Stranded on the side of the hiway tonight

[P10crew]

First time I've been dead sol on the side of the road in my personal vehicle in 40 years.
Even though I drive a lot of old stuff I usually keep them fresh enough that I don't have problems at 50 mph truck just shut off no warnings at all.
2 questions for the pros since I'm about 90% sure it's an ignition module.
Cap and rotor are new ac delco with 20 miles on them. Module is 2 years old don't remember where I got it.
1. Were these coils known for failure?
2. Is the delco my best bet for a new module?

On other gen 2's that I have ran I have had one of the little wires inside the distributor from the pick up to the module break but that happened in the driveway one cold winters morning.
Thank god for my neighbor who rushed right down and towed me 2 miles home.

1990 GM 350

 

[JHZR2]

Seems kind of strange that they only have 20 miles on them...

Can you check that everything is screwed on and together? I assume they take a Tory bit?

 

[spasm3]

https://www.jalopyjournal.com/forum/threads/is-there-a-way-to-test-an-hei-module.706237/

 

[P10crew]

I just replaced intake gaskets on this truck. While I had it apart I put new ac delco cap and rotor on it . Everything is or was tight and in place.
I rechecked all of the wiring harness connectors tonight all is good.

 

[mk378]

Of course you should do a little troubleshooting like a spark test from the coil wire and test for 12 volts on the input wires to the coil.

If it has power but doesn't spark at all, those 4+2 wire modules (+2 wires for the sensor inside) are all lemons no matter what brand. Carry a spare.

I had a car blow two or three of those module by going wide open up an on ramp then lifting off the gas suddenly. Learned not to do that.

 

[P10crew]

The only thing I checked before I came in the house for the night was that I verified no spark at the coil. Nothing else was tested.

 

[clinebarger]

The idea with the test light is to make & break contact quickly in repetition on steps #4 & #6.......

1. Using a Incandescent "Bulb" type test light connected to B+.

2. Disconnect the 4-terminal connector at the ICM.

3. Turn the key on.

4. Touch the test light to the Purple/White wire and check for an injector pulse.

5. If injector pulse is generated, reconnect the ICM and remove the distributor cap.

6. With test light still connected to B+ touch it to the Green wire of the pickup coil attached to the ignition control module at the terminal labeled "P" with the key on.

7. Check for injector pulse and spark.

8. If no spark is generated during step #6, Verify the ignition coil has good power supply. Connect a Second test light across the White wire (coil trigger) and the Pink wire (coil power) at the coil and repeat step #6. If the test light blinks, replace the coil.

 

[P10crew]

I'll check it out tomorrow. Thanks
Is delco the best source for these components or standard?

 

[clinebarger]

The original "Paint Dot"/"White Letter" IC modules were pretty good.....They haven't been in production for several years. Even the supposed OE ICM's produced today aren't that durable.

 

[P10crew]

CLine on the last gen 2 that I had one of the pickup wires broke which means that the shaft must be pressed out to replace the pick up. The shafts have varnish build up inside the shaft tube. When you press the shaft out it wipes out the upper bushing even after soaking the bushings and shaft with acetone and atf. The rebuilt ac delco rebuilt complete distributors are junk some have used modules and pick ups.
Not real sure what to do if the pick up is bad or broken wire.

 

[clinebarger]

Technically....Your engine is a Gen 1 SBC, Gen 2 was the LT1 & L99 with the infamous Optispark.

I'm well aware of varnished shafts wiping out the bushing, Or just the bushing already being worn!

I use a GMPP RamJet distributor GM# 1104060.....You just have to swap the drive gear as it's "Melonized" for steel roller cams, It may work on a cast iron cam, But I'm not brave enough to find out!!! https://www.summitracing.com/parts/ado-1104060?rrec=true

I believe your talking about the 19179575 AC-Delco reman which is over $100 more & has a core charge? https://www.summitracing.com/parts/ado-19179575/applications/make/chevrolet/engine-size/5-7l-350

 

[clinebarger]

You may get lucky & receive a NOS RamJet distributor with a "Paint Dot" ICM, This distributor doesn't cross reference to any OE application so they don't get sold very often!

 

[oldhp]

It's been a long time but I think when spinning engine over you should read 6 volts AC output from the pick-up coil if good.
Those GM ignition coils are pretty good. A lot of modified dirt cars use them. Pretty much bullet proof according to them. Good Luck!!!!

 

[P10crew]

Thanks fellas.
Another broken pick up wire on this one.
Thanks for the info on the gmpp dist. I saw that last night on summit and yes the delco rebuilt units are crazy high $.
Best spent money will be on the new gmpp . Thanks
When I swap gears I just clock it the same as the old one correct?

Thinking now about selling this old girl and finding a super clean early ls truck....... lol

 

[P10crew]

Got lucky there. According to summit tech team gm has discontinued this and summit only has 20 units. All of which are in the Arlington TX warehouse. 19 now

 

[Yah-Tah-Hey]

Murphy is alive and well P10.

 

[clinebarger]

Originally Posted by P10crew
Got lucky there. According to summit tech team gm has discontinued this and summit only has 20 units. All of which are in the Arlington TX warehouse. 19 now

I love that place, It's exactly 22 miles from my house.

No need to index the gear.

 

[P10crew]

Well I ordered it one week ago tomorrow second day air.
Had to go to the fedx terminal to pick it up today.... delayed because of blizzard last weekend.
The module has the paint dot but no white lettering.
I'll post pics tomorrow.

 

[P10crew]

 

[clinebarger]

Unfortunately that's not a NOS module......

This is a 7-pin for a large cap HEI, But your style would look very similar on the markings (Paint dot, White letters, & Raised GM logo)