1968 NewYorker engine running diagnosis

[GOLDMYN]

68 New yorker original 440/auto. I was out driving the other day and all of sudden the engine died. I put the transmission in neutral while coasting and the engine restarted w/o issue. Drove the few blocks home. I shut it off and it has restarted in both neutral and park. I have noticed amp gauge bouncing Would the amp gauge be the culprit? I appreciate comments.

 

[Davea Lux]

If the amp gauge is failing, that will kill power to pretty much everything. If it is suspect, run the bypass as noted on several other posts on this website. A bouncing ammeter is common with a mechanical voltage regulator, a point set opens and closes and the gauge will jump each time this happens. There are a lot of reasons as to why an engine will die and then restart. Check your fuel filter, a clogged filter will gradually starve the engine for fuel. A failing coil can also cause the engine to die after it warms up the coil shorts out and stops working. Often, if the coil cools down, it will again function temporarily. A coil will also overheat if the ballast resistor has been improperly wired or has been bypassed. Check the voltage to the coil with the key on in the run position, you should get between 6.8 and 8 volts. Check these things and report back.

Dave

 

[413]

If it was a fuel problem it wouldn’t restart w/o issue. That 1968 amp gauge has been bouncing since new. Does it smooth out after dIrving a few minutes?

 

[1970FuryConv]

68 New yorker original 440/auto. I was out driving the other day and all of sudden the engine died. I put the transmission in neutral while coasting and the engine restarted w/o issue. Drove the few blocks home. I shut it off and it has restarted in both neutral and park. I have noticed amp gauge bouncing Would the amp gauge be the culprit? I appreciate comments.

I think an amp gauge would break and stay broken.
Since it started right back up, I also doubt it was fuel vapor lock.
I'd put a vacuum gauge on intake manifold vacuum port and check vacuum while accelerating rpm at the carb linkage. If vacuum starts to fall off, you may have a partially plugged exhaust.
An intermittent short in the wiring to and from the distributor could do it.
Keep us posted on your investigation, Ben

 

[GOLDMYN]

Thanks, I'll keep checking, I've started and let it run for long periods many times

 

[Ross Wooldridge]

Mine was doing this - it turned out that the 12V feed to the coil was shorting out against the valve cover - the insulation had been worn through by the little sheet metal tabs that hold the wire in place against the valve cover, and was cutting off the coil.

Check the wiring.

 

[GOLDMYN]

thank-you

 

[live4theking]

If/when this happens again make sure to look and see if you have power to anything else. If it's the amp meter there won't be power anywhere inside the car.

 

[GOLDMYN]

I"m updating the work I've done. I changed the point/condenser, coil, both end connections to the coil. I started the car, run 1 minute, died in the garage, w/o doing anything, when I mean it shut off, its clean cut off, no sputtering or dieseling. I restarted, ran great 5 minutes, died, restarted, ran fine, took it out for a drive (10 miles) ran great, nailed it and the car ran perfect, came home and shut it off, restarted it w/o issue, the only thing i notice different is the amp gauge shows a higher charging rate. Any thoughts? I appreciate the time.

 

[cbarge]

Do the underhood ammeter bypass.
Install an electronic voltage regulator VR706 ( I get mine from Autozone under 30 bux)
Replace ballast resistor for the sake of under 10 bux.
Double check all grounds under the hood especislly right rear head to firewall.
I also ground the negative cable end to radcore support. You can never have enough grounds.
Check wiring back of ignition switch.
It may be a bad ignition switch which is common on 68's.
Clean all bulkhead connectors.
Make sure the battery stud on alternator and starter relay are snug after doing the bypass.
I have been around 68's since I was 10 now 54.
Hope this helps.

