Hey, brand new here but I could really use some help. I have an '85 245 B230F N/A that's been experiencing some intermittent start issues for several months. When it happens, engine turns over but won't fire. Followed troubleshooting in the Bentley manual and isolated it to the ignition system. No spark at the coil, but it has 12 volts at terminal 15, and the connection at ground is good. Jumping the hall sender still doesn't spark (although it makes a noise like it should). If someone could verify for me though - the HT lead from the coil should spark to a good ground, correct? I used one of the strut tower bolts as it's clean of paint and gives a .000 resistance to ground with a DMM. The manual states to remove and ground out a spark plug and watch for spark there when jumping the hall sender, but I just don't see how that's going to work unless the distributor is lined up just right with that plug wire. That's not happening when the motor's not turning so...

I had a more car-minded buddy help me out and after he had just given the coil a good tap, it started right up again. All the connections there were clean and tight, so we replaced the coil to see if it was somehow shorting out. Put a new coil in, but it won't start again a couple hours later. Back to the drawing board, but I figure it's just got to be a loose connection somewhere. Next time, I gave the Ignition Control Unit a few light taps and sure enough, it starts right up. A couple days later and it happens again, so I just fiddle with the wires to the ICU, and it starts. The harness connection all looks fine but maybe there's some corrosion underneath there? Checking with a test light, the blue wire lights up bright, the green wire is very dim when it won't start.

I've been looking at buying a replacement wiring harness, as I've read that you're not supposed to remove the ICU connector without replacing it with a new one? Not sure why but I assume it's some sort of one-time plug. Is this right, or can I remove it to clean out the terminals without replacing it?

Has anybody else experienced anything similar to this? Your input and your time is very much appreciated.

 

the ICU connector on those Chrysler ignition control units is a pain in the butt. if you unplug it, you need to pull it straight out without rocking, and you'll probably need to use a thin pointy tool to tighten up the socket pins inside the plug before you reinsert it (use a healthy amount of electrical grease on reassembly, too).

lets see.. blue wire is... pin 2, power from the ignition switch via pin 15 of the coil... and green wire is... pin 3 + to the hall sensor (I've never heard of 'jumping' the hall sensor, its not a breaker point, its a semiconductor inductance pickup). yellow pin 5 is '0' to the hall sensor, black pin 9 is - and black pin 10 is ground, brown pin 6 is the knock sensor, orange pin 7 is the idle switch. grey (pin 1) is ignition timing pulses to the coil pin 1, while grey pin 8 is ignition timing pulses to the ECU.

 

'jumping' the hall sensor connector.

You pull that hall sendor / impulse sender connector, then jump pins B & C on the connector itself not the impulse sender plug.

It's on page 280-9 of the bently manual.

I had to do this a bunch to get mine started while tracking a no spark condition.

You have to be super careful not to break the connector on that impulse sender, as the plastic breaks very very easy.