Starting Issue

[67GTX440]

67 GTX was starting fine. All of a sudden, it decided it would start, but only keep running if you hold the key halfway between ignition on and start. You have to find the exact sweet spot where the car will stay running, but you do not re-engage the starter.

I assumed this had to be a problem in the ignition switch and replaced both the ignition lock and ignition switch. With the new lock and ignition switch, the car does exactly the same.

Any suggestions?

Thanks!

Don
Jacksonville, FL

 

[440roadrunner]

Might be bad ballast resistor What do you have for ignition system?

Also could be bad connection either at ignition switch connector or at bulkhead connector

 

[Dennis H]

Uh oh. For good measure, carefully remove the bulkhead connector and spray it with contact cleaner until it runs clean. Can't use too much. Reassemble. Carefully. Until it runs clean.

 

[HT413]

There are 2 circuits where the engine will get spark - run and start. Sounds to me that somehow the run circuit somewhere between the ignition switch and coil has a bad connection or the ballast resistor is bad. So it seems to me that you are somehow getting the car to run in the start circuit without engaging the starter, but this part has me scratching my head because I didn't know that was possible with a properly functioning ignition switch.

Do you have a ballast resistor? If so, the start circuit bypasses this, so perhaps it is bad which may be why it will only run on the start circuit. However, running it this way, as I understand it, may damage your coil because bypassing the ballast resistor exposes your coil to 1) full battery voltage, and 2) full current 100% of the time, so this is very bad for an OEM type MOPAR coil.

 

[PP1RT]

X3 on the ballast resistor. Always carry a spare in the glove box too. And some tools to change it.

 

[paulajennings]

Ballast resistor always keep a spare

 

[67GTX440]

I forgot to mention the car has a Pertronix eletronic ignition. I believe I read somewhere that with some of these, leaving the car in the ignition mode can cause cause a problem. I also had to crank the car extensively recently to get it to start when my electronic fuel pump I used for priming when not recently started failed. Maybe this caused the ballast resistor to overheat

I will try replacing the ballast resistor and see if this solves the problem. When I get 3X in response to a post that gives me a warm and fuzzy feeling about that being the cause.
I see what you mean about keeping a spare. I just checked Rock Auto and these things are only $4.

 

[Pops1967GTX]

Before you chase your tail.....Do a few checks.. it could save YOU TIME & MONEY...

TRY putting 12V to coil, cranked engine, If spark, then it’s not the Pertronix----the problem is with supply voltage to the ignition system

http://www.pertronix.com/support/tips/

 

[67GTX440]

I replaced the ballast resistor for a whopping $4 investment with a two year warranty and the car did the same. Okay, looks like I now have my spare. That was not it, but all the advice in that direction got me close to the source. I checked a wirenut with four wires connected together about three inches from the ballast resistor that was connecting four wires together. Two of them to the same side of the ballast resistor and one seemed a little loose in the wirenut. I rewrapped them and put the wirenut back on and the car now starts and runs fine.

Thanks for all your help. There has got to be a better way to connect four wires under the hood than a wirenut, but this was some of the prior owners work. It probably worked fine for the past 25 years or so.

I have a new engine compartment wiring harness, but have yet to get it installed

 

[440roadrunner]

...........wirenut with four wires .............. There has got to be a better way to connect four wires under the hood than a wirenut, ...............

There is, LOL Soldering / heat shrink, proper crimp splices to name a couple

Happy you found it. Sometimes (I wasn't there) I forget to "easter egg". That is, just LOOK, and if it looks ragged and icky, that just might be the problem LOL