No Spark.

[TorqueWinsRaces]

1979 Jeep Wagoneer, 360 V8. I have the official shop manual.

I'm getting no spark. The coil resistance was 7.2 kohms, so I replaced it. Still no spark. Distributor or ECU probably? I tested the output of the distributor and I think I did it right because my meter (Fluke 83) was fluctuating, but that just tests the Hall effect sensor, right? I did a couple of the tests for the ECU (don't remember which ones right off the top of my head) and they all passed. I have 12vdc @ the pos. terminal of the coil.

Help? Let me know any additional info you may need.

Oh, it seems to have started as an intermittent thing. It would die immediately after starting for the first time of the day, then it wouldn't start again for an hour, or so. I thought I was flooding it somehow... As soon as it started and got going for a few seconds it would stay lit and run like a champ, restart with no problems once warm, etc. Then, a few days ago it just wouldn't start. I have one of those inline spark testers, so I threw it on and found that there was no spark. So, here we are...

 

[54cj3b]

check wire from dist to coil and were ever else they run for a short or broken wire

 

[SteelHeadz]

Check the resistor wire from the coil to the junction block on the firewall. Make sure its not intermittent open.

 

[JEEPNXJ96]

don't those have that ignition module on the fenderwell??? I was working on a cj5 w/360, and that was the problem

 

[TorqueWinsRaces]

All wires test good. I ordered a used ign. module for $35. I should have it in a day or two.

 

[TorqueWinsRaces]

Tried the key for grins and it started right up. I hate intermittent problems. Hopefully the problem is in the ignition module and the new one will fix it.

 

[carnuck]

Could be the ignition slider switch is worn out too.

 

[osnixpero]

had the exact same thing on my 86 grand waggy. check the wires from the distributor backwards. i found many cracks on all those wires. when i put new wire in the bad wires place the problem went away. p.s. i love your german sheapard!

 

[TorqueWinsRaces]

Thanks for the input.

As I mentioned, I tried to start it and it fired right up. Installed the "new" ign module and it was deader than a doornail. So, that didn't solve anything. The junk yard is sending me a replacement module. With that said, my module could still be the problem. After it started, I went ahead and changed the plug wires and buttoned everything back up, and...nothing. Dead again. So, the replacement module should be here Monday.

I have checked all of the wires using an ohm meter. As you know, if the ign is not firing, the open wire (if that's the problem) will present itself. With the ign still not firing, every wire tests good. It's got to either be the distributor or the ign module, right?

What is an ignition slider switch? Edit- I wonder if my brother's old Ford farm truck has one of those? You have to start the truck using a screwdriver on what I would describe as a slider switch. Does my jeep have one of those? It has a GM tilt column.

I love my German Shepherd too!!! His name is Jake and he is a fantastic friend and bodyguard.

Edit- One other thing. I know I mentioned this in my original post, but I wanted to reiterate. When it dies it does the exact same thing every time. It fires for just about 2 seconds immediately after turning the key- then dies and all spark is gone. It never, ever happens when the vehicle is warm, only on the first start of the day.

 

[SteelHeadz]

Yes, you have it on that GM steering column. The ignition switch(slider) is located on the lower top end of the column right above the brake pedal. There is a minute adjustment slots on the switch mounting holes to properly get it at the right position.

 

[54cj3b]

check wire from dist to coil and were ever else they run for a short or broken wire

Like I said in the first post trace the wires by hand from dist to coil and where ever else they go bet you any amount of money theres a frayed wire grounding out like I said the first time meters sometime lie trust me been there done that dont just look and say ok nothing realy look inspect every spec of each wire with your eyes and hands then when you find it you can:givemebeer:

 

[TorqueWinsRaces]

Like I said in the first post trace the wires by hand from dist to coil and where ever else they go bet you any amount of money theres a frayed wire grounding out like I said the first time meters sometime lie trust me been there done that dont just look and say ok nothing realy look inspect every spec of each wire with your eyes and hands then when you find it you can:givemebeer:

My engine compartment is pretty clean and my wires are all routed neatly and in good shape. I'm actually an electronic technician and I have about 30 years of experience working on cars- just pointing out that I'm not a n00b. I seriously appreciate the input, but the problem is not a frayed wire. It could, however, be an open wire in the distributor circuit.

Regarding that slider switch- Does the ignition signal run through that switch, or just the start signal? It turns over fine, it just has no spark...I suppose I could look at the schematic, but it's out in the Jeep.

Going back to the wires...I have looked and looked and looked; I can find no problems. I have moved the wires while trying to start it. I have a $300 Fluke DMM that used to ohm out the wires, even the resistor wire checks correctly.

When I get motivated, I'll go get the schematic and check that slider switch signal.

One other thing- This Jeep uses the MotorCraft ignition module. While a big leap in technology, it was a piece of junk. I've had a couple of vehicles that use the blue-tag box and I have yet to own one that I didn't have to replace- multiple times. This one has already been replaced at least once because the one on the Jeep now is not the original.

 

[TorqueWinsRaces]

I got my new module today. Starts with the new one, doesn't start with the old one. I'm gonna call it fixed. Thanks for the help!