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Discussion Starter #1
Another hot starting issue with yet another truck. Please bear with me as I weave a tale of woe.

In 1973, I bought a new D100 Adventurer Sport with automatic and a 318-3 with trailer towing package. From day-one it had intermittent and annoying starting issues. It didn’t flood, and pumping the gas did nothing to help start, and I often had to wait until the engine was cold before it would fire.

Trips to the dealer were no help as they said everything was adjusted and operating per specs, and of course, it never failed to start when I brought it in. To top it off, mileage was terrible at 8 mpg when running easy without a load.

When the warranty expired, gas prices were high, so I decided to replace the stock intake with an Edelbrock SP-2P along with a Holley Economaster carburetor. The mileage picked up to 10, but the annoying starting problem remained.

I lived with this combination for about seventeen years while doing normal tune-ups and experimenting with various minor modifications. Yes, including fiddling with the pollution controls. The mileage went to 12, but nothing helped the starting problem.

About this time, the original starter failed as it was drawing a heavy load. I replaced it with a stock rebuilt unit. I hoped that it had been the problem all along, but no dice.

About twelve years ago, a freeze plug on the back of the engine rusted out, so I decided to do a frame-off restoration. It had logged only 80k, but had been stored outside for at least thirty years, so I went through everything. Pistons, rings, bearings, valve-job, tune-up plus a new water pump, and I modified the fuel system again with an Edelbrock Performer combination of cam, intake and carb. And yes, it has a thick gasket under the carb, but then it never does flood so I don’t think it’s perking from engine heat. I was certain the hardware changes would finally free me of the starting problem. Nope! Great performance, and it purred like a kitten, while mileage jumped to 15.

A few years later I had to replace the stock starter again, so I replaced it with a new mini-starter. It spun like a new truck, but the hot start issue remained. About that same time, the original ICM puked, so I got a new one, plus a new voltage regulator. No help.

I don’t drive it much these days but I had to replace a dead fuel pump a few months ago, and when I did, I rebuilt the Performer carb as it had the usual Ethanol crud making it run a little rough. Did it help the hot start? What do you think? I gave it another fresh tune-up, including replacing the coil. No help.

The only thing I had never replaced was the distributor, so with 91k on the clock, I bought the best one I could get…no Chinese junk, but I might as well have saved my money if I expected it to help. FWIW, I always buy the highest quality car parts that I can find. The manual says initial timing should be 2-1/2* BTDC, but I set it to 5* before and it didn’t ping. Total advance is about 34*.

Yesterday I took it in for the state inspection and almost killed the battery before it started when I left. Spun like crazy and didn’t flood.

Now, there are a couple of little things that might mean something to you expert troubleshooters.

When it finally does start, it starts the moment I release the key, but never even attempts to fire until that time. It’s as if there isn’t enough voltage to fire, or it’s not getting it from the right source. I believe that terminal should be Ign 2 on the starter switch. However, to add to the confusion, the starter switch is not even the original style, while the problem has been going on forever. When I restored the truck, I found a badly burned wire and melted splice in the column wire bundle and learned that it had been a serious problem for those years and that it had caused numerous fires. I decided to replace the old-style hardwired switch with one from a ‘79 Aspen. It physically mounts behind the dash on top of the tube and has a plug-in switch mechanically attached to the ignition switch actuated by a rod. I used a new harness and a new switch. Everything else worked fine, but not the starting issue.

Another possible hint. When it finally started at the inspection station, I drove off and realized that all the dash electrical functions were dead. When I got home, as I turned the switch off, the dash returned to normal and I couldn’t get it to fail again. All the fuses are good.

At this point, I suspect I have a switch with bad contacts, but I can’t see how that might contribute to forty-seven-year-old starting problem. In the meantime, since it always fires immediately when cold, I guess I’ll just live with it and carry a book to read while I wait for it to cool.
'73 Adventurer Sport.jpg
new master cylinder.jpg
 

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I had a 73 Polara that had the same issue, Gary. I replaced the control module and that cured mine. Have you EVER replaced it? If not, make sure it has the exact same # of pins. I got my first one from Western Auto and it had one less pin. When I questioned the parts guy, he told me it wouldn't matter, the extra pin was just a ground. I put it in and it failed to start. Put the old one in and it started. He didn't have one with the right pin count. I went to Autozone and got one and it was EXACTLY like the OEM module. Installed it and car was good from then on. This was back in 1994 and I've had two brain surgeries and bacterial meningitis since then, so the old memory is fuzzy. My module either had 4 or 5 pins and the Western Auto one had either 3 or 4. I don't recall which was correct. But, you will know what I'm talking about when you remove the connector and count your pins. BTW, that's a great looking truck. Here's the AZ link. https://www.autozone.com/ignition-t...ng=search&isIgnoreVehicle=false&model=control
Looks like the extra pin is for cruise? Polara didn't have cruise, but I'm pretty sure it was the 5 pin. Of course, the slightly more expensive one! LOL
 

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A five pin Mopar Electronic Ignition module is used on a system with a dual ballast resistor. In this case, the ballast resistor has a start and a run side.
The 4 pin module is designed for a single ballast resistor as only the run side is used (start gets full volume).

