Ignintion causing stall while driving...help

[wsutard]

I was driving on the free way the other day, 85 degrees out, temp got to about 195. Parked, went to dinner, couple hours later I headed back out. In the middle of the freeway on ramp the engine died then came back on causing huge back fire and a buck. I was forced to continue on to the freeway. Nothing happened for another 1/4 mile. Then the engine died and came back on again, bucking, multiple times. Then it stayed on for another 500 ft.

At this point I was looking for the nearest exit, which just so happened to be up a frigging hill. I hit the exit with a little speed, got to the middle of the hill and the car died. Tried to turn it back over, but it wasn't catching. Was stopping traffic so I had to roll backwards on to the shoulder.

I could tell that it was trying to fire when I was engaging the ignition but as soon as I let off the ignition it would die. Looked under the hood, thought that maybe it was due to heat (it wasn't). Called the flat bed, two hour wait, in 85 degree heat blazing sun. I waited 5 min and decided to try to turn it over again, nothing.

The fact it wanted to start when I had the ignition engaged made me try something. This time I engaged the ignition then instead of letting go of the key I kept enough pressure on the key to be right at the point where the next bit of pressure would engage the starter.

The engine stayed running, and running good. As soon as I released the pressure from the key it would die. Luckily my wife was in the car. I started it again, kept the key pressure with my right, steered with my left and had my wife throw the gears. (1st to 3rd works surprisingly well)

About 5 min into this, and going downhill, I decided to take the pressure off the key to see what would happen. Nothing, ran fine the 10 minutes back home.

Anyone have any idea what is going on?

 

[bm02tj]

bad ing switch ,bad connections or bad ballast resistor you need to follow to find problem

 

[wsutard]

Good info because I have no idea what the ballast resistor is. Any info you can provide specific to b bodies?

 

[wsutard]

bad ing switch ,bad connections or bad ballast resistor you need to follow to find problem

huh, google seems to know a lot of stuff. Its that white thing on the firewall with the 4 plugs going into it.

Is there a way to modernize that ballast?

 

[Mopars & Missiles]

This is NOT a ballast issue, you have a bad ignition switch. Replace it or repair it and you'll be fine.


OK, I'll modify this since you added the "butt connector" issue that I didn't know about previously. It may not be the switch, the wiring is now HIGHLY suspect. Still don't think it is the ballast resistor though.

 

[Ranger16]

The ballast resistor is bypassed during cranking, putting a full 12v to the coil via the IGN2 contact on the key switch. Once started, the bypass is eliminated and current flows through ING1 and THROUGH the ballast resistor. If it runs when you hold the key and dies when the key is released, I'd put money on the ballast resistor. Although a bad key switch can't be ruled out. The resistor should be easy to test for continuity.

You don't mention year or model, but it should look like this.

or this (4 plug type)

and be mounted on the firewall.

You can see mine mounted above the ECU.

 

[wsutard]

I have the 4 prong type. 69 Coronet. Looking closer at it the previous owner loved him some butt connectors. Almost every wire is connected via a butt connector.

Would MDS replace the resistor and thus modernize this system?

 

[Ranger16]

Not real familiar with how the MSD system works, but I think so. Someone else can verify that. That said, replacing the resistor (and keeping a spare in the glove box) is MUCH cheaper and easier.

 

[wsutard]

OK, more detail. I took it out last night to test it again. Fired right up, idled well, once warm I took it to the local store. No issues. It sat for about 10 min, started it up, while it did start it was idling all over the place, revving up and down from 200 to 600. I decided to see what would happen if I ran it like this, didn't make it out of the parking lot before it died. Tried to start it up, same issue.

Here is the new part, when I finally got it started again using my key trick all the electrical in the cab was not working. No lights, no blinkers, no tachometer. Nothing but the engine. All the electrical came back on once I was about 5 minutes into the trip home.

I think this electrical issue points to a problem with the key system. However, I am going to test the ballast resistor first since it is so easy to get at. Can anyone guide me through testing these two components?

 

[Lionized]

Do you have the rallye instruments in this car? If so, disconnect the battery and get under there to ensure the terminals are tight.

 

[wsutard]

Do you have the rallye instruments in this car? If so, disconnect the battery and get under there to ensure the terminals are tight.

Nope, just the standard cluster with the sweep speedo.

 

[Lionized]

Nope, just the standard cluster with the sweep speedo.

Check the starter relay and, more specifically, the ignition wire from the bulkhead connector to the relay (condition and contact). If both of those are in acceptable working condition it's the ignition switch.

 

[wsutard]

Check the starter relay and, more specifically, the ignition wire from the bulkhead connector to the relay (condition and contact). If both of those are in acceptable working condition it's the ignition switch.

Would you mind guiding me to where these are? I'm new the the electrical ok this car

 

[Lionized]

Would you mind guiding me to where these are? I'm new the the electrical ok this car

Ignore the terminal I'm holding in the foreground. What you will look for is the yellow with black tracer going from the bulkhead foreword light harness to the starter relay on the firewall.
If you're new to this I highly recommend purchasing a copy of the Factory Service Manual. You should also download a copy so you have it on your phone.

http://www.mymopar.com/index.php?pid=109

 

[Mopars & Missiles]

Ignore the terminal I'm holding in the foreground. What you will look for is the yellow with black tracer going from the bulkhead foreword light harness to the starter relay on the firewall.
If you're new to this I highly recommend purchasing a copy of the Factory Service Manual. You should also download a copy so you have it on your phone.

http://www.mymopar.com/index.php?pid=109

View attachment 357679

All you are describing is the "START" circuit, not the "IGNITION" circuit.

Yes, you need the FSM like mentioned by Lionized.

 

[wsutard]

I have the FSM. Was hard to pin point the section I needed to read.

Anyway, I touched the yellow wire and this happened.

 

[Mopars & Missiles]

I have the FSM. Was hard to pin point the section I needed to read.

Anyway, I touched the yellow wire and this happened.
View attachment 357721

Well that will sure keep it from cranking over! Yellow is 12v start command from ignition switch. Brown is relay coil GROUND from NSS on transmission. Both signals MUST be present at the starter relay for the starter to be engaged to crank the engine over.

 

[wsutard]

Huh. Well it has always been cranking over. Lucky I touched this I guess cause it was going to come off, soon.

 

[Mopars & Missiles]

Whoever did all that "butt splicing" ought to be kicked in their "splice".

 

[wsutard]

Agreed.