Automatic stalls in reverse.

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I bought my car from someone who didn't seem to know much. The car would run but stall when going into gear. If you increased the idle you could hold the brake and get it to clunk in and go. The previous owner said an old Mopar guy told him it had a vacuum issue... I was skeptical as well. While tracking down the issue that was the first thing I discovered. After tracking down vacuum, carb linkages, bad electrical connections; which were many. I swapped the battery, starter relay, ballast resistor.. I had the transmission and converter rebuilt, which it really did need as 3rd gear was completely gone and the converter was completely shot. I had a shift kit put in and am happy with the results, but I still had starting and stalling problems which may have been related to this, I thought neutral saftey switch but it turned out to be the switch connection. Someone, including myself and the transmission guy should have picked up as it was wrapped in half a roll of electrical tape.
Even though a bunch of issues may or may not have been a factor I wouldn't go replacing that booster or neutral safety switch just yet and keep looking.

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Mojoe9955 said:
I bought my car from someone who didn't seem to know much. The car would run but stall when going into gear. If you increased the idle you could hold the brake and get it to clunk in and go. The previous owner said an old Mopar guy told him it had a vacuum issue... I was skeptical as well. While tracking down the issue that was the first thing I discovered. After tracking down vacuum, carb linkages, bad electrical connection which were many. I swapped the battery, starter relay, ballast resistor.. I had the transmission and converter Which it really did need as 3rd gear was completely gone and the converter was completely shot. I had a shift kit put in and am happy with the results, but I still had starting and stalling problems which may have been related to this which if someone, including myself and the transmission guy should have picked up as it was wrapped in half a roll of electrical tape.
Even though a bunch of issues may or may not have been a factor I wouldn't go replacing that booster or neutral safety switch just yet and keep looking.

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Being that you pretty much almost exactly summed up my problem I will start looking again. What you pictured above I’m assuming is the NSS? On mine, there is an obvious short on of the three wires, looks melted, it’s also above the engine before it travels down to the tranny. Maybe this wire just isn’t even sending current, or maybe to little. I will clean that up and test.

The previous owner for mine was also very un-knowledgeable. They painted the 360 and 727 blue together, and they also painted the male prongs on the NSS… I have already cleaned that up.
 
ratty dart 340 said:
Being that you pretty much almost exactly summed up my problem I will start looking again. What you pictured above I’m assuming is the NSS? On mine, there is an obvious short on of the three wires, looks melted, it’s also above the engine before it travels down to the tranny. Maybe this wire just isn’t even sending current, or maybe to little. I will clean that up and test.

The previous owner for mine was also very un-knowledgeable. They painted the 360 and 727 blue together, and they also painted the male prongs on the NSS… I have already cleaned that up.
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Not the switch it is the connection to the switch, I got a new one from Napa. Part of the harness goes thru the wiper harness. The black and black with the white tracer plugs into a tail on the wiper harness and the yellow with brown tracer goes to the starter relay. In the engine bay I found the the connection that plugs into the wiper harness missing with yellow /brown going to the starter relay and black going to a screw on the inner fender, I guess to ground it and bypass the switch, as it would start, in reverse and drive. The black/white was just hanging loose. There is also a purple wire that is in the mix that goes to the back to rear harness for the back up lights. The diagram is for a 72 Dart, but I followed it for my 70 Duster and hopefully fixed all of the many wiring issues I had...knock on wood. It was pretty bad as there were lots of bogus connections wrapped in sticky black tape and then everything and mean everything, except motor was all painted black...

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Mojoe9955 said:
Not the switch it is the connection to the switch, I got a new one from Napa. Part of the harness goes thru the wiper harness. The black and black with the white tracer plugs into a tail on the wiper harness and the yellow with brown tracer goes to the starter relay. In the engine bay I found the the connection that plugs into the wiper harness missing with yellow /brown going to the starter relay and black going to a screw on the inner fender, I guess to ground it and bypass the switch, as it would start, in reverse and drive. The black/white was just hanging loose. There is also a purple wire that is in the mix that goes to the back to rear harness for the back up lights. The diagram is for a 72 Dart, but I followed it for my 70 Duster and hopefully fixed all of the many wiring issues I had...knock on wood. It was pretty bad as there were lots of bogus connections wrapped in sticky black tape and then everything and mean everything, except motor was all painted black...

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Yea that’s what I meant. So you got the wires leading to the NSS from Napa?
 