 

[GOLDMYN]

thank-you

 

[cbarge]

Next time it dies leave key on the run position and with muliti meter or test light check for continuity at ignition switch. Red is hot black is switched power and blue powers the ignition system via ballast resistor..if I remember correctly. Somebody chime in if I am wrong since I am at work and no FSM in front of me lol.
Edit: when it does die check for power going in and out of ballast resistor.. Easier than being under the sash upside down..but may have to dive into it if no power coming out from dash going to ballast resistor blue wire.

 

[commando1]

Do the underhood ammeter bypass.
Install an electronic voltage regulator VR706 ( I get mine from Autozone under 30 bux)
Replace ballast resistor for the sake of under 10 bux.
Double check all grounds under the hood especislly right rear head to firewall.
I also ground the negative cable end to radcore support. You can never have enough grounds.
Check wiring back of ignition switch.
It may be a bad ignition switch which is common on 68's.
Clean all bulkhead connectors.
Make sure the battery stud on alternator and starter relay are snug after doing the bypass.
I have been around 68's since I was 10 now 54.
Hope this helps.

Nobody could have said it better

 

[GOLDMYN]

Next time it dies leave key on and wirh muliti meter check for continuity at ignition switch

I'm afraid this one might not work, what ever is doing this is instant, within a mico-second, I can restart w/o issue, I also would struggle (74 )getting in between the bucket seats and up under the dash, perhaps I don't have a firm grasp on the directions.

 

[commando1]

Long shot but WTH...
My 67 Newport drove me batshit with the exact same issues as. As if God was screwing with me with an on-off switch.
It was the Fusible Link. Everybody says a fusible link can't work intermently but I always show everybody wrong

 

[Davea Lux]

Your coil could also have a short that kills the spark as the coil warms up.

Dave

 

[PH27L7]

Hi Mike, car’s looking sharp! Rather than throw random parts at an electrical problem I like to diagnose by looking at the wiring diagrams in FSM, then draw a simplified schematic to easily test.

Intermittent problems can be hard to troubleshoot, you have to methodically work down the circuit to pinpoint. In your case, I would start by connecting a test lead at the ballast resistor with the single wire to a voltmeter and good ground, it should read full battery voltage when running. If it drops when the car dies, you know for sure there’s a problem somewhere between that point & the key circuit to the battery. If it doesn’t drop at all you know the problem is somewhere downstream starting with the ballast. The key voltage is also the reference voltage for the voltage regulator which controls the field current & alternator output, if it’s messed up it can cause the alternator output to be too high.

Chrysler wiring design may not have been the finest, but I’m actually not a proponent of the alternator bypass as a cure-all. It’s a great idea if you have bad wiring that you don’t want to mess with or if you’re running higher electrical loads than factory. Where you get in trouble with the factory setup is when you have corroded terminals, bad insulation, or alternator studs that are improperly torqued. If everything is up to snuff the factory setup is perfectly safe.

 

[Ross Wooldridge]

Like I asked before did you check the wire that delivers 12 volts to the coil?

My car was doing exactly the same thing - would die without notice and it's because that wire had frayed insulation and was shorting out against the valve cover intermittently. Couldn't see it and the car would run fine otherwise but then all of a sudden it would die. Next second run fine.

Check the wire to the coil.

Also the ignition switch.

 

[GOLDMYN]

Like I asked before did you check the wire that delivers 12 volts to the coil?

My car was doing exactly the same thing - would die without notice and it's because that wire had frayed insulation and was shorting out against the valve cover intermittently. Couldn't see it and the car would run fine otherwise but then all of a sudden it would die. Next second run fine.

Check the wire to the coil.

Also the ignition switch.

Thanks everyone, I didn't see any wire issues, could I just wrap over the harness portion which is already wrapped just to be safe?, I'll buy an ignition switch, Do I need the whole switch or just the housing and put the key cylinder back in, Been way too many years since I've replaced a switch, is there a small pin that has too come out. John, I'll replace the ballast resistor

 

[70bigblockdodge]

Check the connections at the ballast resistor. I have had this problem over last summer in my Challenger, till it did not restart