6-pin SC/Turbo CDI unit repair documentation

[gertk]

Just did a repair of such a module:
No ignition although the whine was there. Found out T3 was totally open.
Replaced it with a BC337 and did a dry run first, connecting an AC coupled square wave to the input and traced the signal. At the output for the thyristors gate I viewed a nice thin pulse so I decided to reassemble the box.

For testing I connected a 47 ohm 3 Watt resistor from the A connector to ground and slowly turned up the voltage on the input. The converter started its usual whine and after making sure nothing was out of the ordinary and the high DC voltage was building up I turned the voltage to 12 Volt and applied the pulse to the input. I could here the thyristor firing and after 'revving' up the dummy resistor was getting to hot to handle.. So it was outputting some power.

Next step is hooking it up to a real coil and a sparkplug and see how it handles since I do not have the car, just the box....

Any ideas why T3 has failed ?

[gertk]

Alas, according to the owner the car did not even give a single puff after reinserting the module.
So I suspect the same transistor has failed again due to some outside problem, most likely is a short behind the tachometer since that is almost directly connected to TR3

Hopefully this week the car is transported to our garage so I can have a look myself.
Shows again if you do not test and install it yourself....

[jmchrist]

a short-circuit to ground of the connection to the tachometer would not be able to kill T3. Only a short-circuit to a +12 V source could possibly do that.

[gertk]

Originally Posted by jmchrist

a short-circuit to ground of the connection to the tachometer would not be able to kill T3. Only a short-circuit to a +12 V source could possibly do that.

Yes the diode D8 should prevent a short to ground but what if the tachometer itself has poor ground then it could lift the TD pin and maybe block or damage T3
I asked the owner to see if the tach was moving during cranking and he said it was not but then again cranking rpm is quite low.
Well, hope to have the car here next Saturday..

[petro206]

Hi to all,
i'm Marco from Italy and i have a 911 2.2 T.
I try to give you some question:

In my car, the ex-owner, put a distributor (without points) and ignition from a Mercedes Benz 6 cylinder 80'S (i think mercedes W123 230)
Now, when the engine reach 4500 -5000 rpm runs bad (like the spark is no good).
I change the spark plugs and the wires, but the i had no result.

Unfortunately, i haven't the original Bosch CDI 3 pins.

Recently i bought for a few dollars this kit:

Bosch electronic ignition kit | Flickr - Photo Sharing!

link with papers

https://plus.google.com/photos/105059504495927063860/albums/5518292483816405713?authkey=CMrLk5CZxeSU1gE

1) what do you think, can i use this coil on my 911 ?
2) can i use this CDI module? (i think that the code 0 227 100 011 is for a 4 cylinders engine)
3) Can i modify this module (like to change a resistor to increase the speed of charge of the capacitor) to use in my 911?
4) Is there a D.I.Y. kit for a CDI Box or a cheap way to achieve my goal ?

thank you for your help

Ciao

[ischmitz]

The module you show is not a Bosch CDI module (capacitive discharge ignition). Bosch named these HKZ (Hochspannungs Kondensator Zuendung)


Your module is a TSZ (Transistor Spulen Zunedung) It is a transistorized igntion module (similar to what the 3.2DME uses). The module replaces the points and acts as a switch. The coil stores the energy and not a capacitor. The large resistor pack is to limit the current through the primary of the coil. The coil is different from what is used for CDI.

Not sure how easy it is to adapt this to a 911 unless you get the matching distributor and other stuff. Sounds like a project....

Ingo

[petro206]

Thank you ischmitz,
now i understand several things that before i didn't understand.
I have to reset all, and start again!

Now i find a distributor BOSCH number 0 231 159 002.
It's for a 911 2.0 S but told me that it's work on my car.

For the point 4th , do you have some ideas?

P.S.
now in my car i have installed:
Box - Bosch 0 227 100 023
Coil - Bosch 0 221 118 307
Distributor - (i didn't read the code, but mercedes pointless)

which kind of system i have? HKZ or TSZ?
Is a sh** solution?

