Engine just quits after it's warm and running . Need input

71D100 · Post by **71D100** » Sun Aug 21, 2005 6:26 pm

I've got a wierd problem with my 71D. After it's started and running for a bit, usually when it gets to operating temp, the damn thing just quits. Sometimes it does it when I'm on the driveway idling, and others when I've driven it a few miles. Just started doing this. When it stops and I try to restart, it acts like no fuel/spark. Installed are a new MP perf elec ignition, ballast, coil, ground, starter relay, ignition switch. Even the starter and cables are new. If I can manage to get it restarted, it bucks, coughs and sputters. I'm suspecting the orange box is bad.

Any suggestions? Anyone had this same issue?

Thanks

Website · Post by **wideblock** » Sun Aug 21, 2005 6:45 pm

i had the same problem with my 69 charger. turned out to be the ignition box. it would work fine till it got a bit hot. turns out it had a busted connection that would make contact untill everything got hot and expanded a bit, then it would go to hell. lett the car cool, and she would fire right back up and go another 3 or 4 miles before dyeing again. what really sucked, the first time it did this was on a date where i drove the charger to impress the new woman

71D100 · Post by **71D100** » Sun Aug 21, 2005 6:51 pm

Did Chrysler have a bad run on these? This box is new. I may just go to a chrome box and be done with it. Would it be beneficial to switch out the external regulator and go with an internally regulated alternator? Maybe this caused the box to go bad?

Thanks for the reply and confirming what I thought it might be.

Jon

Website · Post by **wideblock** » Sun Aug 21, 2005 6:55 pm

i went thru 3 before i realized it was a location problem. my box was getting too hot, and they kept frying after a week or so. id stay away from chrome, they look pretty, but dont displace heat as well as the painted ones. if its a show truck, you wont have any problems, but a driver is better served with the painted ones. im also told bad grounds will shorten thier life, so id check and be sure all your grounds are clean and tight. i havent ever heard of the alt being the cause of failure.

71D100 · Post by **71D100** » Sun Aug 21, 2005 7:07 pm

I'll go through the truck next weekend and check all the grounds. I was thinking of installing an extra ground from block to frame and then a new one from the body to block. That should fix any ground issues. Then I'm going to move the box from the firewall to the fenderwell. It gets damn hot under the hood in the Nevada desert during summer.

Thanks Trey

Jeffc · Post by **Jeffc** » Sun Aug 21, 2005 7:27 pm

Most likely a grounding issue with the box, run a ground wire from one mount hole on the box to engine block or neg battery cable, bet it fixes it.......

Had the same problem once, had a devil of a time tying to find the problem till I saw a spark between the fender and fire wall, then it all made sence, it couldn't find a ground...... ALWAYS run a ground wire now between the mount hole and a good grounding point,

Post by **oneowner71** » Mon Aug 22, 2005 11:14 am

from what I understand, there was a bad run on the orange boxes a while back, but no one wants to tell me how far back that was. I've had mine on the firewall for years with no problems, just centered over the back of the motor by the factory one. Good luck, and keep us posted.

71D100 · Post by **71D100** » Fri Aug 26, 2005 12:42 am

Ok, checked and rechecked all electrical connections and even went as far as running new cabling and a special ground for the control box, still stalls after it gets warm. I installed a ground cable from the body to the bellhousing and from the engine to the frame. I know that a bad ground can't be the problem. Fuel delivery looks good (carb and fuel pump are also new). The distributor was checked with a brass gauge and all points are in spec.

I'm wondering at this point if I have a lot of trash in the bottom of the gas tank that might be causing all this. Could that be the problem? All lines are new and the fuel seems to flow as it should. Is it possible that some junk in the tank is moving toward the sump as it warms up?

I can't get this one figured out and I'm starting to pull on the few hairs that are left on my head...

Thomas · Post by **Thomas** » Fri Aug 26, 2005 9:56 am

I'm certainly not the most savvy guy on here, but what kind of choke do you have? The mechanical one I had on the original intake gave me a ton of trouble so I switched to a manual choke. Later I had added an aluminum intake w/4 bbl that had an electric choke. Both of the latter work FAR better than the old sticky mechanical one. You say it's a new carb, is it on the original intake? Maybe just take off the air filter and see if it has opened up when it's warm. Worth a shot if you haven't already done so....

Jeffc · Post by **Jeffc** » Fri Aug 26, 2005 11:16 am

Do you get any sucking sound from the tank if you take the cap off? how about just after it dies?
Yes, could also be stuff in the fuel line.
Go grab one of those cheap clear plastic fuel filters,
will tell if your getting fuel in the line or not at anygiven time, you'll also see and gunk that might be in the line.

I've had that problem before, both line blockage and/or no venting of tank cause that kind of problem.
Runs great till it uses up fuel in the line or has too much vacumm in the tank......

