Pinto Electronic Ignition

[daveghunt]

About 20 years ago, on one of my many visits to the local scrap yard, I acquired a bosch distributor, 2 control modules and most of the associated wiring loom form a Sierra.
These have been languishing at the back of the garage ever since, even surviving a house move and clear out.
After seeing 'Twinstacks' post on pedal rubbers and remembering the ones I had bought and never fitted, a search discovered the rubbers and the ignition parts.
Being in lock down I decided to have a go at fitting this system, but keep the option of returning to the reliable working points system.
Main problem is the wiring loom. As I had a loom the wiring between the control module, coil and distributor where obvious, although there appeared to be different diagrams posted on line.
(moral : don't trust everything you see on line)

Diagram 1
From a kit car site (distributor and coil wiring reversed)


Diagram 2
Diagram by Stephen Middleton, was amongst some paperwork I have kept for reference.
This appears to be as my loom but the wire colours differ.
The module is also viewed from the underside.

I'm sure somebody out in the club must have carried out this conversion, I have one out standing question
Why are there two feeds to the module (from diagram 2) Black/green to the starter motor and black to the coil / ignition switch?
I would be grateful for any advise before I continue.
Please don't advise fitted a after market power spark system, half of the enjoyment of owning the Berlinetta is resolving issues as above.

Dave H

[Ye Ol Ripper]

Re: Pinto Electronic Ignition

Hi Dave
With regard to the following question:

"Why are there two feeds to the module (from diagram 2) Black/green to the starter motor and black to the coil / ignition switch?"

When you are cranking the engine using the starter motor the voltage decreases to the coil from 12v down to eg 8v .
On conventional systems the ballast resistor system would allow a higher coil voltage during cranking .
I would therefore assume that with this system to maintain the 12v to the coil while cranking the output from the ignition amplier module feeds the coil at 12v.

I recall on the Sierra that there was a braided earth wire on the distributor that fitted on the tag. That is important as I attended a breakdown in the late 80's and that wire was broken and did cause loss of spark until I replaced it.

Iirc the Amplifier was in the Sierra's engine bay and that was earthed through the fixing screws/bolts. Therefore you might(not certain) also need to run an additional earth wire to the casing of this module to the fixing screw/bolt.

[daveghunt]

Re: Pinto Electronic Ignition

Thank you for your information.
I had noticed two earths on the distributor one through the loom plug (position A on attached photo)
and a separate tag (position B on attached photo). to me this seems belt and braces, but I'll bear in mine your experience.
As to the module earth, the brown wire does earth to the module body (checked with meter) I am going to mount it to the engine mount bracket as suggested, this is the most convenient position relative to the other components, so it should earth through its self.
I also note that this is an important heatsink, so I am investigating possibly using some thermal transfer paste.

I do not consider my self a electronic expert, being able to follow a wiring diagram without understanding the operation of transistors or microchips. I learnt that all wires contain smoke, if you put the wrong two together the smoke escapes!

[andyf]

Re: Pinto Electronic Ignition

To be honest if you have a standard Pinto distributer it is easy enough to get an accuspark module and fit it. I have one and it works really well and does not need anything other than the module that fits in the distributor.

[Ye Ol Ripper]

Re: Pinto Electronic Ignition

If I recall correctly the Sierras had a metal shroud around the distributor cap with the Bosch distributors.
The earlier Pinto's on Points didn't have this.

[philcoyle]

Re: Pinto Electronic Ignition

Nothing wrong with your memory, a shield to stop interference with the Hall Effect electronic ignition .

[daveghunt]

Re: Pinto Electronic Ignition

Interesting, I have found this photo of a distributor with a shield?
The only other reference I can find is in the supplement section of a Sierra Haynes manual, that suggests it was fitted to fuel injection models.
(a lesson here to look at the supplements)
Which also have a more sophisticated control module.

The photo does show the braid earth mentioned in an earlier post.
As I haven't got this part I'll discover what happens without it.

[philcoyle]

Re: Pinto Electronic Ignition

If you want to extend your knowledge about EFi dizzies, the early EFi had the control module bolted on the body of the dizzy with fatal results in very warm parts of USA , the module would overheat and break down and the engine would stop not a nice thing to happen in the fast lane. Ford was sued numerous times and changed the design, the result was that short lead connected to a longer one to the control module which was now fitted to the inner wing on a heat sink , result no more nasty accidents, I moved my module onto a heat sink and fitted it on the bulkhead, its been working faultlessly for over 18 years.

[Ye Ol Ripper]

Re: Pinto Electronic Ignition

Nothing wrong with your memory, a shield to stop interference with the Hall Effect electronic ignition .

My long term memory is great , short term is not as good

[Ye Ol Ripper]

Re: Pinto Electronic Ignition

Interesting, I have found this photo of a distributor with a shield?
The only other reference I can find is in the supplement section of a Sierra Haynes manual, that suggests it was fitted to fuel injection models.
(a lesson here to look at the supplements)
Which also have a more sophisticated control module.

The photo does show the braid earth mentioned in an earlier post.
As I haven't got this part I'll discover what happens without it.

Yes that the braided earth wire I recall and originally was fitted to the 2.0 injection on an "F" Plate (1988/1989)

[Ye Ol Ripper]

Re: Pinto Electronic Ignition

I recall that earth wire broke and it wouldn't run afterwards, can't remember exactly where it went but the control module on the sierra was over to 1 side bolted to the body.
I also on 1 occasion had to replace the ignition control module, but overall they were reliable.

With regards to the unit fitted to the distributor, I can't recall Sierras having them on the Pinto engine dizzy however they were fitted to the CVH engines and failed regularly.
I used to replace them with an intermotor part, which came with some heat sink white cement.

[philcoyle]

Re: Pinto Electronic Ignition

Fortunately I don't have to exercise the old grey matter too hard ,merely lifting the bonnet on my car gives me all the answers I want.
Firstly the braided wire, it is short and one end is crimped to the shield , the other has a terminal on it which in the case of a Bosch dizzy fits to one of the dizzy cap securing screws.
The ignition module or Ford Thick Film Ignition module was fitted on the body of the dizzy to start with until too many accidents caused it to be remotely positioned. To keep it simple Ford made the modules in grey and later design modules in black, guess what ? manufactures of the knockoff market decided to make theirs black, ALL OF THEM, confusing, of course they would fit but not perform as they were supposed to.
You have to have a good read of Ford Thick Film Ignition modules to get a grasp of the workings, it makes my brain ache, but its damn good reading.

[daveghunt]

Re: Pinto Electronic Ignition

Update on this project
Finally fitted to the vehicle, after a bit of a prayer, it started, Hooray. surprised myself?
needed a bit of adjustment for timing and time will tell how successful it's been.
Not bad for parts I've had lying around since 1999,
remember when you could wander around scrap yards picking up various parts.

Biggest problems, sorting wiring diagram, a couple of different versions around, colours didn't match.
Thanks to Steve Middletons diagram that I based mine on.
Fitting a watertight connector with no idea which pins went into which end?
Finally the bosch distributor refused to side fully into block,
after much checking diameters and lengths against the motorcraft distributor and a bit of jiggling it went home.
Nice to get there in the end with a project that's been put back on the shelf several times.

Eagle eyed amongst you will notice the control unit is held on with a clamp,
Hope it doesn't take another 20 years to get the wings off to drill the mounting holes?