The Stovebolt Site Forums The Shop Area Engine Shop HEI died

I have a Langdon built S-10 HEI on the 235 in my 46 1/2 ton since 2022, the package included square coil, wires, 10 ga feed, etc
This is the first hiccup I have had with the system.
Driving home engine made a single pop and died on the spot, fortunately I just finished crossing the Richmond San Rafael Bridge and had exited the freeway in San Rafael and was 6 blocks from Hanks garage. (If it had died on that bridge I might have made the news for all the wrong reasons).
AAA came with fuel but that was no help (I trust my gauge, I could see fuel mist in the carb, but we tried fuel, why not?), so he lifted the front and dropped me off in front of my garage.
Into the garage Hank went pulled by the starter.

So, quick t-shoot said no spark, 1st thought was the D1959 module in the distributor, it is a factory ACDelco unit I had replaced to fix a stumble when I installed the distributor 2 years ago.
So off came the cap and I noticed a dirt strip inside the cap, (hmmm?).
Since I had a new ACDelco D1959 saved on the shelf… in that went… no change/ no start. So I pulled the rotor and saw more dirt under the plate atop the shaft (hmmm?). See pix…..
Set flywheel to TDC on cyl 1, Out came the distributor, in went the old point dizzy and coil, the truck started and ran fine….(just to confirm diagnosis)
In the vice went the S-10 dizzy, removed the gear off the bottom, pulled the shaft, the pickup was significantly dirty and visibly toast.
Since my S-10 distributor is a ‘non Calif” version it took a week to get the part shipped in at my local NAPA (advance tab is different for Calif version).
It arrived today, I installed it along with the (now used) 2 yr old D1959, truck fired, set the timing, and she’s running fine as ever.

For what it may or may not be worth, I don't believe Tom changed much if anything in those distributors parts-wise when they were converted. Mine did well for a while and then it didn't. Now I'm using one of the offshore copies of the coil in cap GM HEI (made either in Germany or Mexico around 1997) and it is doing just fine. Thanks for letting us know.

I’m not familiar enough with that distributor to have a theory on where the dirt might be getting in.

But that does seem weird, and it seems like a problem.

There are a couple of ways to adapt the GM reluctor and pickup coil to an original design distributor, and put the module in a remote location on an aluminum heat sink- - - -even hidden under the dash.
Jerry

For the modest price Tom charged for the unit I would/did not expect him to change out the module and pickup.
That is why I kept a spare module on the shelf, hadn’t thought about keeping an extra pickup. BTW: The vacuum advance did look brand new when it came, still does.

I will say my spark is way more stable on the timing light/flywheel than my old points distributor, and with the more powerful spark and wider plug gap the system allows, the truck runs much better.

JW51: It was from the pickup disintegrating, just looked like dirt.

Jerry, I saw you mention in a different post last week about relocating the d-1959 out of the distributor, and briefly considered what that might entail, my thought was locate near the square coil (on the inner fender) so the wires from dist to square coil would be reused, a weatherproof container/heat sink would be in order. Since I use the truck 1st order was to get back up and running, I like to work on 1 thing at a time so I limit chasing issues.
With the junk most parts store sell as wire and terminals I would look to source appropriate quality before considering. In the cab would eliminate the weather issue…

Chuck

I didn't expect it either, Chuck. Just pointing out that these parts are almost 40 years old now.

A heat sink needs airflow to work properly. It definitely doesn't need to be enclosed in a weather resistant box. I use high flexibility wire such as the type used for electronic equipment test leads for anything that might be subjected to any sort of movement, and I solder all the connections.
Jerry