Thank you

[HKZ Bob]

Hi Petro,

I am living in Tedesco Land and have a 3 pin cdi & coil for you.

Your English is so good, you must be a Torino GM guy or a FPT engineer.

Greetings
Bob

[petro206]

i'm a FPT engineer...

[HKZ Bob]

I might know you. I have used to work with Roberto Pittatore. Greetings to him.

[Alfasrule]

Are the transformers available for these units?
I'm working on boxes from an Alfa Montreal. There were 2 3PIN units in the car. I've changed all the components pertaining to the DC to DC converter and I still get "NO" Whining. Scoped and measured all the critical points of this circuit and they are flat. Have a "GOOD" box so I know what to see. All caps were replaced, SCR was gone so I replaced that as well. Used recommended components on this Forum. It's me last guess. What else am I missing?

[ischmitz]

What about the 2N3055 and the 82V Zener (polarity correct)? Both do fail and I asked you about the Zener polarity on the original thread.

[Alfasrule]

Believe me I got the correct zener NTE5217AK. Took some measurements tonight to see if the transformer is the culprit.
Using a Keithley 2400 Source meter I measured the 3 coils in the transformer. Forcing 100MA @2.1volts these are the reading I got:
W1 .2826ohms 28.25MV
W2 1,.94ohms 1.99.36MV
W3 .2973ohms 29.73MV
This is so cool! I've haven't done this stuff in years. Had to break out my old book from tech school, The pages are brown. It's 34 years old. Having fun learning this beast. I was lucky for a a fellow Alfisti to send me his boxes 1 BAD 1 GOOD! I looked at everything that goes on so I can only surmise that it's this component. Are these readings within normal parameters or is my diagnosis incorrect?

This WebSite is very helpful, and I'm so glad it has a spell check, cause I'm from R.I.
We's don'ts speaks English theres!

[ischmitz]

According to the data sheet the NTE5217AK has the cathode connected to the stud. The stud is screwed into the housing (GND). If you used that diode your box just draws lots of current through the forward-biased diode and the primary of the transformer.

[Alfasrule]

Different Box. The box I'm fixin' has the zener mounted on the Transiter T1. The stud must be the Cathode, because that's how it mounts in the version of the unit that I'm repairing. I know there are many versions of this unit. I have 3 in my possesion, and they are quite physically different.

[Alfasrule]

Just finished winding a tranformer for the box I'm repairing and it works great. Had to change the value of C11 to get the desired frequency. I had to reduce it to a .47uf. The box now work at the desired frequency and generates a powerful spark. I will now setup my Alfetta to test the boxes I repaired in real conditions.

[Alfasrule]

Setup my Alfetta with the Bosch Unit. Wow the car had a new LIFE. Never ran this smooth. I've repaired 3 units already. I still have to assemble 2 of them. Now I can test them under real conditions. This is COOL stuff!!

[Wolf82]

Thanks for these useful info!
Does anybody know what transformer is used in this circuit (windings,...) and/or where I can get that past?

Thanks

[Ian_Down_Under]

Question for those reading this Forum - I am in the process of repairing my Bosch 6-pin CDI (1982 Porsche 911 SC Targa) and have noted the changes suggested to date in this Forum due to obsolete / no longer manufactured components.
It appears to me that total rebuild to the original Bosch design (albeit slightly modified) would be more time/cost effective. (.
I was wondering if anyone has manufactured the original Bosch CDI printed circuit board on fiberglass (FR-4 glass epoxy). If so, how do I acquire several on these boards?

[Miduan]

I have with great interest read the post in this forum and the ones on the 3 and 8-pins Bosch CDI.
I have been given the task of repairing a 6-pin Bosch 0227 100 011 and I have not found any reference to that #number.

I have posted a few photos of the box - can anybody help with a schematic or ref. to where I can find information?

Regards Miduan