Suddenly shuts off..SOLVED

[mannye]

My 383 auto ragtop that I recently changed over to electronic ignition (Petronix or however that is spelled) was working great after the conversion for a few months. I drove it more than ever and I loved the cooler and quieter running I was getting. Then about a month later it just shuts off as I am driving down the road!

It would start, run for a few seconds, then die. then it would run for a while agan and then strt doing it again. I figure the original 40 year old fuel pump finally took a dump, so i change it out. Runs great, fuel pump was tired for sure. I figure I have it licked. Then it did it again.

This time i notice the "charge" guage is pinned all the way to "C". Does this mean my regulator is dead? The battery is getting about 14 volts at idle according to my multimeter.

 

[george68hemirr]

Re: Suddenly shuts off..

My 383 auto ragtop that I recently changed over to electronic ignition (Petronix or however that is spelled) was working great after the conversion for a few months. I drove it more than ever and I loved the cooler and quieter running I was getting. Then about a month later it just shuts off as I am driving down the road!

It would start, run for a few seconds, then die. then it would run for a while agan and then strt doing it again. I figure the original 40 year old fuel pump finally took a dump, so i change it out. Runs great, fuel pump was tired for sure. I figure I have it licked. Then it did it again.

This time i notice the "charge" guage is pinned all the way to "C". Does this mean my regulator is dead? The battery is getting about 14 volts at idle according to my multimeter.

it sounds like its over charging since the gauge is pinned.....i would change that 40 year old regulator and see if that changes the gauge.....you should have 13.5 to 14 volts at the battery
when you changed the fuel punp did you notice if the fuel line was close to you exhaust manifold......it almost sounds like vapor lock or your gas got jelled from sitting too long....do you use stabil fuel conditioner when you store the car for a period of time??
also look inside your distributor.....when you changed over to that Petronix look closely at the wires....one wire could be pinched or chaffed and look where it goes through the distributor housing....you should have a rubber grommet there where the wires pass through......i fixed a buddies cobra with that same problem.......good luck and let us know how you make out

 

[mannye]

Re: Suddenly shuts off..

Thanks I'll take a look at that fuel line. I really don't want to resort to taking it to the mechanic. The rainy season is starting and I like to stay close to home during the summer. Those quarter panels can hold a LOT of water in a tropical rainstorm. I remember wondering why the quarters had drain plugs when I got my first ragtop about 20 years ago, and then discovering the answer the hard way!

I think your vapor lock issue may have some legs. I notice it's struggling to turn over sometimes when I am restarting it. I also need to get around to blocking off that intake manifold thing. I don't need any help heating up the intake charge in the tropics.

 

[Basketcase]

Re: Suddenly shuts off..

a couple weeks after I got my car, it started douing the same thing. the ECU box was bad. it'll do that too if it isn't grounded good.

 

[dobie]

Re: Suddenly shuts off..

If all else fails with it shutting off for no reason, look at the pickup coil in the distributor. I converted mine over with all new stuff from M.P. After a month or so, it'd just die for no apparent reason. It took some frustrations, but I finally fixed it. I ended up buying a new pickup coil and have been fine ever since.

 

[Basketcase]

Re: Suddenly shuts off..

'nuther reason we took the new fangled stuff off mine. In 30 years, I've ever only had one set of points give me problems, but that was because they were shot, and the car was in the middle of getting painted and I simply forgot to put new ones in.

 

[mcmopar]

Re: Suddenly shuts off..

I used to have to tune up my 1st road runner (the one I got from my dad - Q5, 4 speed, black bucket seat interior) every month because the points were pitted so badly and #8 spark plug was oil fouled. After a tune up it ran like a raped ape!

 

[george68hemirr]

Re: Suddenly shuts off..

Thanks I'll take a look at that fuel line. I really don't want to resort to taking it to the mechanic. The rainy season is starting and I like to stay close to home during the summer. Those quarter panels can hold a LOT of water in a tropical rainstorm. I remember wondering why the quarters had drain plugs when I got my first ragtop about 20 years ago, and then discovering the answer the hard way!

I think your vapor lock issue may have some legs. I notice it's struggling to turn over sometimes when I am restarting it. I also need to get around to blocking off that intake manifold thing. I don't need any help heating up the intake charge in the tropics.

well how did you make out.....let us know

 

[mannye]

Re: Suddenly shuts off..

OK... here's what I got so far... I checked the filter... not obstructed, sending unit is not reading full, so new one is on the way, but there is plenty of fuel making it to the pump, which is new.

I drove around today and all was well. I see the charge needle pinned, turn on the headlights, and it goes back down to the middle, headlights off, back to pinned full charge. But I am running fine. I have a feeling the shutting down might not have anything to do with the electrical system, although it's clear there's something going on there that needs fixing.