71D100 · Post by **71D100** » Fri Aug 26, 2005 9:24 pm

No vacuum type noises from the tank Jeff. I'm going to yank the tank anyway and have it boiled out. Hasn't been done since it was new, so, I figure it can't hurt any. Your input is appreciated and I do believe this is the problem. It makes sense that it stalls due to fuel starvation. It ran real hot the other day and now that I think about it, it was probably running real lean due to lack of fuel. And me doing 75 down the freeway, I really didn't notice the lean condition.

Website · Post by **wideblock** » Sat Aug 27, 2005 3:39 pm

if its running hot, your stalling could be from a vapor lock. i agree with jeff, put on a clear filter in line, when it stalls, get out and see if the filter is empty. if its not, then fuel starvation isnt the problem. if it is, then try running a while with no gas cap. if it runs fine, then you need a new vented tank, if it stalls again, then id go for the tank cleaning.

71D100 · Post by **71D100** » Thu Sep 01, 2005 8:10 pm

OK, time for my saga, volume II:

The tank was ok. Flows fuel very well (especially when you pull the feed line under the truck without a rag and/or gas can handy). Put a clear filter in the line to monitor fuel delivery, it's ok. Truck stalled and fuel filter was full. Also, re-pulled that fuel line when it happened and got drenched. There are no vacuum leaks anywhere that I can find.

Ok, I didn't have this problem before I installed the Mopar electronic conversion. So, in my infinite wisdom (all 43 yrs of it), I rechecked all the wired connections to make sure they were all nice and tight and my alzheimers wasn't settling in. They are.

There are things in this universe that make a person go "hmmm". Then there are the old Dodge trucks. They, unfortunately, make a person go "$%*^&$" sometimes. Time to break out the multimeter and start checking every single stinking connection in the engine electrical system and locate where the short might be. I am convinced there is a short of some sort in the system that is causing this to happen.

Questions: Can the starter relay, solenoid and or ignition switch cause this to happen? They are all new, but, I know that doesn't mean they aren't bad.

What are the differences between the point voltage reg and the Electronic voltage reg?

First stop, the ignition switch.... Of course, if there other suggestions, I am definitely up for listening to them...

Wish me luck and if I come up missing, I'd look at the Dodge.. Cover me, I'm going in..

duracell · Post by **duracell** » Fri Sep 02, 2005 10:29 am

i'd replace the mp orange box with a new one before you tear the truck appart

71D100 · Post by **71D100** » Fri Sep 02, 2005 1:42 pm

Already changed it out. I used a stock box and it does the same thing. I can't for the life of me figure out what went haywire. Ran great, then just started doing this.

Thanks for the suggest. Steve

Thomas · Post by **Thomas** » Tue Sep 06, 2005 10:02 pm

71D100 wrote:OK, time for my saga, volume II:

What are the differences between the point voltage reg and the Electronic voltage reg?

First stop, the ignition switch.... Of course, if there other suggestions, I am definitely up for listening to them...

Wish me luck and if I come up missing, I'd look at the Dodge.. Cover me, I'm going in..

Do you have an electronic voltage regulator?? As I understand, you do need one. If you are running an electronic ignition with a points reg. that might be the problem itself. An elec. ignition needs more juice than what a points reg will give.

taintedspeed · Post by **taintedspeed** » Tue Sep 13, 2005 9:32 pm

just in case you havent done this as all i did was skim the responses. this has happened to me twice. the magnetic pickup inside the distributor can and does go bad. it is like a $20 part and it is not that bad to change. like i said it has happened to me twice. and one of the times, jeffc helped me diagnose it. i hope i helped. -TS -Randy

Hoss · Post by **Hoss** » Wed Sep 14, 2005 2:14 pm

Sounds like the coil. The coil will give you the same problems as a control box and alot of people over look them. You should do an ohms check on the coil both cold and after the engine dies.
A good shop manual will give you the proceedure and the correct resistance for the coil both positive and negative sides.
Ken

71D100 · Post by **71D100** » Wed Sep 14, 2005 9:26 pm

Well, I'm going to pull the distributor and make sure there are no places it could possibly short. Also, will be checking the coil. Thanks again for all the input, it looks like I'm just going to have to take my time (good thing it's not my daily driver yet) and double check everything. I can't wait to be able to drive this truck on a regular basis, it gets a ton of looks on the road from just about everyone. Been a long time since it's been road worthy.

I'll keep everyone in the loop and let you know when I find the problem and how I resolved it. My problem today will contain someones solution tomorrow.

Great site, you guys are great.

Jeffc · Post by **Jeffc** » Thu Sep 15, 2005 12:03 pm

taintedspeed wrote:just in case you havent done this as all i did was skim the responses. this has happened to me twice. the magnetic pickup inside the distributor can and does go bad. it is like a $20 part and it is not that bad to change. like i said it has happened to me twice. and one of the times, jeffc helped me diagnose it. i hope i helped. -TS -Randy

HA! I remmeber that well, acted like a heat sink, worked fine when cold, run fine till you shut it off, then would not fire for love or money..........would start again once it cooled off.
Did it act the same way on the 2nd one you lost Randy?