Electrical issue (?) with my Dart

[terrible one]

Okay I know it's a Dart but still . . .

I have a problem in my electrical system I guess. Starting with yesterday, the car stalled in the middle of driving and would not start for about five minutes. It turns over just fine but won't fire. After those few minutes it started and drove fine. Then today, it did it again. This time it took about ten minutes before it would go ahead and turn over. Once I finally got it started after this time, heading home, it died again. After this, I got it to crank up and run for about 10 seconds then it was dead again. After I got it towed back to its home I went back to try it again hours later and it still wouldn't start.

I pulled the ignition module and had it tested and it checked out fine. Next I bought a ballast resistor to try tomorrow, but from what the guy at the store was telling me the symptom of the ballast going bad is that the car will crank and run but will die as soon as you let the ignition switch recoil, so that doesn't seem to be a likely cause.

Anyone got any ideas? 

[69bronzeT5]

I'm in the same boat as you with my Duster. Unknown electrical gremlins.

[Nacho-RT74]

I was on EXACTLY same deal untill yesterday, getting usually perfect starting up but then not anymore quite often ( once in fact engine simply died when running)... MOSTLY SURE bad ground at ECU. That would it be my first though. Then be sure plug at dist is clean and good plugged.

One way to test fro a good ground is check continuity between negative bat post, and pin 4 at ECU ( what is one of the dist wires )

You can in fact check for that ground continuity directly at dist pick up coil plug, coming from engine harness. Any reading NOT CLOSE to 0 ohms is a bad ground at ECU module ( or with batt-body itself )

On one of my testing readings I HAD 84 OHMs 

I had striped ECU bolt holes on firewall. At the end I fit C speed nuts fasteners making a slot on body to fit the fastener and keep original look from exterior. The slot and fastener is hidden by the Module itself so is not noticeable. Mounting the fastener also stripped the firewall so there I'm getting the good ground. ( 0.7 omhs, just by erratic tester measurement  ). I diodn't want a Jumper wire hanging around to get the good ground at Module

Originally the ground was taken by the same bolt thread and firewall hole, what wasn't working good anymore on the striped hole.

[skip68]

The coil can do that too.       Check the coil. 

[Nacho-RT74]

yeah, that too

[terrible one]

THANK YOU guys for the leads! You guys might be onto something because today I put the ECU back after it tested positive and added the new ballast to the equation and it fired right up and ran for about a minute before I turned it off. I then put the old ballast to see if it was the new ballast that did the trick, but it started with that one too. However, it quickly died and I couldn't get it to start again, so it's gotta be something else.

I hope it really is a grounding issue, it would be nice to have a simple/free fix for once. I'll get after it tomorrow hopefully. 

[Todd Wilson]

I have had this issue happen several times over the years.  Theres been 3 different problems that can cause this.

ECU going bad.

Replace it.

ECU loosing a ground.......

Due to rust or corrosion. Due to fresh paint and not using star washings to get a good ground. I have ran a ground wire on my old 74 truck from my ECU. If it loses ground it will die and or not start.

Bad ballast resistor or connection problems.

This can be an odd one. A bad ballast resistor will allow the vehicle to start and then die if you let off the key. This is true. And is the most common thing to happen when the ballast goes out.
Some will argue with the next finding I have  but I have seen a bad engine miss due to a ballast resistor.  Just this week my 74 truck was shutting itself off at random times and or not starting. I replaced the ballast and noticed one of the connections had shown some signs of heat.  This tells me that the connection was poor to the ballast.

What I have found on these old Mopars is all the connectors are showing thier age and getting oxidized.  They dont allow the current to flow properly. Resistance creates heat and then eventually problems. What I had done is I use a product called DeOxit. This is a high dollar tuner wash that has a chemical to deox the metal surface. Get the oxide corrosion off.  Since doing this my problem has gone away and the truck has actually perked up a lot in the electrical department.

One other problem could be a exposed wire in the engine harness on the ignition side grounding out at certain times giving you fits. All those wires on the engine harness are old and probably brittle. Could be a little crack or wear thru spot in the insulation and tape.

