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Discussion Starter · #1 ·
Looking for some help with the ignition on my 1980 C-7 304 V8. I’ve owned the Jeep about five months and had no issues with it cranking or firing up. I pulled the dash apart as I’m swapping gauges and putting in a new dash panel. With all gauges removed and no other under-hood wiring changed, the starter will turn just fine but won’t fire up.

I’ve replaced the ignition control module (which looked like death) and the coil. I haven’t done anything with the distributor or cap yet. Some wires to/from the ICM are cut (see pics).

I’m at a loss on what could be going on. My next step is likely to hook back up all gauges because all I can figure is that someone rewired something and I broke a circuit somewhere along the way pulling the gauges.

Here are some pics but I’m stumped and looking for suggestions from the wiring experts out there. I’ve considered the Painless rewire to clean up the existing wiring but I’m not sure that will help the non-firing ignition.
 

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Just to give you a little confidence

See if it will bust off by doing this.

If it will start this way, we might have a better idea

on what to track down

Try not to add any more factors in until you return with these results

I'm showing a 258---surely you can transfer this to the 304 setup!

Positive battery to positive coil----crank it up

Does it start?

Kill it by removing the temporary jumper wire.

----JEEPFELLER
 

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Discussion Starter · #4 · (Edited)
Just to give you a little confidence

See if it will bust off by doing this.

If it will start this way, we might have a better idea

on what to track down

Try not to add any more factors in until you return with these results

I'm showing a 258---surely you can transfer this to the 304 setup!

Positive battery to positive coil----crank it up

Does it start?

Kill it by removing the temporary jumper wire.

----JEEPFELLER
I tried this a couple of days ago with no success. This is the only thing I've tried at this point so still open to suggestions.
 

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You have an ICm with two plugs.

The 2 way plug carriees a Red wire which is live in run and Start. The White wire is live in Start only (it will spark with it disconnected, it is just a signal to retard the spark in Start). They look connected but you could test them for electricity.

The 4 way plug is the one which goes to the distributor and coil. you seem to have multiple cut wires. You also have 4 wires in and 5 wires out, which is unusual. The yellow wire does not look at home.

The light green wire goes to the coil negative and is the switching wire. If your module was working that wire would be showing an intermittent ground in time with the engine.

The other 3 wires go to the distributor. The black is a ground, the ground for the module, it grounds through the distributor body. Without this in place, your module is not working. the remaining two are purple and orange. Those are the sensor wires, which go alongside the ground wire to the distributor and then connect to the sensor inside.

As it is not connected I suspect that, if you pop the distributor cap, you are going to find the distributor has been swapped out for an older points type and there is only a wire from the negative on the coil going to the distributor. Then you can spend some time trying to get the points set up.
 

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Discussion Starter · #9 ·
OK

How did this work out?


----JEEPFELLER
How many wires going to your distributor? Kinda looks like those cut wires at the ICM would be the ones feeding the distributor originally.
Looking at the FSM, that was my thought too. There only appears to be one wire connected to the distributor (on the bottom) and that concerned me and led me to believe someone had bypassed the ICM. Is there a way to hook that back up?
 

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Discussion Starter · #11 ·
Factory tach? Amc ran the coil and icm power through the tach, so if you have taken out the factory tach, it will not fire.
Yes, factory tach. I did reconnect the the tach and tried cranking but didn't have any luck. However I didn't connect what appeared to be illumination wire so I can try that.
 

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Discussion Starter · #12 ·
As it is not connected I suspect that, if you pop the distributor cap, you are going to find the distributor has been swapped out for an older points type and there is only a wire from the negative on the coil going to the distributor. Then you can spend some time trying to get the points set up.
Yes, you're correct in that there only appears to be a wire from negative coil to the bottom of the distributor. I'm not overly proficient on checking the distributor - what am I looking for to get everything lined up? Would I be better off replacing? Thanks!
 

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First thing is to take off the distributor cap and take a photo. From that we can guide you a little better. We need to know what you are dealing with.
 

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Discussion Starter · #14 ·
First thing is to take off the distributor cap and take a photo. From that we can guide you a little better. We need to know what you are dealing with.
Here is the distributor with the cap removed. The red wire is connected to the (-) side of the coil.

To rule out the tach comment, I reconnected all wires and tried cranking. The engine turns over but doesn't fire up.
 

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That is a fam dancy points distributor that you have there, that ICM is not doing anything but going along for the ride. You need 12v to the + side of the coil and that is it to make that thing run. If 12v to the positive side of the coil doesn't make it start, then there is a chance that you left power on to the coil and points/condenser for too long and may have burned one or the other out.

Should have known from this picture with the window in the side of the distributor cap to adjust the dwell while the engine is running.

 

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Discussion Starter · #16 · (Edited)
That is a fam dancy points distributor that you have there, that ICM is not doing anything but going along for the ride. You need 12v to the + side of the coil and that is it to make that thing run. If 12v to the positive side of the coil doesn't make it start, then there is a chance that you left power on to the coil and points/condenser for too long and may have burned one or the other out.

Should have known from this picture with the window in the side of the distributor cap to adjust the dwell while the engine is running.
Appreciate the response. I tried the (+) from battery to (+) coil with no success. I replaced the coil during this process so it's brand new. I haven't tried jumping from battery to the NEW coil though. So if the coil jump doesn't work, are you thinking I need to replace the distributor?
@BagusJeep -- any thoughts?
 

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@tabosco23, going off what @BagusJeep has been saying, if the points and condenser did burn up, you can replace those two items alone. I would not replace the distributor at this time. If the distributor hold down is loosened and the distributor housing is allowed to move, even a couple of degrees, you have a whole new issue of the ignition timing being off.

To replace the points, you will need feeler gauges to gap them correctly. If you haven't done this before, definitely check You Tube from some direction!
 

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I would think about updating to an HEI style distributor. If you are just going to replace the points, I would make sure that all of the weights move freely under the rotor while you have everything taken apart. Also it would be best to have a dwell meter and adjust correctly for dwell rather than just set the base point gap. You will need the specs for an early 70's 304 to make the correct distributor adjustments.
 

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Discussion Starter · #19 · (Edited)
@tabosco23, going off what @BagusJeep has been saying, if the points and condenser did burn up, you can replace those two items alone. I would not replace the distributor at this time. If the distributor hold down is loosened and the distributor housing is allowed to move, even a couple of degrees, you have a whole new issue of the ignition timing being off.

To replace the points, you will need feeler gauges to gap them correctly. If you haven't done this before, definitely check You Tube from some direction!
Is there any way to determine if the points and condenser have burned up prior to replacing them? The distributor housing itself is firm and there is no play on the shaft.

I would think about updating to an HEI style distributor. If you are just going to replace the points, I would make sure that all of the weights move freely under the rotor while you have everything taken apart. Also it would be best to have a dwell meter and adjust correctly for dwell rather than just set the base point gap. You will need the specs for an early 70's 304 to make the correct distributor adjustments.
Thanks, I'll give this a look too. Regarding the HEI distributor, I've read about them eating up the cam, specifically on the 304. Is there any truth to this that you guys are aware of?

I really appreciate the guidance here. Most of my experience on Jeeps has been TJs and later so I'm swimming in uncharted territory for me.
 

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I just finished the hei distributor swap on my 77 304. Yes if you buy a cheap hei, it may have a harder gear than is on your cam. I bought a high quality distributor but still swapped out the distributor gear out of the old one because it was in good shape.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
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