to borrow a part I could easily stop by sometime.

[AugustneverEnds]

Here I am dusting off older threads again but I am starting to think my ignition ECU is dead. I have been troubleshooting an ignition issue for a month now (working slowly and on several projects) and I have run out of anything else to try. Besides being the last item on the list I read here on the forum that if the tach doesn't move when cranking the ignition ECU becomes a suspect. I tested the plug to the ignition module with an icepick light and it is getting power. Fuse 1 is good. My car is a high mileage (100k+) car so maybe the module is toast?

Would it be possible to call a vendor and perhaps put a deposit down to borrow an ECU to test? I have read some owners are using Ford or GM modules. How are Autozone or Advance with returning electrical parts? I don't want to buy one and not have it solve the problem and be stuck with it.

[mr_maxime]

Would it be possible to call a vendor and perhaps put a deposit down to borrow an ECU to test? I have read some owners are using Ford or GM modules. How are Autozone or Advance with returning electrical parts? I don't want to buy one and not have it solve the problem and be stuck with it.

I've got one. PM sent

[David T]

The best trouble shooting chart is in the Tech Manual pages 125-126. If you don't have it the most common problems are;
Not using an OEM Bosch ignition coil
Bad pick-up coil or bad connection
Low system voltage (must be higher than 11 volts!).
Bad connection on the ballast resistor, the connections get rusty.
Bad wires, cap or rotor.
The place to start is to see if you get spark out of the coil while cranking. The ECU is the LAST thing that fails. Very rare.

[nkemp]

... How are Autozone or Advance with returning electrical parts? I don't want to buy one and not have it solve the problem and be stuck with it.

Electrical parts are the parts many places won't take back if installed. Too easy to ruin them if there is some other electrical failure.

[AugustneverEnds]

The best trouble shooting chart is in the Tech Manual pages 125-126. If you don't have it the most common problems are;
Not using an OEM Bosch ignition coil
Bad pick-up coil or bad connection
Low system voltage (must be higher than 11 volts!).
Bad connection on the ballast resistor, the connections get rusty.
Bad wires, cap or rotor.
The place to start is to see if you get spark out of the coil while cranking. The ECU is the LAST thing that fails. Very rare.

Replaced the original coil in 2017 with an OEM Bosch coil. It's getting power and measuring .6 Ohms primary resistance
Bought a new battery a few weeks ago, reading 12.5 Volts
Replaced the terminals on the ballast resistor
Wires, cap and rotor replaced in 2017 (Bougicord and whatever PJ Grady sent to me),,

Hmmm pickup coil.... What test would rule that out? Like I stated earlier, I saw no spark on one of the plugs and the tach is not moving