Cuts off on its own

[Ghost Rider]

I will be driving along and it just quits. Wait 15 to 20 min. fires right back up then will do it again. Please Help love the truck and want to fix it

[BroncoJoe19]

What year is your Bronco?

[jbgood]

I'm having the same problem with my 86. I haven't found out what it is yet but it only happens when the outside temperature is at or above 70 degrees. It sat on the side of the road last night because it reached 74 outside. I picked it up this morning and came on in to work. Will have to leave it here at the end of the day as todays temp. will be in the lower 80's. I'm thinking something to do with the fuel pump overheating maybe. Don't really know yet. I just bought the thing and haven't bought a manual for it yet.

[strongoak]

Ford had problems in the 80's with ignition switch separation. Would check ignition switch.

[BroncoJoe19]

I'm not sure if they had an early duratec ignition in the '86s or not, but a common symptom is that the engine would start and run fine, but shut off like someone reached over your shoulder and turned the key off. After sitting a while it would start right back up.
The problem was often the pick up coil inside the distributor. It failed once it got hot, but was fine when it cooled back down.

I'd suggest this.
Pick up a spare spark plug, and throw it in your center console. Next time she fails, pull a plug wire, hook it to that new plug, and ground the plug, have your partner crank the engine and check for spark. If no spark, leave the key turned to ON/RUN, and check for 12 volts on the bat side of the coil. If you have 12 volts, suspect the pick up coil. If not, then perhaps the ignition switch as mentioned above.

[blue beast]

Grab a can of keyboard duster and the next time it happens turn the can upside down
and spray the TFI module for about 10 seconds and try restarting, If no go then remove
the cap and rotor and spray inside there for 3-5 seconds, try to restart if no go then
move on down the line of electric components. When you find the one that allows it
to start you found your heat related failure component and you can replace that one.
It's always wise to let it happen again and spray only that part just to double check!
It's called Cryodiagnostics and they sell a can of it for alot more money then the duster
and the only difference is the prograde stuff allows you to spray the freon out without
turning the can upside down. My buddy ran his Vitara for 6 months by doing this only
because he couldn't afford the part and it didn't take much to cool it for another hour
of running!! If you have the tfi module and it has been on for awhile you can get
some silver heat sink paste and remove the tfi clean it and the disty good and apply a
good layer on it and reinstall. Ford got hit with a class action suit for these heat failing.
I didn't bother cashing my whopping $4.00 check!!

[1 wrench]

Originally Posted by Ghost Rider

I will be driving along and it just quits. Wait 15 to 20 min. fires right back up then will do it again. Please Help love the truck and want to fix it

I had the same problem while rebuilding a 1986 Bronco II 5sp 4x4. Ensure you disconnect the negative battery terminal first. First I would remove the TFI ( ignition Control module) located on the back of the distributor. . (it's a little rectangular box and takes a 5.5mm socket to remove it. Take it to Auto Zone or another parts store to get it tested. If it tests good, reinstall it and replace the temperature control sensor located behind the top radiator hose. This sensor is responsible for the metering of fuel based upon the temperature of the engine. If it is sending a false reading to your on board computer it will shut down as you described.

I hope this helps, I almost pulled all of my hair out over the same problem. Good luck.

1 Wrench