Engine dies like key was turned off

[Ron H]

Yeah, it DOES destroy the confidence of driving down the highway worry-free when something like this happens…then sitting stone dead on the side of the road having no clue wtf just happened. Kind of the same thing with my electronic ignition…bad ballast, yep has happened. So keep a spare. Then one time a no start out of the blue. Traced it to a bad ECU…keep an extra one of those in the trunk now too. Over the 20 years since I put in the elect ignition two/three occasions – guess can’t really complain.

One thing I’ve become wary of - never trust an electrical connection’s integrity by – sight alone..

 

[68-500]

I have a feeling you have two things going on. Next time it wont crank jump the starter relay and if it cranks definitely something in the crank circuit back from the relay. Dies? Have to troubleshoot it when it happens.

I was thinking the same. Maybe neutral safety circuit problem and Ignition coil.

 

[Ray70Chrg]

I think you have 2 separate problems. I recently went thru the same engine running and suddenly shuts down problem like the ignition key was turned off. 3 times within 5 minutes. It would start right up again. Was able to get it home. Only thing I found was the 8 pin ignition connecter under the steering column was slightly askew so I used a ty wrap to hold closed and have not had the problem again. Have driven about 100 miles since. This probably not your start problem. Hope this helps.

 

[turbine68rt]

Had a very similar symptom with mine over the summer. Turned out to be a poor connection in the main engine harness that ran to the battery side of the alternator (terminal P). After cutting out 3 times, got it back to the hotel parking lot at Carlisle, dropped the bulkhead down to the brake pedal, removed the female conector and cleaned out the plastic debris and held it while a friend reconnected the harness. Got me home with no issues. After that I replaced the entire bulkhead, along with a new main harness and female connector and haven't had a problem since then.

 

[kiwigtx]

You have a loose wire at the ballast resistor......or a bad ballast resistor.

 

[Jeff Erwin]

You have a loose wire at the ballast resistor......or a bad ballast resistor.

Ballast and ECU are built into the distributor.

 

[kiwigtx]

Ballast and ECU are built into the distributor.

OK...you have a loose wire somewhere in the ignition circuit - somewhere you might find movement in the loom.

Try moving the loom around with the engine running and see what happens.

 

[Geoff 2]

What dist, a HEI conversion?

 

[Jeff Erwin]

Latest update. I am narrowing the issue down to the ignition switch, just based on the clues and eliminating what it can't be. It's such a simple system, one RUN wire from the switch to coil and distributor. The major clue I am clinging to is the fact that the ignition switch has been exhibiting some issues over time, like wont start with the car in P, only N, but intermittent. The only way to get the engine to just shut off is to de-energize the RUN wire, at least that's my working theory. All the wiring is new and has been running error free for a year, so it can only be a loose plug or the ignition switch.

Found a new switch online for $50. Now just have to continue tearing the steering column apart to get the wiring harness out.

 

[72RoadrunnerGTX]

...like wont start with the car in P, only N, but intermittent.

There is nothing about the ignition switch having to do with the gear selector position. That would be the NSS on negative side of the starter relay primary, “G” terminal. Usually, it’s shift linkage slightly out of adjustment that causes intermittent no crank in Park.

 

[Dennis H]

While on the hunt the ignition switch was replaced during the parts changing phase. To no avail but with collateral damage. I wish you better luck.

 

[dadsbee]

Before you go tearing **** apart, run a wire directly from battery to your to your coil/distributor and see if it still dies...

 

[hunt2elk]

One thing I’ve become wary of - never trust an electrical connection’s integrity by – sight alone..

You got that right. I have found more than one bad crimp on M&H harness' over the years.

 

[ka0mek]

as

I need some expert diagnostic help on this one.

71 Charger 440x6. Runs like a top, purrs like a kitten, all that. Completely rewired the car bumper to bumper 18 months ago, everything's been flawless since then, with one exception. Occasionally the car won't turn over with the column shift in P, have to move it to N and the car will start. Doesn't happen every time. I kinda suspect I need to adjust the shift rod down at the transmission. No big.

Then last night I'm driving home and the engine dies. No sputtering, gagging, just like I had turned the key off. Everything electrical is still working, headlights etc. I pull off, put the shifter in P and the car fires right back up again. 10 minutes later the same thing happens again, engine just dies like I turned it off. This time turning the key to restart does nothing, just like it sometimes does (above). I try N, nothing. This goes on for a few minutes as I try moving the steering column, moving the shift lever etc. Eventually, 10 minutes or so, it turns over and the engine fires right up. Runs perfect all the way home, although all my trust is obviously gone.

WTF? I think it must have to do with the key start wiring somehow, then I'm thinking maybe a loose ground from the steering column to chassis.

This one has me baffled. Any thoughts?

as for as no crank in park its a linkage issue or maybe a flaky neutral safety switch it screws into the side of the trany the key switch dose not have anything to do with it s for it just stopping i would look fir a hot coil wire / ignition wire grounding some place but i know know or what to tell u on that

 

[Ron H]

You got that right. I have found more than one bad crimp on M&H harness' over the years.

Speaking of electrical gremlins, last week was following my wife (09 Sonata) noticed the left rear brake light was out. Got it home and propped a 2x4 btw the pedal and seat checking the lights and it was working. Checked the bulbs, connectors, wiring all looking fine. Car is very clean low mileage, no corrosion ills. Checked turn signals, flashers, hmm, works. Put it back together.

Driving back from my Saturday morning breakfast ritual with a few of my geezer buddys, one had followed me until he had to turn off in his direction. Got a text from him saying your left brake light is out. Well WDH? Back home, in the garage did the same with the 2x4 and brake lights working fine. Then I turned on the ignition (my wife is a stickler for having headlights on always having the switch set for this) go to the rear and the brake light is out. Pulled bulb out leaving it in its socket and ran a ground jumper to the bulb. It lights up. Pull out the bulb, re-check the socket and bulb, looks clean as can be. Seats tightly, wiped it off anyway and reset it in the socket. It works fine – now. All I can figure is the bulb wasn’t set right in its socket, it looks fine and has been in there a long time. So will see…

 

[Jeff Erwin]

There is nothing about the ignition switch having to do with the gear selector position. That would be the NSS on negative side of the starter relay primary, “G” terminal. Usually, it’s shift linkage slightly out of adjustment that causes intermittent no crank in Park.

True that. This has been an issue for some time, I do suspect the shift linkage. Pretty easy adjustment. Still doesn't explain the shut-off issue.

 

[72RoadrunnerGTX]

True that. This has been an issue for some time, I do suspect the shift linkage. Pretty easy adjustment. Still doesn't explain the shut-off issue.

Yea, separate issue for sure. As I recall you replaced the original dash harness/wiring with an aftermarket harness. Did you retain the ignition switch Molex connections at the lower column?

 

[Jeff Erwin]

Yea, separate issue for sure. As I recall you replaced the original dash harness/wiring with an aftermarket harness. Did you retain the ignition switch Molex connections at the lower column?

The connector coming out of the steering column was not replaced because it required taking the steering column apart. The original connector then mapped into the connector that came with the new harness.

First connection I checked, seems solid.

 

[Jeff Erwin]

What dist, a HEI conversion?

MSD.

 

[72RoadrunnerGTX]

The connector coming out of the steering column was not replaced because it required taking the steering column apart. The original connector then mapped into the connector that came with the new harness.

First connection I checked, seems solid.

The Molex terminals were/are a weak spot, is first thing I replace with something that can handle the actual ignition switch current loads. I have a couple of OE spare switches if in need. Fairly close by.