dkcaims

90 C4
Stock black Bosch coils (made in spain)

1st Coil = Primary .001 (gauge set to 2k) and .9 (gauge set to 200)
Secondary 6.18 (gauge set to 20k)

2nd Coil = Primary .001 (gauge set to 2k) and .9 (gauge set to 200)
Secondary 6.08 (gauge set to 20k)

Just not quite sure the settings on the meter measuring across the primaries are correct.
Here are a few pics...
Thanks in advance for your help
Derek

Lorenfb

Read here under "Typical Ignition Coil Values":

http://www.systemsc.com/diagnostic.htm

ToreB

Measuring high voltage coils with a ohmmeter will probably not produce reliable results. You will be able to discover basic short circuits and maybe differences in the readings between the two. But, you'll have to use a megger or other coil testing equipment to really determine any faults. These instruments are made to discover faults in the insulation in the high voltage winding.
Cheers,
Tore

dkcaims

Thanks Loren...
I sent you an email

Thank you also Tore !

newsboy

Do you have an electrical problem, or just testing? I had values of 0.0 primary and 5.2 and 5.4 secondary, which are within the accepted range. Was dealing with "Christmas Tree". I have been told that even if the coils test O.K., they can have internal faults. I changed them, and it cured my problem.

milutintin

According to the workshop manual:

Primary resistor: Terminal 1-15 = 0.4 - 0.6 Ohms
Secondary resistor: Terminal 1-4 = 5 - 7.2 kOhms

I changed mine in order to solve Xmas tree. Mine were in the lower range of the secondary resistor. New ones were in the upper range.

Geoffrey

I agree with Lauren here, we just had an issue where the coil bench tested fine with an ohm meter but when put on a test stand would not fire. This was on a 993 and was the source of an issue on a new engine.

dkcaims

Car runs fine, starts fine... but rich all of a sudden. 10.5 AFR at idle and low load.
AFR's were perfect the day before.
Looking into ground issues and cht sensor today.
Coils are back in the car for now.

dkcaims

Problem detailed in this thread... I just decided to check the coils while they were out while I was cleaning up the ground point behind the coils.
https://rennlist.com/forums/964-foru...ning-rich.html

Dashing Chris

Recently I am getting wired noises and give me starting problem, discusses with my friend he suggested checking VW, not knowing what it is, he suggested giving Testing VW with a Multimeter a read...