Mojoe9955 said:
Yes, the part number is ECH EC187 I think it was around $45, but I think you can get it cheaper if you shop around.
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Ok cool thank you. Could a possible method of troubleshooting be to Hotwire the coil straight to 12 volts, then change gear and see if it stalls? If it does then the problem isn’t electrical. But if it fixed it, it is electrical?
 
ratty dart 340 said:
Ok cool thank you. Could a possible method of troubleshooting be to Hotwire the coil straight to 12 volts, then change gear and see if it stalls? If it does then the problem isn’t electrical. But if it fixed it, it is electrical?
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Im really not sure on that one. The car when I bought whenever I put it in to any gear it would stall. All the vacuum lines were a mess. It came with a new Edelbrock carb that was put on to hopefully cure the problem, but it did not have the Mopar adapter to correctly work the throttle and transmission kick down linkage. I had one in my shop and put that on adjusted the the a carb and transmission linkage according the service manual, set the idle with a vacuum gauge, and even adjusted the timing some all of which improved it enough to drive it some and make it to the transmission shop. I didn't really start having the electrical problem until after the rebuild and I drove it some. If it starts and you can drive it, but still stalls I would keep looking for some like I just described. Honestly I wouldn't take my advice because even though I've been fixing stuff my whole life, starting with a bicycle when I was a kid, it's really not any specific knowledge but an accumulation of such forgotten and remembered over the years. Recently though the solutions to the problems I've been having I found by reading a few hundred posts on sites like A Bodies only.
 
Does it happen immediately when put in gear or does it slowly die? What cam do you have?
 
Ceedawg said:
Does it happen immediately when put in gear or does it slowly die? What cam do you have?
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it pretty much slowly dies after releasing the brake pedal from the floor. As the the break pedal lifts back up it dies.

Not sure what cam, the previous owner said he did put a mild cam.
 
ratty dart 340 said:
it pretty much slowly dies after releasing the brake pedal from the floor. As the the break pedal lifts back up it dies.

Not sure what cam, the previous owner said he did put a mild cam.
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Sounds like idle circuits in the carb, to lean to keep running. If pushing the gas down a little while holding brake and it stays running that’s your problem, nothing electrical. If distributor is stock make sure it’s 10 degrees btdc in neutral, advance hose disconnected. One other thing to try, while running in neutral squirt carb cleaner around carb base gasket and edge of manifold. If the idle increased you got a vacumm leak. Carb could be so far out if adjustment it’s won’t idle correct. But do the other stuff first then to next test.
 
Ceedawg said:
Sounds like idle circuits in the carb, to lean to keep running. If pushing the gas down a little while holding brake and it stays running that’s your problem, nothing electrical. If distributor is stock make sure it’s 10 degrees btdc in neutral, advance hose disconnected
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That’s a very good thought and makes sense. However, the carb if anything, is too rich right now.
 
Ceedawg said:
Almost the same affect
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Welp. I cleaned up some more shorts and faulty wiring. I un-plugged the vaccum hose going to the brake booster from the intake and capped it off. Tried it and it still died. Then did some More testing and plugged the hose back into the booster, and now the problem went away. Very confused but somehow it fixed the issue.
 
ratty dart 340 said:
Welp. I cleaned up some more shorts and faulty wiring. I un-plugged the vaccum hose going to the brake booster from the intake and capped it off. Tried it and it still died. Then did some More testing and plugged the hose back into the booster, and now the problem went away. Very confused but somehow it fixed the issue.
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They will drive you mad some days, let’s hope it’s fixed
 
I always advance timing for highest idle; but at the far retard end of that range. You can move the distributor a little and the idle will not change much from that high point. Try it with the vacuum advance hooked up and also with it disconnected. More importantly; with the vacuum hooked to a full vacuum source and try with a ported vacuum source. So, that's three different ways to try it; giving you three different throttle responses.
 
CudaFactHackJob said:
I always advance timing for highest idle; but at the far retard end of that range. You can move the distributor a little and the idle will not change much from that high point. Try it with the vacuum advance hooked up and also with it disconnected. More importantly; with the vacuum hooked to a full vacuum source and try with a ported vacuum source. So, that's three different ways to try it; giving you three different throttle responses.
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Interesting. The timing right now might be a degree or two off, but it’s very smooth. We are going to order a new brake booster, and a new NSS. Still unsure of how the process of plugging the main vaccum line to the brake booster, then re-attaching, would fox my issue.
 
ratty dart 340 said:
Interesting. The timing right now might be a degree or two off, but it’s very smooth. We are going to order a new brake booster, and a new NSS. Still unsure of how the process of plugging the main vaccum line to the brake booster, then re-attaching, would fox my issue.
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Check valve sticking
 
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