'77 K20 just up and stopped tonight!!!

[mogulmasher]

Driving home from work tonight my '77 K20 studdered a little then just shut off and rolled to a stop. Tried restarting, no luck. Still fuel in the carb, so I'm assuming fuel pump good still.

I'm thinking the control module in the hei died, but have never had one fail. I checked the obvious, no blown coil fuse or burnt/broken/disconnected wires.

Truck has I think a msd hei distributor in it (or was a mallory??), would the aftermarket hei's have the 7-pin module or the 4???

 

[mogulmasher]

Haven't got a chance to work on truck yet, but was wondering if anyone knows if the tachometer is controlled by the control module at all? I ask cause the tach just quit about 2 weeks....wondering if it was a precursor to the truck dying.

 

[Pvt. Maggot]

On my hei the tach plugged into the cap next to where the base does, check the connection between the cap and the base, Good chance the module died.

 

[85burb4x4]

Truck has I think a msd hei distributor in it (or was a mallory??), would the aftermarket hei's have the 7-pin module or the 4???

I ran in to that problem with my bother's 84 Burb. I think they are looking up something completely different. We pulled the module and brought it with us to the parts place....if I remember right there's no 7 or 4 pin thingy to worry about.

 

[mogulmasher]

On my hei the tach plugged into the cap next to where the base does, check the connection between the cap and the base, Good chance the module died.

I think your right, I googled this question and found that the purple wire with a white stripe is the tach feed, so I guess its failure is a good indicator module died.

 

[mogulmasher]

Ended up being a broken wire! The 12v power wire was broken under the coil cap. Swapped out coil for one I had laying around the shop and its good to go!

Also discovered guy who had built this truck had the distributor 1 tooth off, so I corrected that issue and straightened out the timing. Runs like a champ now!