Mechanics

ENGINE DOES NOT CONTINUE TO RUN

1975 Ford F-250 • 130,000 miles

Went to start truck after driving it day before, it turned over and fired but as soon as I let the key go it died. Thought it might be carb so rebuilt it with same results. When you engage starter the motor fires when you let go of key it dies. Think it is electrical. Has electronic ignition with ignition module on firewall, could it be coil or module or maybe starter switch on dash?
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Chrokeva
August 26, 2012.




The module is the most common failure for this condition.

Roy


ASEMaster6371
Aug 26, 2012.
Thanks will be picking up new module today, will let you know.


Tiny
Chrokeva
Aug 27, 2012.
Put on a new module and the truck would not even fire when the starter was engaged, put back on the old module and once again it would fire when the starter was engaged but would die when the key was let go.


Tiny
Chrokeva
Aug 28, 2012.
Check the part numbers to verify the correct module. There are 2 or 3 different ones

Roy


ASEMaster6371
Aug 28, 2012.
The part# on the module on the truck is for a 1976 year ford truck thats why the 75 module would not fire (I guess) ordered a 1976 module, will keep my fingers crossed.


Tiny
Chrokeva
Aug 29, 2012.
I'M GOING WITH AN IGNITION RELATED ISSUE!

JUST SO YOU KNOW A BIT OF HISTORY W/ ME. IMMA JEEP CJ KINDA GUY. MY DAD WAS 100% FORD. THE PICS AND SUCH WERE MADE MOSTLY OF MY JEEP, AND ARE USED FREQUENTLY IN THE CJ 5 & 7 FORUMS, HERE AT 2CAR. CJs DO USE A FORD TYPE IGNITION SYSTEM. SO BEAR WITH ME, IN THAT MY PICS WILL NOT LOOK LIKE YOUR TRUCK.

YOU DID NOT SAY WHAT ENGINE YOU HAVE. MIGHT COME IN HANDY FOR ME!

I WILL GET STARTED NOW!

PIC 1 SHOWS HOW A CJ IS SET UP FOR IGNITION. PAY SPECIAL ATTENTION TO "I" WIRE AND "I" TERMINAL (SORTA THE SAME THING)---TOP RIGHT OF DIAGRAM

"I" FEEDS THE COIL ONLY WHILE THE KEY IS IN THE START POSITION

MY HYPOTHESIS IS: THIS IS THE REASON IT'S "BUSTING OFF" (RUNNING)----THEN WHEN YOU RELEASE THE KEY."I" DIES, AND. THE REGULAR OLE IGN WIRE AIN'T FEEDING IT'S NORMAL JUICE, FROM "ON" POSITION" OF THE KEY!

SO. HERE'S POSSIBILITIES

IF YOU HAVE A RESISTANCE WIRE (LIKE MY JEEP) IT'S BROKE OR GROUNDED

MAYBE YOU HAVE BALLAST RESISTOR (MAYBE NOT), INSTEAD OF A RESISTANCE WIRE (MY RESTORED WILLYS JEEP NOW HAS A BALLAST RESISTOR). THEY COME IN DIFFERENT STYLES, THEY HAVE A RESISTOR COIL INSIDE THEM. THE BALLAST RESISTOR COULD BE BURNED OUT. SEE PIC 2

COULD BE A BAD IGNITION SWITCH

MAY BE COIL RELATED (I'LL GIVE YOU BETTER INFO ON THAT, WHEN I GET YOUR ENGINE SIZE). SEND PLEASE.I WILL THEN BE ABLE TO TELL IF YOUR "CORRECT" COIL NEEDS AN EXTERNAL RESISTOR OR NOT

LET'S SEE IF I'M RIGHT?

DO THIS, FORGET MY "READING". WHAT DO YOU HAVE. PIC 3

JUST A WILDAS GUESS, YOU SHOULD SEE AT LEAST 6 VOLTS ALL THE WAY UP TO WHATEVER YOUR BATTERY HAS IN IT (12 V)

SO. LET'S SAY YOU HAVE NOTHING OR NEAR NOTHING W/ KEY IN "ON"

WE WOULD LACK HAVING CONSTANT VOLTAGE TO THE COIL

DOING THIS. WOULD PROVE EVERYTHING ELSE WORKS. AS LONG AS THERE IS NOT A GROUNDED OUT WIRE.***POSITIVE BATTERY TO POSITIVE COIL***. SEE PICS 4 AND 5

IGN WIRING FROM THE IGN SWITCH IS STILL IN THE EQUATION. IF YOU DO IT THIS WAY.I HAVE A FUSE INCORPORATED INTO MY JUMPER. JUST IN CASE. JUST IN CASE I DON'T WANNA SEE A WIRING HARNESS FRY OR CATCH MY BABY ON FIRE!