Then it shuts down. I pop it into neutral while still folling and it starts right back up no problem. I drive on to see if it happens again, and sure enough, while waiting for a light to change, off. This time when I put it in neutral it is struggling to turn over... hit the ignition and it goes "RRRRR" like one quarter turn. It really feels like vapor lock. after a few slow quarter turns, the battery gives up.

I push it over to the side, wait a minute, try again... it fires up and dies right away. Try again... fires up and dies again. Then back to the slow quarter turn "RRRR" and the click of battery begging for mercy.

So I pop open an ice cold Coke from my trusty mini igloo and wait about 10 minutes... try it, starts right up and I drive home without any more incident (about 5 minutes from where I was).

I checked the fuel line, and nothing is close to a manifold. The only thing I see is that the fuel filter, being right up on the intake manifold, might be getting too hot?

 

[george68hemirr]

Re: Suddenly shuts off..UPDATE

try relocating it and see what happens

 

[69hemibeep]

Re: Suddenly shuts off..UPDATE

Sound like a marginal starter, gets hot and weak. Vapor lock is a fuel boiling problem, might be some of that going on.

 

[Basketcase]

Re: Suddenly shuts off..UPDATE

nuther thing to check while you're doing the sending unit is the sock filter on the sender. my first '69 had been sitting for at least 10 years. I got it running in a couple of hours. I backed out of the driveway, and headed out of town. The car died about a mile from home. started right up. I checked the carb,pump,fuel filter, all fine. It would die going up a small hill, but run fine on the flat. I drop the gas tank. The inside looked like the Titanic. The sock filter was all pluged up, so when the need foe more fuel came, it simply ran out of gas.

 

[mannye]

Re: Suddenly shuts off..UPDATE

First of all, thanks for all the help! I am pretty sure I'm going to get to the cause thanks to you guys..

The fuel filter is where it always was, and I recently added a fan shroud, which has dramaticaly lowered underhood temps. This motor used to run so hot, 10 minutes in traffic was enough to send the temp guage all the way to the right, now it can sit all day no problem!

Starter motor is brand new. Old original unit sitting in a box till I have enough money to send it out for resto.

I'm hoping the sending unit helps... the fuel pump replacement made a big difference.

If all else fails, I'll rip out the fancy new electronic ignition and replace the points.

 

[V269]

Re: Suddenly shuts off..UPDATE

Fuel sending unit ? :facepalm: Oh boy, here we go again with someone else having issues with the reading's of a new sender. Hope it work's well for you but if your like most of the rest you will probably have nightmare's too. I give up on mine. :crazy:

 

[mannye]

Re: Suddenly shuts off..UPDATE

Fuel sending unit ? :facepalm: Oh boy, here we go again with someone else having issues with the reading's of a new sender. Hope it work's well for you but if your like most of the rest you will probably have nightmare's too. I give up on mine. :crazy:

Well, since what I have now is the original unit, it can only get better. I just hope I can get away with a pull/replace and not have to go dropping the tank to look for pieces of the old sock!

 

[moparchris]

Re: Suddenly shuts off..UPDATE

Back in the day when I was a mechanic, I used to run across this a lot on GM HEI. The ignition module was getting heat soaked and would do the shut off deal. I think you should look into the Petronix unit as a possible problem. Just a thought.

 

[george68hemirr]

Re: Suddenly shuts off..UPDATE

Back in the day when I was a mechanic, I used to run across this a lot on GM HEI. The ignition module was getting heat soaked and would do the shut off deal. I think you should look into the Petronix unit as a possible problem. Just a thought.

i said this earlier.....my buddies 1968 mustang gt 500 had that set-up and somehow i found a wire chaffed right close to it and was grounding out....it could be just touching something .....so many possibilities

 

[mannye]

Re: Suddenly shuts off..UPDATE

well i give up i am taking it to the mechanic on thursday if the weather cooperates i will post info as it comes in.

 

[mannye]

OK! Mystery solved. THe mechanic was able to figure out that a wire connected to the ballast was loose. So whenever the circuit would open, it would shut off. He tightened it up and the problem was solved.

The "vapor lock" turned out to be the timing, which somehow had been advanced 20 degrees or more, hence the very hard cranking on startup.

He put the timing back at 7 degrees, and now she runs like a top again!

 

[69hemibeep]

OK! Mystery solved. THe mechanic was able to figure out that a wire connected to the ballast was loose. So whenever the circuit would open, it would shut off. He tightened it up and the problem was solved.

The "vapor lock" turned out to be the timing, which somehow had been advanced 20 degrees or more, hence the very hard cranking on startup.

He put the timing back at 7 degrees, and now she runs like a top again!

Good to hear, now drive it