Plymouth dies in the middle of an intersection and won't start

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TylerW

TylerW

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As the title states, I almost had to push my car off the road today, luckily I had some momentum because of a hill.

I was sitting at a light, waiting for it to change and the engine quit, like the switch was turned off. No pops or anything, and it had been running fine up until then.

I tried to start it several times and all I got was a couple random firings, then nothing ever after.

I checked everything...the rotor turns and there's voltage at the coil and the ballast. The ballast is good. I have the factory service manual which outlines several ohm tests regarding the control box and the pickup module. Are these reliable?

I noticed the distributor still has the "rivet" holding the pickup to the plate, so it's never been changed. The other distributor has had that drilled off so the pickup can be changed without disassembly....good idea?

This is all 1973-vintage electronic ignition w/4 wire box and single ballast. Is there any advantage to using a 5-wire box and dual ballast if I have to replace some bad parts?

BTW the control box doesn't appear to have overheated and lost it's goo.

Thanks...
 
If not the ballast, I highly suspect the control module. Always Keep a cheap spare on hand too.
 
Fusable lint too, my Coronet did that at a light, like someone flipped a on/off switch. I did the Ammeter bypass, Bat post on the alt to the batt post on the starter relay, hasnt happened again, most of the system voltage goes from the alt right to the battery.

Your lights wont dim or flicker any more when at a light with the turn signals, turn signals wont slow down when your at a light with your brakes on etc.
 
rp23g7 said:
Fusable lint too, my Coronet did that at a light, like someone flipped a on/off switch. I did the Ammeter bypass, Bat post on the alt to the batt post on the starter relay, hasnt happened again, most of the system voltage goes from the alt right to the battery.

Your lights wont dim or flicker any more when at a light with the turn signals, turn signals wont slow down when your at a light with your brakes on etc.
Click to expand...

That's a great idea.
 
if im not mistaken if the link goes bad it wont turn over .will it ? i was thanking the wire comes from the alt to the link threw the firewall and to the amp meter and the back to the ignition relay i may be worng but thats my toughts on that some cars have two tho they have oe that between the amp meter and then comes back out to battery and the they have one that comes from the starter relay so guess it could be the link if it a car with two did you check for spark at the plug wires ?
 
I had that happen to me in the middle of a busy intersection once, ended up being a overheated coil. once i replaced it, i haven't had that problem since. you can usually let it cool off or keeping a spare helps.
 
if the gel is melted out the back of the ecm, there's your sign
 
That happened to my '68 GTX once. I was driving through town years ago and the engine just died. Cranked, but no firing. I looked under the hood and noticed that the coil had slipped inside the mount strap and a terminal grounded against the intake manifold. I pushed the coil back and tightened the strap and the engine kicked right over.
 
moparisbest said:
if im not mistaken if the link goes bad it wont turn over .will it ? i was thanking the wire comes from the alt to the link threw the firewall and to the amp meter and the back to the ignition relay i may be worng but thats my toughts on that some cars have two tho they have oe that between the amp meter and then comes back out to battery and the they have one that comes from the starter relay so guess it could be the link if it a car with two did you check for spark at the plug wires ?
Click to expand...

True, it didnt turn over when it happened to me, Turn the key, and nothing. wiggeling the wires at the bulkhead must have donesomething, or it just cooled off enough. I have had good luck with the bypass though.
 
TylerW said:
As the title states, I almost had to push my car off the road today, luckily I had some momentum because of a hill.

I was sitting at a light, waiting for it to change and the engine quit, like the switch was turned off. No pops or anything, and it had been running fine up until then.

I tried to start it several times and all I got was a couple random firings, then nothing ever after.

I checked everything...the rotor turns and there's voltage at the coil and the ballast. The ballast is good. I have the factory service manual which outlines several ohm tests regarding the control box and the pickup module. Are these reliable?

I noticed the distributor still has the "rivet" holding the pickup to the plate, so it's never been changed. The other distributor has had that drilled off so the pickup can be changed without disassembly....good idea?

This is all 1973-vintage electronic ignition w/4 wire box and single ballast. Is there any advantage to using a 5-wire box and dual ballast if I have to replace some bad parts?

BTW the control box doesn't appear to have overheated and lost it's goo.

Thanks...
Click to expand...


First thing I would try is bypass the ballast briefly to see if it starts. I'll bet the coil or pickup coil though. Yes check the pickup coil, unhook the 2 prong wire from the distributor, set your meter to the OHM's scale and see what you get. Should be between 375 and 900. Next set your meter to AC volts, spin the engine over enough to turn the dizzy a couple of times and you should get 1 volt AC.
 
Had same problem with my challenger.
After MUCH searching,replacing parts and head scratching it ended up being bad ammeter connections.Not the wires to the ammeter but the post connections inside.
This was a "glad I found that" situation as this could have been so close to one of those notorious ammeter caused fires.
solution...bypass the ammeter.Just bolt the two wires to one terminal and fit a volt guage.
 
Well it's fixed, and it's going to come as a bigggggggg shock to you regarding the cause....:thumbdow:

It was the damn box. 3 screws and 5 minutes later and it's allll fixed, after spending money on the tow. If I had ONLY had a spare......

The one that went bad wasn't melted out, and funny thing was, the transistor had Malaysia printed on it and the heatsink had Made in USA.

I'm curious if a low voltage problem could have contributied to it's demise. I'm losing 2 volts from the battery to the ECU, and the FSM says it has to be no more than 1v under.

I plan to do the ammeter bypass ASAP and I also added another ground strap from the ECU to the body of the car.

Thanks much for the help.
 
Couple of places to look for the voltage loss before messing with the amp gauge... Look for a rectangle connector near the rear of the right valve cover. Pull it apart and check for evidence of overheating. Then the bulkhead connections through the firewall and the harness connector from the ignition switch under the steering column.
Good luck
 
RedFish said:
Couple of places to look for the voltage loss before messing with the amp gauge... Look for a rectangle connector near the rear of the right valve cover. Pull it apart and check for evidence of overheating. Then the bulkhead connections through the firewall and the harness connector from the ignition switch under the steering column.
Good luck
Click to expand...

Thank you, I will check those. The '73 Sport has actually burned a hole in that connector over the valve cover.
 
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