[TR] Testing ignition coil: what am I doing wrong????

[spamiam at comcast.net]

Dave

>btw - coils rarely go bad.

I agree.  Testing the coil is actually part of a bigger testing process. 
The problem I am trying to solve is the lack of a spark on my TR7.  It has a 
Delco distributor with the oddball Delco HEI ignition system.  The car has 
been acting as if it has a weak spark, and I tested the spark with the spark 
gap tester.  I got no spark.  So I tested the HEI system and found it had 
good power and good ground.  I have no good way to test the reluctor in the 
distributor (not that I know of, anyway), so I replaced the 4-pin ignition 
module with a new spare.  Still no spark.

So, I figured it could be the HEI coil or the reluctor.  To prove which, I 
wanted to swap the HEI coil with a regular 12V coil, but the HEI coil is 
mounted with very short leads to the Delco electronic ignition unit.

So, I decided to hook up the old HEI ignition module to a normal 12 volt 
coil separately.  The module got mounted on a big heatsink, and the B 
terminal got +12v and also went to the (+) terminal of the 12V coil.  The C 
terminal went to the (-) terminal of the coil.  I hooked up the 
distributor's wire to the appropriate W & G terminals on the module.  When 
cranking the engine I got no spark from the 12V test coil either!

So I decided to see if I could get ANY spark from the test coil, hence my 
question posted earlier in which I found no spark that way either! I will 
check youtube for test procedures.

-Tony

-----Original Message----- 
From: Dave
Sent: Sunday, June 17, 2012 9:18 AM
To: spamiam at comcast.net
Subject: Re: [TR] Testing ignition coil: what am I doing wrong????

go to youtube, and search test ignition coil.  moss motors has a very good
one; I bet john twist of university motors also has one; and I am sure there
are others.

you can also test with an ohmmeter; it should read either 1.5 or 3.0 ohms.

the coil is not grounded per se.  you have to use the leads.

btw - coils rarely go bad.