Okay here's the problem. 84 F250 300 inline... All the smog and catalytic has been striped.. Stock 1 barrel carb and Duraspark II (which I'm sure is not original).. Motor runs great except at cold start I'm getting a slow struggling sound as if out of time.. After a couple of turns it will turn over normally and fire right up..After engine is warm I don't seem to have the problem..Timing set at 10 BTC.. The module was replaced With a Wells only as a preventative measure during a routine tune up. The problem only started with the new module so obviously the old one was put back in..Problem solved..... Replaced Wells with a new Motorcraft... Same problem.. All units are blue grommets...Could this thing be retarding during startup???

 

 

Well.... a DSII module is supposed to retard timing when the starter is cranking.
Advancing the timing is what makes the starter labor while hot cranking.

Where is your ignition timing set now? (are you sure the damper has not slipped)
Considered jumping the plug to see how it acts without the white wire?
Are the wires crossed at the plug, like they should be?

 

Had kind of a similar incident recently. The 30 year old Duraspark unit finally died in my truck (found this out trying to start it one day). Threw in a Wells p.o.s. and it fired right off. Called the local Ford dealer and order a new Motorcraft one. Went to Napa and got a new USA made coil right away too.

When I put the new stuff in, everything was great, or so I thought. When I went to restart it with a hot engine, it cranked really hard, then eased up. I'm running the gear reduction permanent magnet starter. I have not tried it again to double-check. My base timing is at 10* too.

The new Motorcraft module is a lot smaller than the old one. I'm wondering if they took out the spark retard in the newer units? With the old Motorcraft module, I never had a problem restarting hard like that.

 

Do I understand the situation correctly? Everything was fine with existing module A. Replacements B and C cause trouble. If you reinstall original module A, is all good again?

If so, quit changing modules for one thing... If nothing else, this would confirm all interfaces (wiring, coil, distributor pickup) are good.

If you really have your heart set on replacing that perfectly good module, you've either got two defective or incorrect replacement modules. How are you determining the part number? I'm not well versed in DS variations, but maybe you're getting the wrong model.

 

*ALL* DSII modules*should* incorporate spark retard (*and* this is happening *cold* not hot)
This is part of their function.
Retarding the timing a few degrees while cranking should not make the starter struggle in any case.

I use the NAPA Echlin TP40 module and can see (with a timing light) that it indeed retards the timing when power is applied to that lead

Makes me wonder if the engine is too tight until it gets some heat in the block.
​​​​​​​But you would only expect to see that on a new engine.

.

 

I would go back to the box that works as there is no need to replace it if it works.


Now if you think it is a timing issue an easy test is to back the timing off to TDC and see if you get the same thing.


I say it is a voltage thing for the slow crank when cold.
I would do a voltage drop test on all the batt cables as any could be bad.
Better yet I would just replace all the cables cause who knows how old they are.


And NO you can not look at them to see if bad or not as they go bad inside with corrosion.
Dave ----

 

Check your timing while this is occurring right after a cold start and see if it is less than you set it to. If retarded be sure RPM is the same as when you set it, and that mechanical advance mechanism is clean, lubricated, moves freely, and fully returns. It should be fully returned to no mechanical advance at your idle RPM.

With no other facts to go on I'd be more inclined to say you need to adjust the choke if this is only on a cold start. DSII only retards timing while cranking, if the crank retard was engaged your starter would not be disengaging.

 

How is checking timing after it starts and is running going to tell anything?
Oh wait I are checking for stuck weights right?

Dave ----

 

Don't go down rabbit trails. The problem is obvious, it's the module. Put old in, problem is gone.

Is it something with the wiring plug on the new module? The circuitry in the new module? I am not sure on that. You could go to the junkyard and find a older motorcraft unit and see if it works correctly. So long as it's a blue module, it doesn't matter if its a car, truck, 4 cyl, 6 cyl, 8 cyl, Lincoln, Mercury.

 

OP suspects timing is the issue of his rough running after a cold start. While I doubt that is the case, it is easy to confirm or eliminate by checking the timing after a cold start while it exhibits the symptom.

I mentioned cleaning and lubricating the mechanical advance and verifying its functionality as if it hasn't been done it's due for a servicing after 30+ years.

As a side note, I had a Ford duraspark unit fail on me once in a decade of driving 80-86 trucks. It rapidly died with a brief period of randomly misfiring and stalling then no spark at all after a few minutes of erratic behavior. Hitchhiked home and grabbed a used spare that was an aftermarket unit (blue plug) and has worked fine for almost 4 years now with that.

 

Thanks for all the great input... This is only my first Ford as I am generally a GM and Mopar type however I really love the square look of my 84....


Checked timing today and it was so far retarded that it barely was readable under strobe.. I had to get a new timing light as mine had been lost in a divorce shuffle.. Went on line for a $20 Chi-Com POS and quickly threw it in the trash.. $35 later got a 30 year old Craftsman on line (worked like a champ...Made in USA..) and set timing to 10* BTC...tomorrow will try a cold start test.. By the way all of the mentioned boxes are blue grommet. I think all blue boxes are interchangeable for all years and dizzies?????

Anybody here deploy to the sand box????

 

Good to hear you found something that was off and hope it fixes the cold start/run issue.


Nothing on you but I am surprised some times on how many say "this is my first Ford coming from xxx or xxx".


A motor, trany, brakes, rear, etc. works the same in everything. Yes there may be little tricks how to do this or that but for the most part it works the same.


Fatten up the carb on ANY MOTOR and it will run rich. Run any auto trany low on fluid and it will not work as it should.
Run brake pad & shoes low on lining and they can/will make grinding noise, have a low pedal and brakes that don't work as they should for any brake system.


So just because it is a xxx and not what you normally work on you go about finding what is wrong the same way.


Let us know how you make out on the cold run part.
Dave ----

 

5432 , nice looking truck, I also had the hard timing crank up ,but after a hot engine run.Go to store cut off truck get back in and it seemed like it wasn't cranking .This had been doing this sporadically ever since I switched to the duraspark 2.At first I dismissed it for not having the clutch depressed Etc... This was only after a hot engine run. Recently swapped the duraspark over to the msd 6a and problem solved ,Good luck TR

 

Yes, all blue grommet modules are DSII and should be interchangeable.

There were other similar appearing ignition modules with red, yellow, brown (and I think green) bushings.
these are DSI, Cali emissions, high altitude, etc...

Glad it was something as simple as the timing being way off.
I'm also glad you weren't faced with a frozen distributor.


​​​​​​​Thank you for your service to our country.