A 4 pin Mopar module is supposed to work in any car, whether it had a 5 or 4 pin module originally. If it didn't, the after market box must not be made the same as the Mopar one.
 

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Discussion Starter #4
I just verified the module that replaced the original Mopar unit is a five-pin Standard, and the ballast is 4-pin..


The ballast is the third one. The original failed maybe thirty years ago, and its replacement was itself replaced during the frame-off re-build, even though it was still functional.
 

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The symptom of a failing ballast resistor is the opposite. It will fire while cranking the engine, then die as the key is released to 'Run'.
The bulkhead connector at the firewall was troublesome in this era. Disconnect it and look for tarnish/corrosion on the terminals and melted plastic (heat from a high resistance connection). This could also cause the instrument cluster not working problem.
Bulkhead connector problems could be very intermittent. Sometimes tugging or wiggling the underhood harness would temporarily get things working again.
 

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Discussion Starter #7
Dave, yes, Mopar bulkhead connectors always seem to be a problem and I've had my share. Though I try to inspect and keep them clean, the dash failure could certaijnly be due to a dirty or corroded connector, however, the starting problem has been there since May of 1973 so I doubt it's the cause, but I will check it.

FWIW, old connectors are so unreliable that on my current '56 Plymouth project car I rewired and upgraded all the wire bundles, added several fused circuits, and replaced the bulkhead connectors with one modern environmentally sealed connector.

Imperial Crown, I've had several ballast resistors fail on my old Mopars, so I'm familiar with their failure symptoms. I was just clarifying that the wiring and the parts in that area were the stock configuration.
 

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Hi GaryS -

* Have you tested the pick up unit inside the distributor? A bad pick up unit could cause intermittent hard starting or no starting. This has happened to me in the past.

* Is the distributor reluctor gap set to .006“ to .008”? This needs to be adjusted with a brass feeler guage.

* Have you tested the ignition coil and ignition switch?

* Is the electronic ignition control module grounded? This can cause starting problems. Some people run a separate wire from the module to a ground source.

* You may have a bad electronic ignition control module which could be giving you intermittent starting problems. The best aftermarket box I am aware of is the Standard Products LX 101 (made in the USA). I don’t know if you can still get an OEM box from Chrysler.

Hope this helps. Good luck!
 

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Discussion Starter #9
Wheeler, both the coil and distributor are brand new. I didn't measure the gap, but when I give the shaft a spin, you can feel it "kiss" at every point. That's a pretty good indication, and the hot start problem after they were installed is the same as before. The coil is a new Standard part and the distributor was made in the Philippines...the best one I could find online.

The module is a Standard LX100, the five pin version. I didn't measure the module ground, but It's installed with two sheet metal screws with internal tooth star washers and was removed and reinstalled recently, so the washer contact points are fresh. I will check the ground of the inner fender to the chassis, but again, nothing I've done in forty seven years has noticeably affected the symptoms . FWIW, when the original module failed, I temporarily installed a MP orange box until the new part arrived. I only drove it a few times with that module, but didn't notice if there was a change when starting.

In my original post, I explained the ignition switch modification, but the problem was the same with both switches.

It's frustrating! I've about decided to replace the wires from the ballast resistor to the coil, ignition module and ignition switch to see if one wire might have a break concealed by the insulation. That could be affected by heat as the wire expanded and cooled.

I once had an old Plymouth that left me stranded on the road at 3 am as I was on the way to the airport to fly to Germany. My friend had it towed to the Chrysler garage and they found one of the points would not conduct. The mechanic said it was the first time he had ever seen that happen. I also had a battery cable corrode inside the jacket and nothing could be seen from the outside. Maybe I was chosen to have yet another one-of-a-kind electrical failure.
 

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Have you replaced the neutral safety switch? The common hot start problem with it was that it wouldn't crank, but maybe yours is different. Also, have you tried instant starting fluid when it doesn't fire immediately? If it helps, I'd suspect a fuel issue, but if not, it's probably electrical.
 

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Discussion Starter #11
With the mini-starter, it spins like a top all the time and I recently started to carry a can of starting fluid with me. It won't even try to fire if I spray it when the engine is warm.
 
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