Truck problems

[BKW]

The three 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.

Since the module only fails when it overheats (Ford techs refered to DuraSpark on vehicles of this vintage as NeverSpark!), taking the little charmer to an autoparts store to be tested usually doesn't work, unless it has failed all together.

Inside the dizzy is the stator (aka magnetic pickup coil). The symptoms can be exactly the same as the module.

Most autoparts stores in today's world sell modules that are made in China CRAP! Some of these are defective right oughtta the box.

Replace with a genuine Motorcraft module, ditto for the stator.

Look on the module...above where the wires feed out for the colored plastic square, which ID's which module you have...as there were several different types used 1976/79.

The most common is the blue module, but if the vehicle was sold new in CA, the module might be red, blue, or brown.

The same stator (D4PZ12A112A-Motorcraft DU1A) was used 1974/79 on all V8's (except 1979 LTD's w/EEC & 351W's sold new in CA).

 

[Alvin in AZ]

Cool post Bill.

I want to add the way my '75 Dura Spark 1 ignition module acted and
late one night me and Dennis helped a guy over on F'in'TE with an old
Dura Spark 1 like mine ...that had the exact same symptoms as mine.

Acts like the coil's ballast resistor is gone and/or intermittent.

Everything sounds fine until you let off the starter but the engine dies
when you let the starter off. See it?

Intermittent enough that mine never left me stranded anywhere tho!

Also I think I killed the original back in '79 by nursing a bad battery. :/
I didn't feel like I had $25 to replace the battery right then, so spent
$109 on an LX-201 module? Plus a battery! LOL

One more thing I want to add is how good the Standard Motor's Blue
Streak module I replaced the original with, worked perfect from '79.
It's my spare now having bought another SMP LX-201 from Rockauto
for $24. Price of some stuff has actually gone down.

Alvin in AZ
'75 F150 360FE + T18 special ordered it when I was 21 and it's settin'
out in the driveway right now with a used washer and dryer in it right
now and ready to go to Mexico.
http://www.panix.com/~alvinj/file12/module.jpg

 

[Alvin in AZ]

The instructions for replacing a Dura Spark ignition module in Ford's
Shop Manual is the same that comes with the Stand Motor Products
ignition module. Wonder who wrote it? People at Ford, SMP or both?

Anyway it amounts to 1) electrically checking the vehicle with a volt/
ohmmeter to be sure the trouble is-not in the vehicle and-so ruin the
new module 2) plugging in the module. LOL

Those are the exact same instructions Ford uses to "test" to see if
a module is bad. "swap it out with a new one off the shelf" but only
-after- making sure the vehicle is not going to ruin the new one.

Alvin in AZ

 

[gsxr1238]

He's already aware of this.

The problem was the test light became unattached

It has been determined he has to be DRIVING the vehicle to where it failed

It doesn't fail sitting in the driveway

If the test light was connected correctly as described,it should have been flashing.This shows that the field is collapsing in the coil.It also shows the signal from the pickup to the module to the coil is functioning at the time.A constant light connected to the tach test side would show as a problem upstream of the coil.He has since stated that the failure has also occured in the driveway.

 

[Mil1ion]

NOT on the + Terminal where it is supposed to be.

We have to determine if it is a PRIMARY ignition between the key and coil problem first..then move to the breakerless system

anything between the key and coil can happen.

One part of the system at a time.

 

[gsxr1238]

Tach test side(negative)!That is the primary side.Secondary occurs out of the coil to the distribitor cap.

 

[Mil1ion]

Yes but the idea was to concentrate on one area at a time.

Example:
Q: Please tell when there is no tach signal if the problem is in the key,ECM, Distributor ?

I say it again, we are trying to trouble-shoot things in ORDER not start half way through the circuit.

With the Ignition circuit it starts at the Ignition switch in RUN position

With no Tach signal how do you know the problem isn't the switch ?


Again, we are doing the process of elimination procedure ONE step at a time.

To the OP, let me know when you have tried the first step and got the proper result we were looking for

 

[gsxr1238]

The answer to your question is when there is no power at the positive side of the coil.I will grant you that I stepped around a lot of the trouble shoot procedure you want him to look at.I apologize.I won't argue with you about the way this ignition works,or the tendencies of the failings of the probable suspects in this ignition system.I will take my seat and watch.

 

[blacksnapon]

Remember during the process of replacing the magnetic pickup, the tendency to break the gear? Then you find out that you couldn't buy just the gear, you had to buy the whole distributor. Been there, done that! I bought a puller to remove the gear and install it, then I've never had to use it again!

The three 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.

Since the module only fails when it overheats (Ford techs refered to DuraSpark on vehicles of this vintage as NeverSpark!), taking the little charmer to an autoparts store to be tested usually doesn't work, unless it has failed all together.

Inside the dizzy is the stator (aka magnetic pickup coil). The symptoms can be exactly the same as the module.

Most autoparts stores in today's world sell modules that are made in China CRAP! Some of these are defective right oughtta the box.

Replace with a genuine Motorcraft module, ditto for the stator.

Look on the module...above where the wires feed out for the colored plastic square, which ID's which module you have...as there were several different types used 1976/79.

The most common is the blue module, but if the vehicle was sold new in CA, the module might be red, blue, or brown.

The same stator (D4PZ12A112A-Motorcraft DU1A) was used 1974/79 on all V8's (except 1979 LTD's w/EEC & 351W's sold new in CA).

 

[Mil1ion]

The dizzy on my 77 460 went out

I left the original reluctor on the shaft and just replaced the pickup.

The engine still runs like a champ

 

[thatsrealnice]

Hey guys,

Thought I'd update everyone. It's been 20 below here, so not many opportunities to work on the truck, and still hadn't really figured out what was going on with it. So finally just had it towed to a shop, and they looked it over, and it was the fuel pump, the diaphram was shot, and gas was getting into the oil. They also adjusted the float in the carb, which I hadn't adjusted correctly when I rebuilt the carb. So drove it home from the shop, and ran really well. Thanks for all the suggestions, I'm sure I'll be back the next time I run into an issue.

 

[LEB Ben]

Glad everything got worked out...and it shouldn't have set you back too far.

 

[fatherdoug]

Hey guys,

Thought I'd update everyone. It's been 20 below here, so not many opportunities to work on the truck, and still hadn't really figured out what was going on with it. So finally just had it towed to a shop, and they looked it over, and it was the fuel pump, the diaphram was shot, and gas was getting into the oil. They also adjusted the float in the carb, which I hadn't adjusted correctly when I rebuilt the carb. So drove it home from the shop, and ran really well. Thanks for all the suggestions, I'm sure I'll be back the next time I run into an issue.

It's always nice to find out the solution to the problem. Thanks for posting.