'No Spark '82 SC

MAS956 · 01:13 PM

Guys,

I am in the process of buttoning everything back up in my '82 SC after an extended period (2 years) of "engine on stand" syndrome.

Everything is in place and the car cranks nicely but won't fire. No spark. I believe the problem to be something in the distributor trigger wire circuit (green wire back to wiring harness). I had to replace the wire as I broke the connector when I removed he distributor. I fished a piece of broken plastic out of the "port" the wire connects into and the new connector seems to seat well.

I spliced in a new wire and verified continuity of both the shielded and unshielded wires AND that I did not switch them when I did the splice. I think the problem must be with the distributor itself.

The Bentley manual talks of an ohm value at the leads for the trigger wire on the distributor. I assume that is a static distributor-on-bench test value. Should I be trying to read that as pulses while the engine is cranking? The meter returns no value with dizzy on the bench.

Am I missing another easy test here or does the distributor need tearing down?

Thanks,

MAS956 · 02-28-2002, 07:26 PM

Okay, I'm dying here - is there REALLY no one out there with a piece of advice for me on this issue? Shocking!

Leland Pate · 03-01-2002, 05:08 AM

I really wish I could help Mark.
I honestly have no idea... so i'll just give this a bump and see if anyone speaks up.

BenWillis · 03-01-2002, 05:40 AM

Mark,

I will give it a shot. When I put my engine back in I didnt have spark either, I noticed a red wire for the CDI box that connects seperatly from the main 6 wire plug. It is located just under the fuse panel.

If that is connected I would get a DVM and check for 12V at pin 5.

Check pin 1 for ground.

If you do in fact have a problem with the green signal wire it is most likely in the magnetic pulse generator. You might want to chech the magnet for a broken pole as well....

Hope this helps.....

Early_S_Man · 03-01-2002, 08:11 AM

Mark,

Do you have a steady 600 Ohm reading at the CDI-unit, input pins 7 and 31d, from/thru the green cable? You did not say whether you tested that static valur when you had the distributor on the bench. The 'value' of the AC signal as you spun the gear by hand would be only a few hundred milliVolts measured on the 2 Volt AC scale of a digital multimeter ... same during cranking! An oscilloscope would be much better for looking at that trigger signal.

I have the feling you have a problem with damage to the green cable or its' xconnection at the distributor magnetic pickup coil!

MAS956 · 10:35 AM

Thanks for all the suggestions. Thanks for the bump, Lee.

I'm sure that I'm getting power to the CDI as it whines with ign on.

Ben, thanks for the tip on the red wire - I don't remember seeing it.

Warren: the 600 ohm reading that you refer to is simply the resistance of the copper winding, right? (I'm an electrical troubleshooting novice extreme). I see no value at 7 and 31d and I also tried the probes directly at the trigger wire lugs on the distributor.

I guess one of those lugs might be bent or broken, so I better pull the distributor and have another look.

Thanks again for advice guys.

Early_S_Man · 03-01-2002, 10:52 AM

Mark,

If you aren't getting that reading right at the distributor ... look no further, that IS your problem!

Hopefully, there is a broken wire or terminal that can be repaired ... but if you find the problem, I suggest getting someone who is familiar, and skilled with soldering very tiny wires! The enamel insulation may have to be stripped off the wires before soldering!

A new/used distributor is your ONLY alternative!!!

MAS956 · 03-01-2002, 11:50 AM

Thanks Warren,

Looks like I've got a hot date with a bright light and a magnifying glass tonight - it's kinda hard to see exactly what's going on in there.

Mark