car suddenly quits...fuel or ign?

[DeeTee]

this has ocurred several times in the last few months: I have an original 68 superbee 383 auto coupe that I drive on occasion (to happy hours) here in the desert (Palm Springs area). I purchased this car new and it has an intact engine,trans & diff.(206K miles). Approx 15 years ago, I had a mech friend install an electronic ign system (Mopar orange/blue box on the firewall ,Mallory electronic coil(with ballast) & pointless distributer. The orig ceramic ballast on the firewall is still wired into the system. Over the past 5 years, I have driven the car 2 or 3 times a week for approx 10 miles max (round trip). During the last few trips, the car suddenly quits running while cruising (40 mph) after 2 or 3 miles. After I pull to the side of the road and try to re-start, it tries to catch, but won't start.Then subsequent cranking gets no reaction. After waiting 10 or 15 minutes, it will start immediately and run perfect. After libations and fun (1 or 2 hours), restarting requires cranking for 5 to 10 seconds before engaging (this always occurs). Then after about two or 3 miles on the return home, the car just quits running while driving normal speed. The last time this happened, I was fortunate to have a couple of guys stop, and push me to the curb. Again, while initial cranking produced a few sputters...subsequent cranking was fruitless.I had one of the guys pull the coil wire from the distributer, and he said that there was no spark. I left the car sit over night, and the next morning it started up immediately and it ran perfectly. On both occasions, I thought that I smelled hot wires while driving. This morning, the car started immediately and ran fine for 30 minutes (idling).
Anyone?

 

[Belle66]

Been in similar situations before...I'd go buy a new coil and see what happens. If you don't scratch the paint on the coil, you can return it.

 

[1967coronet440]

I'm no mechanic but Sounds like fuel issue, very well could be either though

 

[Belle66]

I'm no mechanic but Sounds like fuel issue, very well could be either though

Yup...it's usually one or the other.

 

[1967coronet440]

My coronet used to do the same thing, fuel was boiling once I turned it off and it would take a while to re start.

 

[Mike67]

One thing you failed to describe is how its dying. Is it a spit and sputter or is it more of an immidiate shut down of ignition?
Im leaning towards something electrical, coil, resistor, power feed to the resistor ect.
Not saying that it cant be something fuel related like clogged filter, pickup weak pump ect. Youve never had a history of vapor lock, is it running hotter than normal?
My suspicion is either coil or ballast...cheapest things to check too! When they are getting hot the circuit is opening.

 

[Dennis H]

Ethanol boils at 173 or so. Need to know how it quits as above. Fuel usually warns. Instant like you threw the keys out the window could be bukhead connector.

 

[DeeTee]

One thing you failed to describe is how its dying. Is it a spit and sputter or is it more of an immidiate shut down of ignition?
Im leaning towards something electrical, coil, resistor, power feed to the resistor ect.
Not saying that it cant be something fuel related like clogged filter, pickup weak pump ect. Youve never had a history of vapor lock, is it running hotter than normal?
My suspicion is either coil or ballast...cheapest things to check too! When they are getting hot the circuit is opening.

 

[DeeTee]

immediate shutdown...no sputtering. recently changed the fuel filter (nothing inside the old one). the ceramic balast (on the firewall) appears ok...(no cracks)

 

[idrivemopar]

Sounds electrical, I would check grounds on ECU and connections on coil and ballast.

 

[DeeTee]

All the connections are tight. I did measure the current across the coil leads while it was running...started out at 3.5 v and gradually climbed to 4v. Isn't that low??...I thought it was supposed to be in the 8 to 10 range.

 

[DeeTee]

My coronet used to do the same thing, fuel was boiling once I turned it off and it would take a while to re start.

I have a feeling that you may be right...at least on part of my problem (the hot re-starts)...after it sits for a day or two, it starts in the first 1/2 second. Not sure how to prevent that.
I think that I'm going to try changing the coil(for the instantaneous shutdown problem).

 

[RT K_line]

Iv'e seen a coil and ecu (orange box) do the same thing, just shut off like you turned the key off. I always carried a spare ecu in the car. If its the coil sometimes cooling it down with water may help it restart sooner.

 

[DeeTee]

Thank you. ...will do that. Is 4 volts across the coil terminals normal??

 

[RT K_line]

I'm not sure about the voltage reading, I have switched to the MSD system. I still have my spare ecu if you need one though.

 

[Mike67]

Do you have 12v on the switch side? If not make sure you are testing to a good ground. If you get 12v you make need to install a star washer or clean the mounting surface/ yoke on the ballast & ecu.
If youre not getting 12v it might be your bulkhead like idrive stated or a possible fusible link if it has one.
I would start with the ballast resistor, $10 +/-.

 

[PurpleBeeper]

You know, I had a '73 Charger that would do exactly what you describe....drives fine then just shuts off. I was burning up ignition boxes. Sometimes the back of them "looks melted or oily" when they go bad.

I suggest you carry one extra spark plug, a 1/2 cup of gasoline with you and a buddy with you. Drive it around the block until it does it again. While it's not starting, pull one spark plug wire, put your plug in it, ground that plug to the block/bolt & have your buddy crank the engine to see if you have spark (don't lean on the car while doing this). If you DO have spark, pour a couple tablespoons of gas down the throat of the carburetor and crank it again. If it starts then you're probably boiling fuel (vapor lock). You can also check this by pulling the throttle by hand (engine off), looking down the throat of the carburetor and see if you're getting a squirt.

I "think" the voltage after the ballast resistor should be 7 volts.

 

[the mississippi madman]

My power wagon was doing something similar after running for a little while it would just start getting weaker and weaker until it died and I'd have to sit there for a minute before we could recrank it and drive on. we ended up taking off the external ballast resistor and adding a coil with an internal ballast resistor and that seem to fix the problem

 

[oldbee]

If you have orig ignition the ballast being bad will stop it from running when is 'on' no matter when. You shouldn't even be able to get out garage. Bulkhead,coil, maybe fuel(but doesn't quite sound like it)

 

[NJRR]

I had a similar problem in my 70 RR. Was the orange box. When it got hot, stopped working. I replaced it and no more issue. I carry a spare now. They have a cheap one on ebay that is good for an emergency spare. Comes from Mancini Racing.

http://www.ebay.com/itm/232005380209?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT