Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)
-   -   No spark / question on wiring (http://forums.pelicanparts.com/porsche-911-technical-forum/829015-no-spark-question-wiring.html)

BartdeBruijn 09-08-2014 11:24 PM

No spark / question on wiring
 
Hi!

Car: Porsche 911 2.0T 1969 with CDI-unit original car/wiring as far I know…

Car almost completed after 18 year full nut and bolt restoration.
This is the last step before first start up after all these years however For starting I need a spark ;-)

So this is what I did/checked

After connecting wires as shown in diagram the following can be observed when contact in on (step before starting) :
CDI-unit is making high frequency noise.
There is voltage on the lead that goes to the distributor
There is voltage at the arm of the contact points when gap is open
There is no voltage at the arm when gap is closed
There is no voltage at the ignition coil input side (not when gap is open or closed…..?
SEE ATTACHED PICTURE OFF CURRENT WIRING DIAGRAM

What is wrong here?
Could it be wiring?
Any suggestions
In the drawing the part in the red circle…. What component is this? Should it be in or are the wires wrong connected here?
The other wiring I am quit confident…..

Thanks already!

Cheers,
Bart



http://forums.pelicanparts.com/uploa...1410247284.jpg

T77911S 09-09-2014 02:40 AM

that may be a speed switch.

your tach is wired wrong. unless it is different for 69, the tach is wired to the points, you have it the HV (450v) from the CD unit. i hope you did not hurt the tach.

oh, that speed switch is also wired off the points. there should only be one wire going to the coil, that is the HV wire from the CD unit.
i assume that speed switch is just a rev limiter. that may be history too.

BartdeBruijn 09-09-2014 03:18 AM

pinning CDI-box
 
Hi

Stupid me, ay?
car electronics is not my strong point ;-)

So to be clear....

- I got a voltage over my breaker points which is wrong ok?!
- High voltage (450V) should be the blue CDI wire going to the coil positive lead?
- breaker points should not get any voltage but only opening and closing earth / mass connection
- Tach should be connected to distributor.

Any idea about pinning of CDI box?
If you look at it as mounted (ribs facing towards me) blue - red - black is that right?

Thanks!

T77911S 09-09-2014 05:39 AM

blue line to coil only.

tach and speed thingy go to points. actually there may be a connection for them near the CD unit.

points are just a switched ground.

BartdeBruijn 09-09-2014 08:19 AM

Yeah, that's clear to me however I measure a voltage at the black wire coming from the CDI.....
It reads 12V....
Guess my CDI box is fried.....however it does makes the famous wining sound.

Any idea?
Thanks

ischmitz 09-09-2014 08:38 AM

Terminal A at the CDI box will measure +12V (consider it an output of the CDI box). There is an internal resistor (either 33 Ohm or 100 Ohm to terminal B, +12V). When you ground Terminal A (points close) the box releases a spark. Try that first. If that doesn't work your box needs repair.

For good measure I would remove both the speed switch and tachometer so they don't interfere. They both could have been damaged by hooking them up to the HV output.

Regards,
Ingo

T77911S 09-09-2014 09:58 AM

what ingo said.
go ahead and connect it back up, without tach and speed sw. and give it a try


All times are GMT -8. The time now is 06:25 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.