THIS NEXT WAY, IS SORTA THE SAME THING. EXCEPT NOW, THE WIRING THROUGHOUT THE SYSTEM IS NOT IN THE EQUATION

SEE PIC 6. THIS IS A LITTLE SAFER, ESPECIALLY IF YOU DON'T USE A FUSE. EVERYTHING GETS BYPASSED

YOUR KEY---SHOULD STILL TURN THE STARTER OVER. WE DID NOT REMOVE "S" WIRE (SEE PIC 1)

REMOVING THE JUMPER FROM THE BATTERY IS HOW YOU WILL KILL THE ENGINE, IF IT STARTS UP AND RUNS

I HAVE NOT TRIED, NORMALLY OUR SOURCE FOR GETTING WIRE DIAGRAMS DOES NOT GO BACK THAT FAR. EVEN THEN I WOULD NEED YOUR ENGINE SIZE TO SEARCH

PICS 7 AND 8 ARE WHERE MY PICS CAME FROM

IF IN DOUBT OR NEED AN EXPLANATION. DO REPLY BACK. BEFORE YOU BLINDLY JUMP IN!

THE MEDIC


CJ MEDEVAC
Aug 30, 2012.
PS

GIVE YOUR TEST RESULTS BEFORE YOU START THROWING PARTS AT IT!

I CAN KEEP GOING. FOR AWHILE ANYWAY.I NEED A "DIRECTION" TO FOLLOW. NEED INFO I REQUESTED AND YOUR RESULTS

THE MEDIC
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CJ MEDEVAC
Aug 30, 2012.
I ALSO MEANT TO THROW IN

IGN MODULES USUALLY HAVE A COLORED PLASTIC DEAL WHERE THE WIRES ENTER

MY 258 6 CYLINDER USES A "BLUE" ONE---SO DOES MY DAD'S '76 FORD F-150 W/351 WINSOR.I OBTAINED THE ONE IN THE PIC (AND SEVERAL MORE) FROM A SALVAGE YARD THAT I FREQUENTLY VISIT.

ALL OF THEM WERE OFF OF VARIOUS FORD VEHICLES. SELDOM FIND A CJ IN A SALVAGE YARD

THEY JUST "GAVE" 'EM TO ME.

I KEEP IT, A NEW FUEL PUMP, A COIL, THE LINK TO MY CLUTCH ARM IN MY CONSOLE, BETWEEN THE SEATS OF "MR. JEEP". ALONG WITH ABOUT 100 LBS OF TOOLS AND OTHER EQUIPMENT!

I'M GOOD, UNLESS A MAJOR ITEM SHELLS OUT

THESE ARE EZ. STUPID ITEMS THAT HAVE LEFT ME STRANDED, THAT I COULD EZily INSTALL IF I HAD POSSESSED THEM IN THE PAST

LUCKILY, SINCE I HAVE BEEN CARRYING THEM.I HAVE COME UPON 2 OTHER CJs ON THE SIDE OF THE ROAD. ONE USED MY SPARE FUEL PUMP. THE OTHER GOT MY EXTRA MODULE (I WAS GENEROUSLY REWARDED FOR INSTALLING BOTH!)

OF COURSE I REPLENISHED MY STASH!

NOTICE, I INSTALLED EACH AND EVERY USED MODULE ON MY JEEP FOR A "REAL WORLD" TEST. THEN WROTE ON MOST, THAT THEY WERE GOOD

THE MEDIC


CJ MEDEVAC
Aug 30, 2012.
The engine is a 360. Bought a module for it but did not work would not even fire, I took the part# off the old module and finally found out why the module on the truck is for a 1976, why? Who knows it might of been changed out years ago or when manufactured. Have a new module coming in today will probably wait to get module before start testing but who knows may print all this stuff out and head out. There are so many people with testing advise I'd like to see a list from start to finish at testing, Ive gotten so much info some the same some different, maybe from turning on the key and seeing if you have power at the coil but doesn't the power goes through the module before it gets to the coil? Things like that. Ive played with motors for a long time but electrical has always been my shortcoming. Thanks


Tiny
Chrokeva
Aug 30, 2012.
I RECKON I SHOULD THROW THIS IN TOO!

I MEANT TO IN THE BEGINNING

IF YOU HAVE NO, OR VERY LITTLE VOLTAGE AT THE POSITIVE SIDE OF THE COIL WITH THE KEY IN THE "ON" POSITION. LETS TRY THIS 1ST!

I FEEL SURE YOU HAVE GLASS FUSES, AS I DO IN MY '77 (MR. JEEP)

ONE WILL MOST LIKELY BE FOR THE IGNITION. IF IN DOUBT, CHECK 'EM ALL

EVEN IF THE FUSE(S) IS/ARE GOOD A LITTLE SANDPAPER ON THEIR ENDS, AND MAYBE SOME SANDING OR SCRAPING OF THEIR HOLDERS MIGHT INSURE A GOOD CONNECTION.A DAB OF DIELECTRIC GREASE ON 'EM WON'T HURT EITHER

YOUR TRUCK IS 37 YEARS OLD. MY 36 YEAR OLD JEEP MIGHT BE MORE WEATHER EXPOSED.I HAVE HAD MY FUSES AND HOLDER GET A GRAYISH-WHITE LIGHT CORROSION ON THEM AND SOME STOPPED WORKING.

THE SAME GOES FOR THE FLOOR DIMMER SWITCH DAMPNESS AND CORROSION WILL CAUSE THE HEADLIGHTS TO BLINK OFF AND ON (EVEN MELT THE CONNECTOR) DIELECTRIC GREASE IS EVERYBODY'S FRIEND!

SHOULD THAT NOT DO THE TRICK, CONTINUE WITH THE MORE INVOLVED TESTING, SO WE CAN NARROW IT DOWN

THE MEDIC


CJ MEDEVAC
Aug 30, 2012.

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