Motor keeps dying on me

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Rox Crusher
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Motor keeps dying on me

Post by Rox Crusher »

Ok, it used to be very infrequently (say once a month or so) but has happened three times today already

It seems to be an electrical issue as it dies without any stumble or advance warning. Doesn't seem to matter if engine is cold or hot.

I can slap it in neutral, fire it right back up first attempt, slap it back in gear and go.

I haven't tested a darn thing so I am hoping that a guru or two will tell me what the most likely cause is so I can replace the part before Saturday.
1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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sbolt19
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Re: Motor keeps dying on me

Post by sbolt19 »

Have you looked at the power wire on the ignition? If it's loose in any way it can do that. You are still carb'd right? What about looking in the dizzy to see if the condenser wire is still screwed down. Push the coil wire back on nice & tight on both the coil & distributor cap. Check the connections on the ground cable on your battery. Make sure that both battery cables are in good shape. Try those.
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Re: Motor keeps dying on me

Post by Viperwolf1 »

Does anything else die (radio, gauges, etc) when the engine quits? If not it wouldn't be a battery cable or ignition switch problem.
Shawns Fords
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Re: Motor keeps dying on me

Post by Shawns Fords »

What type of ignition system is in it? Does it have an electric fuel pump? Does it get more frequent when it is hot outside or cooler? I would check all connections as previously stated before going any further.
Viperwolf1

Re: Motor keeps dying on me

Post by Viperwolf1 »

69 Bronco 69 wrote:What type of ignition system is in it? Does it have an electric fuel pump? Does it get more frequent when it is hot outside or cooler? I would check all connections as previously stated before going any further.


It's a '77 duraspark.
Viperwolf1

Re: Motor keeps dying on me

Post by Viperwolf1 »

Checkout the ignition harness connectors. It's common for them to crack.
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Rox Crusher
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Re: Motor keeps dying on me

Post by Rox Crusher »

Viperwolf1 wrote:Does anything else die (radio, gauges, etc) when the engine quits? If not it wouldn't be a battery cable or ignition switch problem.


sorry, should have been more explicit.

I am pretty certain that the chassis elecrical (radio, gauges, etc) remain functional.

Battery cables are in good condition and connections are nice and tight.
1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Moab Mike
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Re: Motor keeps dying on me

Post by Moab Mike »

It's your rig telling you to put that damn EFI in spit
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Re: Motor keeps dying on me

Post by Shawns Fords »

Viperwolf1 wrote:
69 Bronco 69 wrote:What type of ignition system is in it? Does it have an electric fuel pump? Does it get more frequent when it is hot outside or cooler? I would check all connections as previously stated before going any further.


It's a '77 duraspark.

That would be my first suspected item. My 78 and my 76 F series used to give me signals like this in the summertime. As it got hotter it got more frequent, then when you least expected (usually on a long drive) it would quit all together. another possibility is a weak ground connection somewhere.
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ZOSO
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Re: Motor keeps dying on me

Post by ZOSO »

I'd check all the conections on the ignition switch. And all the connections on the duraspark system. My bronco just up and quit one day and what the issue was actually too much dialectric grease in one of the connectors.
Rob

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Re: Motor keeps dying on me

Post by Shawns Fords »

Check your rubber fuel lines for any leaks, if it is sucking air in through a line you wont even see a leak, but it sucks in air when driving, dies then will restart once stopped. Just another thing to check.
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Rox Crusher
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Re: Motor keeps dying on me

Post by Rox Crusher »

Please keep the suggestions coming...........

Given that I have been fooling around under the dash installing CB radio, upgrading wiper switch, and cig lighter......I am thinking the ignition switch wiring could be the culprit.

I checked the connections and they are all tight but maybe a fragile wire is giving up the ghost.
1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Moab Mike
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Re: Motor keeps dying on me

Post by Moab Mike »

Rox Crusher wrote:Please keep the suggestions coming...........

Given that I have been fooling around under the dash installing CB radio, upgrading wiper switch, and cig lighter......I am thinking the ignition switch wiring could be the culprit.

I checked the connections and they are all tight but maybe a fragile wire is giving up the ghost.


So this started last weekend?
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Rox Crusher
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Re: Motor keeps dying on me

Post by Rox Crusher »

76fordbronco wrote:
Rox Crusher wrote:Please keep the suggestions coming...........

Given that I have been fooling around under the dash installing CB radio, upgrading wiper switch, and cig lighter......I am thinking the ignition switch wiring could be the culprit.

I checked the connections and they are all tight but maybe a fragile wire is giving up the ghost.


So this started last weekend?


nope, was happening long before then but very rarely
1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Re: Motor keeps dying on me

Post by Viperwolf1 »

The pdf I posted above will give you some things to check out.
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Rox Crusher
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Re: Motor keeps dying on me

Post by Rox Crusher »

Viperwolf1 wrote:The pdf I posted above will give you some things to check out.


ok, thanks Viper

did I overlook your post with the pdf or did is just now load to the thread ?

weird
1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Jesus_man
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Re: Motor keeps dying on me

Post by Jesus_man »

Check your plug wires too, make sure they aren't grounding out against your headers or something. That's a shot in the dark as it seems you are pretty well handled, but easy to check.

J.D.
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
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Rox Crusher
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Re: Motor keeps dying on me

Post by Rox Crusher »

UPDATE:

I haven't had time to do any testing of the wiring, etc other than to ensure that wiring connections are tight.

Happened again this morning when I left the house.........was only going 10 - 15 mph, engine cold (but running smooth as always), and it died.

This time I didn't slap it in nuetral or try to restart.

I looked to make sure the dash lights and heater fan were working and suddenly it fired back up on it's own.

It was 1 - 2 seconds max between dying and restarting.

Any more ideas with this new information ?
1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Jesus_man
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Re: Motor keeps dying on me

Post by Jesus_man »

Really sounds electrical. Got to be ignition related.
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
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sbolt19
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Re: Motor keeps dying on me

Post by sbolt19 »

My first thought is ignition related too. I'm gonna think out loud for a few so bear with me.....
What about the starter solenoid? Have you ever replaced that? If a coil goes bad (I've never had one go out) it won't keep firing up, but if the starter solenoid goes out, sometimes it will cut in and out. A rap on it with a screwdriver handle sometimes takes care of it. I would say it has to be a loose wire somewhere. Check both the + & - wires on the coil to be sure the connection is good. It has been so long since I have had electrical issues, I forget what to look for and where to start
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Jesus_man
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Re: Motor keeps dying on me

Post by Jesus_man »

Good news is that with a carb motor, there isn't nearly as much to track down and trace.
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
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Gunnibronco
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Re: Motor keeps dying on me

Post by Gunnibronco »

zillacon wrote:Image



My first thought:
Image

If you go out to your garage and say "Show me!", and it fixes itself be afraid.
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Re: Motor keeps dying on me

Post by dans69bronco »

just a thought i don't know if you have thought of it but i once had someone put some trash in fuel tank it would run fine tell the piece of hard plastic would suck down over outlet motor would die i would turn key off to restart it would float up and would start right back up took me almost a year to figure that one out. good luck!
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