OK, I'm about on my last straw with this truck.

Some of you may remember me on here a few months back, I was having major sputtering problems when I was taking off from a dead start. Fixed that, now I'm back. >_<

Here's the background; I fixed my old problem by replacing the distributor. Now the truck doesn't sputter during take off *PHEW*. So I drove it for a few days, no problems. Then one morning it wouldn't start, cranked over but did not fire; No big deal, got in my Chevy and drove off to work. Came home later on, 1 pump of the throttle and cranked her over, fired right up.

Ever since then, I have been having problems with the truck. Here's where I'm at right now:
- Carburetor Backfires
- Once engine does start, it will randomly die. No warning or anything, just out of the blue stalls out (Idling, after running for a minute or two).
- Sometimes when cranking over the engine, it will crank over one time, hesitate, and then crank like it should. (Think of how slow a truck will crank with a dying battery, that's what it does at first).

Random information that might help diagnose my problem:
- Timed at 12 degrees BTDC after replacing distributor. Re-timed to 6 degrees BTDC after these problems started.
- New Edelbrock 1406 carburetor with Fuel Pressure Regulator.
- Vaccuum advance plugged into passenger port of Carburetor.
- Timing jumps up to 30-40 degrees when I give it throttle, but comes back down to 6 when idling.
- Engine is completely stock besides a 4 barrel intake and the Edelbrock carburetor.

I might not reply asap to any thoughts / solutions, as I am in the process of moving into my own house! It has a 2 car garage, and that's where she's going once I get all moved in. So it might take awhile for feedback on suggestions, but I will definitely try them out.

Thanks!

 

Have you tried a new duraspark box?

 

I have not, unfortunately. Thank you for suggesting that, though! I actually have 3 of them in my garage that my Grandfather gave me. He used to have a 73-79 hobby and he gave me some parts when I got this truck.

Anything I should be weary of when trying different boxes? I don't know the years or any information at all of the trucks they came off of.

 

Dura spark boxes are identified by the color of the plastic grommet that surrounds the wire bundle where it goes in the box. The most common color is blue. You can swap like colored grommet boxes without problem. 74/75 boxes are each one year only boxes and don't interchange.
You also might want to do a load test on you battery.

 

check your voltage at the coil/ing. box and make sure you have good grounds(batt>engine>frame>cab)
also check the key switch for loose conection plug and wore out switch(lots off keys hanging/swinging will wear the contacts
hope this helps and doesn't overwhem

 

I swapped out the ICM on the truck with one I had laying in my garage. Fired right up with the new ICM. Let the truck warm up, re-checked the timing and it said it was at about 24 degrees BTDC? Not sure if that was because I timed it with the faulty ICM box or what? Anyhow, I re-timed it with this new ICM box at 12 BTDC, and now she runs like a beauty. Haven't gotten the ability to drive it on the street yet (Single car driveway and 4 vehicles... Yeah) but I am pretty anxious to! Tomorrow will be the day.


Thanks all for input, really really appreciate it. I was getting so pissed off that I was about to sell the damn truck. Glad I didn't.

 

how many miles on engine? sounds like timing chain.

 

Engine only has 56k miles on it; doesn't burn oil and I love it. Runnin full synthetic in it.
I was thinking timing chain too, not to say that's out of the picture now since I still haven't tested the truck out to make sure all is 100% well.

I still might put a double roller timing chain in it when I move into my house, it probably wouldn't be a bad investment.

 

low miles shouldnt be chain. had starting problems with mine somtimes after heavy rain start engine at night and see what arcing under hood.

 

might be worth changing the coil too my 74 is having problems dying but still had the original coil on it up till last week. my next step on that truck is the fuel filter but i cant get the can off of the pump.
take your old module to a parts store and have them test it several times and see if it will test bad i would like to know if your module really was bad or not?!

 

Possibly a slipped harmonic balancer issue.

 

1U2Z-12A199-AA (replaced D6AZ-12A199-A, D8VZ-12A199-A, D9VZ-12A199-A) .. Ignition Module blue (Motorcraft DY-893) / Available from Ford.

MSRP: $120.84 // FTE sponsor tousleyfordparts.com pice: $73.11.

Applications: 1976/97 myriad FoMoCo vehicles.

The 3 step scenario of a failing DuraSpark ignition module:

1) Module overheats, engine dies. Module cools down, engine restarts almost at once.

2) Module overheats, engine dies. Module cools down, engine restarts in an hour...or so.

3) Sooner or later, usually sooner, the module overheats, BURNS OUT. Now the engine will not restart.

Engine heat, especially radiating from the V8's red hot left exhaust manifold, is the mortal enemy of these modules.

When replacing the little charmer, use some washers to space it further away from the left fender inner apron. The more airflow, the better.

Taking the module to an autoparts store to be tested: Since it's cool, it will test OK, unless the little charmer has burnt out.

When Ford techs replaced modules in 1974/79 V8 vehicles, they also replaced this little charmer:

D4PZ-12A112-A .. Stator aka Magnetic Pickup Coil (Motorcraft DU-1A) / Available from Ford.

MSRP: $86.56 // FTE sponsor tousleyfordparts.com price: $52.37.

Applications: 1974/79 V8 FoMoCo vehicles except 1979 LTD/Grand Marquis 351W w/EEC / Misc 1980/88 FoMoCo vehicles.

 

as far as the timing chain, i thought mine would be okay with only 80000 original miles, but i have found that my driving habits are very hard on timing chains in every vehicle ive had esp with a standard transmission, mine was stretched pretty good! i put a new chain back on the factory gears since i found this on accident just replacing the timing cover seal