These would probably be the usual things to happen it could be some other things.


Todd

[Corellian Corvette]

What type of coil are you using? If you have an aftermarket coil and you're mounting it horizontally, they can go bad.

This is not often something that is well known, but aftermarket oil-filled coils need to be mounted vertically to keep the internal windings lubricated. MSD makes a special "race" coil that can be mounted horizontally, which is what I use on all my cars after my aftermarket coils kept going bad.

After the coils cool, they will work again but only for a short time.

I agree however that Todd's analysis is right on. I used to have a Mustang that would die out on my occasionally for no reason. After sitting, it would run again. Turns out the ignition module was original, and it would heat up and stop working. Took me forever to figure it out.

Either your coil is bad, your ballast is bad (no voltage or too much voltage to the coil), or your ignition module is going.

[defiance]

I had nearly the exact same symptoms when my coil was toast.  It would die when it heated up enough.  When it had a few minutes to cool down the thing would run fine again.  Replaced the coil and it all worked beautifully.

[Todd Wilson]

I agree however that Todd's analysis is right on. I used to have a Mustang that would die out on my occasionally for no reason. After sitting, it would run again. Turns out the ignition module was original, and it would heat up and stop working. Took me forever to figure it out.

Yup! Stuff can test good until it gets warmed up and or rattled around a little bit and then the problems happen.

Todd

[terrible one]

Wow! I'm glad to see that this thread was brought back up!

I really appreciate the information everyone. As I said earlier, I replaced the ballast already and while that wasn't the problem it is eliminated. The coil is not aftermarket and looks original to me. The car has 79k original miles so I wouldn't doubt that too much. I also thought that maybe the ECU was just testing good and really was bad.

Right now, my plan of attack is to take the ECU back off and get a wire brush to it and the mounting point on the fender as well as the bolts, check through the engine compartment harness, etc. and see if that works. If not, I'll buy another ECU and see if it solves the problem (if not, I can always return it) I suppose if it's not the ECU or the ECU ground then I'll look at the coil/ smaller things like cracks, other bad grounds, etc.

[Todd Wilson]

Wow! I'm glad to see that this thread was brought back up!

I really appreciate the information everyone. As I said earlier, I replaced the ballast already and while that wasn't the problem it is eliminated. The coil is not aftermarket and looks original to me. The car has 79k original miles so I wouldn't doubt that too much. I also thought that maybe the ECU was just testing good and really was bad.

Right now, my plan of attack is to take the ECU back off and get a wire brush to it and the mounting point on the fender as well as the bolts, check through the engine compartment harness, etc. and see if that works. If not, I'll buy another ECU and see if it solves the problem (if not, I can always return it) I suppose if it's not the ECU or the ECU ground then I'll look at the coil/ smaller things like cracks, other bad grounds, etc.

ECU's are expensive. Most places will not take returns on electric parts. You may be stuck with the ECU.

Todd

[terrible one]

Hmm you bring up a good and familiar point about no returns on electrical components. . .


I have the orange ECU (new) that came in the electric ignition kit that I'm going to use on the Charger. Interchangable?

P.S. here's the ECU I've got on the shelf: http://store.summitracing.com/partdetail.asp?autofilter=1&part=DCC-4007968&N=700+115&autoview=sku

[Todd Wilson]

Hmm you bring up a good and familiar point about no returns on electrical components. . .


I have the orange ECU (new) that came in the electric ignition kit that I'm going to use on the Charger. Interchangable?

P.S. here's the ECU I've got on the shelf: http://store.summitracing.com/partdetail.asp?autofilter=1&part=DCC-4007968&N=700+115&autoview=sku

They are interchangable. Swap it out and see if that cures your problem.

Todd

[Ghoste]

FWIW, Mancini's sells cheap ecu's that are handy to have as a spare or test unit.  They're about 20 bucks if memory serves.

[terrible one]

Cool deal, I'll definitely swap the ECU out first once I get home next week. thanks guys!