911 2.4 1973 ignition trouble

[alexnoeana]

Hello all,

I met some "problem" with my 911 2.4 T (carbs) during my last drive...

The engine suddenly stopped and I was obliged to wait assistance for 2 hours...

After a quick inspection there's no spark comming from the coil...

I've checked the coil with an Ohmmeter and values are right.

BKZ box seems to be OK and make his usual sound...

Ignition leads are new (2 years old) as spark plugs...

On my opinion trouble comes from the distributor (original Bosch never dismantle with 120 000 km)...

I need your help to check it. Do you know an easy method???

Does the distributor inclose a condenser or a coil???

Thank you in advance for your help

[kent olsen]

Check the rotor. I've had one fail at an autox. I think I used one from a VW to get home and then replaced it all with Pertronix.

[LakeCleElum]

Like Kent, I had a rotor go bad stranding me 100 miles from home....I cut an unused wire under the dash, JB Weld on both ends and limped home......

[HarryD]

Lots of threads on this topic. Here’s one:
How do i check a coil with a timing light??

To get a spark to the spark plug in the engine. Several things need to happen. First, you need power to the CDI. Next you need to have a way to trigger the CDI (the points do this by opening and closing). Then the CDI will then send a pulse to the coil which will increause the voltage and send it through the high tension lead to the rotor and to the selected spark plug. You need to verify that each step in this chain is working.

1) Verify that the CDI is getting power. Do you hear it wining (if it is a Bosch unit)? If so, you should be good to go.

2) Verify that the CDI is producing power to make a spark. You can do this with a "telegraph" test. Take the high tension lead off of the center of the distributor and put a spark plug on it. Ground the threaded part. With your plug attached to the center lead, open the distributor, remove the rotor, place your key in the run position, and manually open and close the points. Each time you cycle, you should see a spark from the plug. If you do not, you may have a bad CDI.

3) Verify that the coil gets a signal when you crank. Replace the rotor and distributor cap. Leave the plug on the center high tension lead. Crank the engine. Do you see a spark? If so, you are getting spark to the distributor. If not, your point gap may be off or there is some other problem with the connections.

4) Verify that the spark goes to the spark plug wires. Reattach the center lead to the distributor. Attach you spark plug to one of the leads going to the cylinder spark plugs and ground. Crank engine. If you see a spark you may have a timing problem. If no spark, you have a problem with your rotor or distributor cap or your wires are improperly seated.

Do a search here as there are many threads on this topic. Look especially for the ones by early_s_man. Warren (RIP) left a great deal of knowledge on troubleshooting this problem.

[alexnoeana]

Thank you all for your help!

I have 3 questions:

1) Does the distributor include a condensator coil?
2) could you confirm me the CDI ignition Bosch box reference: 0227200001
3) Could you confirme me the distributor reference: JFUD6

Thank you again...

[T77911S]

no condenser for your ignition.
your points only provide a ground.
make sure the gap is set, the gap is not critical but the points do need to open and close.
a lot of the time the plastic part that rubs on the dist shaft wears down and the points don't open enough to break the ground.

[faapgar]

A lot of times you just take a dry matchbook and wipe it between the points in the dizzy.You will see a slight film of oil stain.Sometimes do it twice.Common on 69-77 911 with points.Ciao Fred

[alexnoeana]

Thank you again for your help

Could anyone just confim me distributor and CDI serial numbers ?

[fizeus]

Originally Posted by alexnoeana

Thank you again for your help

Could anyone just confim me distributor and CDI serial numbers ?

Alex,

CDI box should be OK for your car.
(In my knowledge any running CDI box 3-PIN model fits well on your car ... but probably more experienced user can chime in)

Not the same story for the distributor: it needs to have the correct advancing curve for the engine to run ok (or without detonation) .

You posted just a part of the distributor model, infact JFUD6 simply identify a series of bosch distributors.

You have to post the distributor part number.

Your distributor part number should be 0231169008

Many other distributors can be right for your engine because all the distributors for the 1973 engines share the same advancing curve ... the only difference in distributors for T,E,S models is the rev limiter on the rotor.

Hope this helps

[fizeus]

Looking at my reference books correct distributors for your engine are in the 0-231-169 range

0231-169-003
0231-169-004
0231-169-005
0231-169-008
0231-169-009
0231-169-010

P.S. A sudden engine stop should point you toward a CDI problem more than a distributor problem.
I think HarryD gave you a lot of precious suggestions but please note that a whining CDI do not mean it's working (ask me how i know).

[E Sully]

The CDI box may be an issue even if you hear the high pitched whine. The number you listed is correct for the CDI.
The distributor number above the JFUD6 would originally have been 0 231 169 00X, although the later '74 on 0 231 184 00X can be used, except the 184 004 which had a different curve for the Carreras. If you need a replacement distributor and are not worried about numbers matching, the 184 00x are an improved design. The 0231 169 008 was specific to the 1973.5 CIS, but advance curves are similar to earlier numbers, rev limiting rotors being main difference.
This site can give you some information on distributors. Early 911 Distributors - Carbs-Fuel-Ignition (CFI) - Repair & Sales

[alexnoeana]

As I m living in France, I'm asking some questions...

In US you use "CDI" for the BOX

In Germany they use "HKZ" ...

Is there a difference or is it the same box????

Thank you for your help

[fizeus]

No. They are the sinonyms.
Capacitor discharge ignition systems (CDI) and hkz are the same device with different name

[alexnoeana]

Hello all,

Good news!!!! I've restarted my engine...

I've taken some holidays and finally found success at 20:00 on december 31st....

I spent a lot of time following all your advices...

Finally the problem came from the coil (Bosch) and... the points!!!!

In fact coils values were right on the multimeter .... so I was sure coils was good... wrong way.

My new coil is a "BERU" ... Have you good experience with this brand?

Thank you all for your help and happy new year ... with your 911 of course!!!

[fizeus]

Originally Posted by alexnoeana

Hello all,
My new coil is a "BERU" ... Have you good experience with this brand?

Glad to read you had success with your 911, I imagine you had a very happy new year

I know BERU is ok for replacement of the bosch coil, even if, some pelicans had spurious problems.
To be sure take the car for a ride and test engine response at high RPMs


As suggested you can buy a FlameThrower (our host) or a coil form parts_klassik_._com just as spare unit.