No spark. CDI box...coil recommendation?

[Tremelune]

Bigger spark, programmable timing, no down time, and no need to guess if the person you find to rebuild is talented.

[mysocal911]

Originally Posted by Tremelune

Bigger spark,

Where are the data? It's been discussed many times that its spark has less energy than the Bosch CDI! Besides, its second spark is too short.

Originally Posted by Tremelune

programmable timing,

The timing is proper with the Bosch. You want to have to run aviation octane fuel?

Originally Posted by Tremelune

no down time, and no need to guess if the person you find to rebuild is talented.

There are many posts about the very good quality of rebuilt Bosch units. Some rebuilders provide a 5 year warranty.
What's the warranty on your recommendation?

[gsxrken]

Bob Ashlock either direct or through PP is the right answer for CDI repairs. Very helpful with tech advice over email or on this forum, and does great work. I actually sent my working original unit into him to be updated and future proof myself from at least one known failure point on road trips.

[mysocal911]

Originally Posted by gsxrken

Bob Ashlock either direct or through PP is the right answer for CDI repairs. Very helpful with tech advice over email or on this forum, and does great work. I actually sent my working original unit into him to be updated and future proof myself from at least one known failure point on road trips.

Please describe what that "known failure point" is, which occurs "on road trips".

[mysocal911]

Here is what some "rebuilt" CDIs look like internally;

[gsxrken]

Originally Posted by mysocal911

Please describe what that "known failure point" is, which occurs "on road trips".

Not sure if you’re trolling or you’re serious but I’ll go with serious. These boxes are all aging-out, mainly the Discharge Capacitor that is buried deep in the unit under the pc-board. We are 30-40 years out on these boxes and they are failing regularly due to age, heat and use. Often on a road trip where the otherwise lightly used car is exposed to hours of running about 14” from a turbocharger and heat builds to a degree not seen otherwise. Failures usually start out as intermittent... car was running fine, shut it off and now it won’t re-start. Hours later it runs fine again. Or it won’t ever start.
If you’re still running your 40 year old one, I would seriously advise you to get it reworked in the spirit of preventative maintenance. Or ignore it and hope it doesn’t fail on you at an inopportune time.

[mysocal911]

Originally Posted by gsxrken

Not sure if you’re trolling or you’re serious but I’ll go with serious. These boxes are all aging-out, mainly the Discharge Capacitor that is buried deep in the unit under the pc-board. We are 30-40 years out on these boxes and they are failing regularly due to age, heat and use.

I've been involved with Porsche CDI units for over 30 years and that's not correct in most cases.

Originally Posted by gsxrken

Often on a road trip where the otherwise lightly used car is exposed to hours of running about 14” from a turbocharger and heat builds to a degree not seen otherwise.

Yes, turbos can be more problematic, i.e. early 911 three pin CDIs rarely fail.

Originally Posted by gsxrken

Failures usually start out as intermittent... car was running fine, shut it off and now it won’t re-start. Hours later it runs fine again. Or it won’t ever start.
If you’re still running your 40 year old one, I would seriously advise you to get it reworked in the spirit of preventative maintenance. Or ignore it and hope it doesn’t fail on you at an inopportune time.

Hopefully, your "rebuilt" is not like this one, where the "rebuilder" decides to modify the Bosch design, because of his "CDI design knowledge".



Hopefully, your warranty is at least 5 years, right?