Dying & Starting Issues.

[Bruce chl70]

Situation: This is a 1970 Challenger with a 318 engine - stock except for a Chrysler electronic ignition upgrade done about 20 yrs. ago. The problem first happened when trying to leave work one night - the car cranked but would not start; tried for about 5 minutes off & on. Then after waitng about 20 minutes, it started right up! It did this several times. The next thing it does now is dies when rolling but slowing down like at a traffic light. And then I'm stuck at the light for 5 minutes blocking traffic until it finally starts again! It has also died when slowly driving for about 2 seconds and then started back up without me doing anything!
I'm getting scared to drive it.
Does anyone have an idea on this? I was thinking there might be a problem with the ignition switch or flooding in the carb?
Please help!

Thanks,
Bruce

 

[moparleo]

I would check all of the ignition systems connections, like the wires to coil, wiring to balast resistor, wiring to ecm, wiring to starter and relay etc... Unplug and clean all wiring connections and grounds.

 

[Bruce chl70]

Thanks, Leo,
I did a quick visual check but I probably didn't touch everything to make sure they were tight. I will double check the connections tomorrow; got to work tonight.
Thanks again,
Bruce

 

[DetMatt1]

It has also died when slowly driving for about 2 seconds and then started back up without me doing anything!
I'm getting scared to drive it.
Does anyone have an idea on this? I was thinking there might be a problem with the ignition switch or flooding in the carb?
Please help!

Thanks,
Bruce[/QUOTE]

Hey Bruce, do you mean to say that the engine has actually stalled and restarted on its own without you hitting the key?

 

[burdar]

When it dies, does it just suddenly shut off or doesn it sputter and die? If it instantly dies(like you turned off the key) then I would suspect an electrical problem. If it sputters and dies, then I would suspect a fuel issue.

If it just dies all of a sudden, look over ALL the wiring very closely. Make sure to check the bulkhead connector at the firewall. This is a soarce of many problems. Make sure all the contacts are clean and dry. Use some diealectric grease on all the contacts. Make sure the connection is tight...not loose.

What ECU are you running? The orange MP box? If so, I'd try another known good box. The orange boxes have gotten a very bad reputaion lately for failing. Check for spark when you are having the problem.

If the car sputters and dies, take the air cleaner off and make sure you are getting fuel at the carb.

 

[Bruce chl70]

Hello DetMatt1 and Burdar,
Yes, one time it shut off and about 2 seconds later caught again and was running without me touching the key!
And it doesn't sputter or make any noise, it just cuts off and I'm coasting!
I am running the orange MP box, but I don't have any others except an old standard unit that I'm not sure about. I will check for spark if it does it at my garage, but it usually only does it on a busy highway!
Thanks for the ideas and I hope to check it out some tonight.

Bruce

 

[Bruce chl70]

Well, last night I checked all electrical connections and all are tight. I also swapped in a diffedrent MP Orange ecm and made it to work without stalling. So maybe driving it throughout today will determine if it was the ecm?
Thanks for the suggestions!
Bruce

 

[Chryco Psycho]

check the gap between the reluctor & pick up , could be a bad ballast also they are cheap so replacing it would be a good call too

 

[Bruce chl70]

Thanks for the input Chryco Psycho, I might get a spare ballast resistor to have on hand and ohm-out the current one - it seems good.

Burdar seems to have nailed the diagnosis - BAD MP Orange Box! It was only 2 yrs. old and had no seepage of the insulating goo! I put that one on because the previous one started leaking the "goo." So yesterday I put the old one back on and the car starts like a champ and there has been no sign of stalling! But since that one is an old unit, I'm going to buy a "cheapie" ECU from NAPA.
Thanks for all the answers and help; it really is amazing what troubles and different symptoms that ECU box can cause! Now I'm not afraid to drive the car.

Thanks again you guys got me on the right track,
Bruce

 

[Bruce chl70]

Thanks for the input Chryco Psycho, I will get another ballast resistor for a spare and ohm-out the existing one, it seems O.K.
Burdar seems to have nailed the diagnosis - BAD MP ECU Box! After putting an old ECU on yesterday, the car starts like a champ and shows no signs of stalling! The unit that I took off was only 2 yrs. old and showed no signs of leakage of the insulating "goo." That was the reason I did the change-out 2 yrs. ago, the old one was seeping "goo." So now I'm going to buy a cheapie ECU box from NAPA.

Thanks again for the help - you guys got me on the right track.
Bruce

 

[burdar]

I've heard of the MP boxes lasting for 1 hour and then not working again. Definately a problem with those. When my car is on the road, I'll be keeping a spare ECU and ballast in the car.

Checking the reluctor gap is a good idea too. I tired to save a few bucks once and bought the Summit brand electronic ignition kit instead of the MP kit. I had an intermitent no start problem and traced it back to a damaged pick-up in the distributor. I sent the kit back and bought the MP kit.

 

[Chryco Psycho]

Natcho on the Charger site has had some success changing the transistor on the ECU & repairing them with a better Motorola transistor
http://www.dodgecharger.com/forum/index.php/topic,92253.0.html