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Discussion Starter #1
After much enjoyment reading a

After much enjoyment reading all the posts on the site i thought i had better join in and see if anyone can give me any pointers on my latest problem,

After some investigation into why my mondial was only firing on one bank it looks like I may have a faulty digiplex unit.

We (my auto electrical friend, and me making coffee) came to this conclusion after much fiddling with flywheel /ignition sensors and the general mess of wiring under the hood. After disconnecting both of the digiplex box’s and plugging in one at a time on either bank, seems that only one unit will generate a spark and other does nothing.

Any advice on testing and/or repairing the unit would be appreciated. Part number is MED 803 A.

Opened unit to check for any dry solder joints, no luck there yet. Nothing looks toasted in there but most of it is caked in resin.

Anyone with any feedback welcome.

I have read any and every link i could find on the digiplex and other ignition setups but have not come across and diagnostic procedure i could pass on to my auto-electrician to test.


Midlands, UK - based testing options would be great.


Regards,

Paul

thanks in advance..
 
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Discussion Starter #2
Hi Paul,

welcome to Ferrari


Hi Paul,

welcome to Ferrari-Talk.

Bad news I'm afraid on rebuilding or repairing the digiplex's. I have never heard of anyone that could remove the epoxy filler and repair the units. The best tests you have already performed, switching from one side to the other. I would think that Ferrari UK might have new units in their Vintage/Classic Parts Division and if not a used unit is the only other stock option that I'm aware of.

Although I haven't had the need to try this myself "yet", you may go with one of several programable ignition kits availible such as the Electromotive or Tech III types of ignition controllers.

HTH's

Regards, JRV
 
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Discussion Starter #4
Thanks for your input JRV,

Thanks for your input JRV,

i always hope that if i break it i can fix it. lol

i still hope it it is not the unit at fault but have yet to have it checked out. Dont know if there is equipment to test unit out of car.



Are there any good web sites for info about changing ignition systems if i have to take this option.

Regards

Paul
 
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Discussion Starter #6
Hi again Paul,

Digiplexs go


Hi again Paul,

Digiplexs going bad was fairly common when the cars were newish and used often in larger numbers than we tend to see today..


One side would start missing or lay down altogether...swap out the units, if the problem moves around with the units..walllaaa..tested.

Buying new parts for Ferraris is a fairly common occurance, and even more so as they mature. Marrelli CD Units never were all that long lasting or durable considering their price tags...just part of the game we call Ferrari ownership.

Both Electromotive & Tech III have web sites that explain how they work, etc.

Regards, JRV
 
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Discussion Starter #7
The active link didn't wor

The active link didn't work for me either, however when I C&P it did.

Takes one to the aftermarket parts upgrade section & Russ's ignition system upgrades.

We also recently discussed the need for additional ground wires and tie wrapping the harness plugs to the units.

http://www.ferrari-talk.com/discus/messages/3049/3066.html?1076660375


OK now I see the problem...the original thread by Russ may have been archived and is unasesible via direct link. See what I can do to pull it up .
 
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Discussion Starter #8
Paul,

just realized you may


Paul,

just realized you may be looking for something that never existed..a tool to test Digiplexs...the dealers to this very day still test "most" electronic units on new or old cars by plugging in a known good unit to see if the problem is thus corrected. There was no "tool or test" per se. The test always was and still is swapping the units.

Regards, JRV
 
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Discussion Starter #9
Being a dealer, it is EASY to

Being a dealer, it is EASY to test a Digiplex, etc., by using a new unit.........they have them is stock.

However, there is a tester made, by Ferrari, to test the Micropex, etc. on a testarossa, or 328, etc. It is part number 95970020, and it will test any 25-pin connector, even while the engine is running. It is a box, with a cord coming out, ending in a 25-pin connector. This connects to the ECU........the engine 25-pin connector attaches to the box. Using the holes in the box, one can check ohm and volt readings of all things that go to the ECU.......that is all sensor input, and all ECU output. Therefore, one can check all sensors to, and outputs from the ECU.

One only needs the correct values for the ohm and volt readings between the proper terminals. This is checked on the box itself (Ohm readings while the engine is off, and volt readings while the engine is running, etc.).

I can now check the sensors, and ECU output on the testarossa.....since I have those values. I recently obtained the values of the FI ECUs also, since they also are 25-pin connetions.

Hence, if one has the appropriate volt and ohm readings, this tool can test any sensor, and ECU output.........as long as it is a 25-pin connector.
 
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Discussion Starter #10
>>as long as it is a 2

>>as long as it is a 25-pin connector<<

and there lies the rub...
..the Digiplex's aren't 25 pin connectors...also the tool you refer to is for the later cars with Bosch computers...the early cars do have a plug on the left side engine compartment that a tester (timing light) plugged into. But the "tester" was far less versitale than a real timing light. If someone was just obsessed with checking a Digiplex it'e simply a matter of verifying thru the wiring diagram if every single circuit is functional...customers generally frown upon that type of use of time & their money so it's been rare and many many years ago that I took the long way around.

Henry if you don't mind how much was that tool & accesories?

Regards, JRV
 
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Discussion Starter #11
The tester was about $225.....

The tester was about $225........from a Ferrari dealer. There are no accessories.......it is just the tester and 25-pin cord.

I think it is a pretty neat tool. As you know, I am doing a service on my TR. I removed all the wiring, but will use the tester to make sure that the plugs are appropriately placed in the sensors of the engine........I know...I didn't label them properly, when I took it off..........so the sensor will come in handy. Later, I will test the sensors, while the engine is running; just as a reference.

It seems that the TR, 328, and 3.2 Mondial, all had 25-pin connectors, according to the tech manual that I have.

How many pins does the 308 have?

I can understand where this tester does take much more time..........time that a dealer doesn't want to spend. However, I think it is a nice tool for the DIYs, as I am.......where time is not money.
 
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Discussion Starter #13
During a tech session a few ye

During a tech session a few years ago, Ferrari of Seattle showed all the different types of test gear they had, laid out for all to see...sort of a hall of fame.....the tester shown was one of those....but I think they said they rarely, if ever, used it....
 
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Discussion Starter #14
Thanks for info on tester but

Thanks for info on tester but the digiplex is a 9 pin connector. I have attached some pics.





regards,

Paul
 
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Discussion Starter #15
>>328, and 3.2 Mondial

>>328, and 3.2 Mondial<<

Those 2 cars only had the 25 pin connector on the Lambda Control Computer. They both had a 16 pin Marrelli Ignition (single) system akin to the earlier daul system 308's.

Nice tool Henry. And well worth having for that price.

Regards, JRV
 
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Discussion Starter #16
Hi again all.

Well..... a


Hi again all.

Well..... after some testing, the only thing found that looked suspect was a poor solder joint on the main transistor (top left on previous top view pic). With that soldered and the box back in the car........ success, started first turn of the key.

My next move is to clean all electrical contacts and make some earthing leads ref
http://www.ferrari-talk.com/discus/messages/5/3151.html?1077573531

Many thanks for all the input and suggestions to my problem.

Regards, Paul
 
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Discussion Starter #17
Holy smoke!

A REPAIRED Digi


Holy smoke!

A REPAIRED Digiplex success story! Congrats Paul.

That's rare as hen's teeth, eh, JRV?????
 
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Discussion Starter #18
Alan - i am as stunned as you

Alan - i am as stunned as you

My mechanic did say that any other faults and it would have been a different story, but lucky for me it turned out well.

Once i got the box back from him it took me about a week to pluck up the courage to put it back in the car. lol

Paul ;-)
 
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