LH 2.0 w/ Breakerless Ignition...Confusion

[Souped]

Hey y'all,

I have an 83 with 2.0 that I'd like to switch from the dead Chrysler ignition to the CIS era breakerless. I'm not amazing with wiring, so I think I've made it as far as I can with old threads and wiring diagrams. I am replacing the whole ignition, so there's no weird mix and match. Green book wiring diagram shows 4 wires from the breakerless ignition box, but there are 6 poles. The diagram I'm using is for a 1979.

From the breakerless box I have:

1. 2 pole distrutor plug - that's easy enough

2. 2 pole with...
...blue - run to blue wire on dash harness from fuse 11
...blue jumper - run to ballast resistor input
...brown - Not 100% here. Found an old thread that said to run this to the connector from fuse 11, which runs to the starter solenoid in the Chrysler ignition.

3. 1 pole with 1 brown and 1 white wire. In the green book wiring diagram, it looks like both of these run to the coil negative for CIS. The old thread I found splits these, sends the brown to the ballast resistor outlet and running a jumper to the starter solenoid. The white wire would run to the "dash harness tach drive (grey)". Also mentions jumpering this connection to the "engine harness connection" under the crank pulley, but I'm not sure what that is. Also mentions running another ground from this point other than the ground from the ignition box. I'm confused by this last part because I don't see this on the fuel or ignition wiring diagrams.

In the green book LH wiring diagram. It looks like the ignition signal goes from the coil negative to ECU pin 1 and grounds at pin 5. This is also the only grey wire on the diagram. Is there any reason I can't keep the existing wire running from the coil negative to ECU and plug the white/brown connector to the coil negative, where it looks like it would run on a CIS car? Would the difference in resistance measurements between the LH and CIS coils have anything to do with this?

I'm also confused about running the brown wire from the single pole plug to the ballast resistor outlet. My wiring diagram doesn't show this wire at all. It shows 2 wires from the ballast resistor outlet, one to the starter solenoid and one to the coil positive.

 

[bobxyz]

I'm not 100% sure, but to me it looks like the Chrysler box pin 8 wire jumps over the pin 1 wire in the Greenbook diagram - the diagram is pretty fuzzy, but this would make sense too from an electronics design standpoint that pin 1 and pin 8 are two different signals. Connecting the coil wire to the ECU might fry the ECU, I don't know. This could be a deal breaker.



For the rest of the wiring, here's pictures of a 1980 and 1985 Greenbooks. The '85 has the extra wiring to bypass the ballast resistor (supplying full +Vbattery) during cranking. Does this help with your wiring questions?

 

[Souped]

Maybe my diagram showing the ECU getting signal from the coil is more...metaphorical.

If the ECU is getting signal from pin 8 on the Chrysler box, do you know what the dotted grey wire from the coil negative is? Dash tach?

Edit: My ignition diagram doesn't even show a pin 8 on the box. It's a B23F diagram, not a b230.

 

[bobxyz]

Can you post your '83 wiring diagram for the ECU? I don't have a '83 greenbook.

If the "-" pin on the coil currently goes to the ECU, then keeping that connection with the breakerless ignition is fine. (I'm not good when it comes to the differences between LH2.0, LH2.1, LH2.2 and what years/models they were on originally.) The dotted line off the coil "-" terminal is for an optional tachometer.

 

[Souped]

I'm going to have to figure out how to do that, last time I was on this forum regularly I used photobucket. Much has changed...

Here is Dave Barton's diagram, which I just found and is much clearer than the greenbook scans. Page 3 shows that there is no pin 8 signal and the tach signal runs from pin 1 to the negative coil. Dave also confirmed that the LH 2.0 box gets its tach signal directly from the coil. This must have changed with LH 2.2. The greenbook diagram I was looking at showed this unlabeled as far as function and wire color, so I wasn't really sure.

https://www.davebarton.com/pdf/Harness_LH-2.0_240PinFunctions2021.pdf

 

[Souped]

Follow up question:

IPD lists a Beru coil with 3.3 ohm primary resistance as a replacement for cars with breakerless ignition. OEM spec is ~1.9 ohm. Does anyone know if this coil has an internal ballast resistor? Anyone run it without issue?

I could not find the part number listed ( ZS 172) in the Beru catalog to get specs. Beru catalog lists a different number for early 240s, but only lists euro spec engines.

 

[Souped]

Follow up question:

Is the ballast resistor just for the k-jet coil?

If I installed the more common Chrysler ignition coil that does not require a resistor , could I do away with the resistor and the extra lead to the starter solenoid that delivers momentary full 12v to the coil?

 

[dl242gt]

Yes, the 3.3 ohm coil is made to be used without a ballast resistor. The 12v boost to the coil is helpful for hot starting. Main thing with breakerless is to have the total impedance correct because it's an analog system which needs proper primary resistance or it can fail. So 1.9 ohm for the coil and .9 ohms for the ballast resistor gives you 2.8 ohms which means a 3 ohm coil would work for you.

 

[Souped]

Yes, the 3.3 ohm coil is made to be used without a ballast resistor. The 12v boost to the coil is helpful for hot starting. Main thing with breakerless is to have the total impedance correct because it's an analog system which needs proper primary resistance or it can fail. So 1.9 ohm for the coil and .9 ohms for the ballast resistor gives you 2.8 ohms which means a 3 ohm coil would work for you.

Thanks David. How much wiggle room do you think there is on the coil resistance? +-10%? My Chrysler ignition coil is 1.2 ohm, so that's not going to cut it. The replacement blue Beru coil (quality name, hopefully quality part) is listed at 3, 3.3, 3.5 ohm from different sources.

I have a flooding/hard cold start problem I'm trying to figure out. Plugs are not sooty, just wet with gas. The last thing I messed with in the engine bay was the ignition, so I'm trying to check all my work.

 

[dl242gt]

Yes, the tolerance is probably 10%. I would use the 3 ohm coil if I was going to try one. Hopefully, that helps get some more powerful spark for you.