Re: Having some issues my with 83... (SOLVED)

toplessexpat · Post by **toplessexpat** » Wed Dec 30, 2015 9:43 am

I repeat my earlier post content - PLEASE don't ground the spark plug against "something metal" to test for spark... With any ignition, but especially the computronix. That really hot spark that's one of the big selling points can easily hurt you.

Here's some links for the right tool:

http://m.autozone.com/test-scan-and-spe ... ?location=

http://m.oreillyauto.com/mt/www.oreilly ... p?pt=N0665

RRoller123 · Post by **RRoller123** » Wed Dec 30, 2015 12:01 pm

You can also just put the timing light over each lead in succession and see if you have a blink.

76was124 · Post by **76was124** » Wed Dec 30, 2015 8:03 pm

toplessexpat wrote:I repeat my earlier post content - PLEASE don't ground the spark plug against "something metal"

I must have missed that post? Good advice, to use a tester though.

Poor choice of words on my part "hold the spark plug......"

For me, my arms are too short to hold the plug wire and crank the car from the driver's seat, so I should be safe!

bobplyler · Post by **bobplyler** » Wed Dec 30, 2015 9:03 pm

76was124 wrote: For me, my arms are too short to hold the plug wire and crank the car from the driver's seat, so I should be safe!

But, you can get your little brother to hold the plug wire while you crank. You can usually only do this once.

76was124 · Post by **76was124** » Thu Dec 31, 2015 8:02 am

bobplyler wrote:. You can usually only do this once.

Funny, but some of us are slow learners.

In my case, he got me twice as a kid with a lawn mower engine. It had the old pull start where you wrapped the cord around it and pulled. That was the 1st time holding the plug. Then he said, sorry, he'll turn it slowly by hand this time...''Pop' goes the little bro again!

However, it was a positive life changing experience for me....I learned how a magneto works, and eventually became an electrical engineer.

toplessexpat · Post by **toplessexpat** » Thu Dec 31, 2015 9:25 am

I'm laughing! Old stuff you got a little zap, and you learned to NOT do it again. Newer machinery - y'all can do yourself some damage pretty easily!

... and back to the OP - he's got a computronix... Bigger spark = more pain!

A

micbrody · Post by **micbrody** » Thu Dec 31, 2015 10:54 am

Did you get spark ? My car 1981 Fi died after running for about an hour. it would crank but never turn over. Luckily close to house . Had my son and friends push it back to garage. I eventually found inconsistent weak spark coming from coil (I had son crank ignition while i gapped the cable from coil. Very weak, not consistent spark. I changed wires. No luck. I checked coil resistance....all good. Then I read about ignition control unit. It basically shuts off low voltage side of coil causing magnetic field to collapse; and that generates high voltage discharge. No good way to check it; I did check resistance of "trigger wire" from distributor to ICM and that was normal. I then bought replacement ICM one at autozone for $22.00. (The old one was made by GM and there are many universal ones).ICM is located under coil attached to hear sink. After replacement, everything worked great.

Odoyle · Post by **Odoyle** » Thu Jan 14, 2016 1:51 am

Well, I replaced the ignition control module and the spark plug wires and she started! Success

Here's the old unit that stopped working.

New ICM unit going in.

Coil with everything back together.

rjkoop · Post by **rjkoop** » Thu Jan 14, 2016 7:12 am

Excellent. Nice to see the resolution... in case I have a similar issue in the future.

toplessexpat · Post by **toplessexpat** » Thu Jan 14, 2016 2:25 pm

It seems to be "about that time" for many of the ignition modules to fail. I've noticed an upswing in that being the issue in the last 6 months (my 81 included)

bdinardo · Post by **bdinardo** » Mon May 23, 2022 12:31 pm

Odoyle wrote:Well, I replaced the ignition control module and the spark plug wires and she started! Success

Here's the old unit that stopped working.

New ICM unit going in.

Coil with everything back together.

Odoyle,
Any chance you have the part number or information on where you purchased the replaced ICM? I'm having similar symptoms and figure I would replace mine as well. Thanks!

Disregard, Found it on Midwest Bayless. Thanks.

Brian