ignition coil testing- not in Bentleys- anyone?
 

Hi-me again,
Bentleys has no 'table B' values as supposed to be on page 280-9 in Bentleys Carrera version- maybe similar to Bentleys SC coil values?.
I got 6,800 ohms from positive to centre and only 6 ohms positive to negative!
Are these value about right?
It was a new coil!.
rgds Ben

Ben--here's what the Haynes manual says:
Remove the ignition coil connections and connect an ohmmeter between the coil terminals 1 and 15 (primary); there should be a resistance of 0.4 to 0.6 ohms. Repeat the check between terminals 1 and 4; there should be a resistance of 650 to 790ohms. Your numbers are right on IF you are reading the times ten scale!
Haynes also says if you can't hear the CD unit whistling, the CD unit is defective. They suggest you remove the center wire from the distributor and place it about 3/8" from an engine ground where it will stay without you holding it (it'll knock you on your keester!) and have someone try starting. Watch to see if you're getting a nice fat regular spark. Hang in there!

George 86T

I also tested my coil last night, since we were thinking it could be the wrong one. I got 3.4 ohms from the primary and 20500 or was it 10500..well too much anyway. So I guess I will have to change the coil.

Before you test the CD unit that way, make damn sure that there is no fuel leaks. Would be a very bad thing...

Randy

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Friends don't let friends drive RICE!

1978 911 SC

Guys ...

Ben has an '86 with 3.2 Motronic, not an earlier CDI-system! The coils are NOT THE SAME!!!

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Warren Hall
1973 911S Targa

Thanks George,
I did use to have a Haynes but it got lost somewhere since i got the Bentleys http://www.pelicanparts.com/ultimate/rolleyes.gif
I WAS getting 6.8K ohms!. I will re check it today!.
This was with a new coil?
rgds Ben

Ben,

The specs Jorgeman cited from the Haynes manual are NOT for your coil! They are for a CDI-system coil used in SCs and earlier cars, as well as Turbos.

How did your old coil's test values compare with the new one?

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Warren Hall
1973 911S Targa

Sorry Ben--Warren is right! I assumed yours was a CD system and you know the old saying about assuming. I'll see what I can find on the later coils and get back to you.

George 86T