No Spark 86 C10

[Newfie98]

Hi, I am having a little trouble trying to get my 86 C10 up and running. I just completed an engine swap to a 355 SBC and actually had the truck up and running enough to make a few trips around the block. Went to start it the other day and no dice. I pulled the plugs and have no spark.

I installed a brand new MSD Streetfire distributor when installing the motor and made sure to set the timing with a timing light. I cannot understand why I have no spark now all of a sudden. I checked to ensure that I had 12 volts on the battery side of the distributor with the key in the on position and I do, so if power is getting to the distributor the problem must be with the distributor right? I tried dropping in another distributor (factory GM unit that I was told was good) and that made no difference. I am really stumped at what else to check, I know some people are saying esc but that shouldn't matter with the MSD setup right?

If anyone has any suggestions on what to try next I would appreciate it very much, Thanks!

 

[Squirrely Brother]

Out of curiosity did you turn your crank to tdc on the compression stroke for #1 cylinder? If you spiked the new distributor with the rotor in the same spot as prior it would be an act of God for you to have been at tdc. I found this out years ago on a C3 Corvette. I didn’t know better at the time and spent 2 days and finally with guidance from a man at NAPA got it to fire. Pre-internet could be rough at times.

 

[Newfie98]

Yes, I marked the location of the MSD distributor before removing it but I also ensured the engine was at TDC on cylinder #1 by removing the valve cover, spark plug, and lining up the mark on the balancer with the timing tab so should be no issues with timing (should be at least close enough to spark). I have power going to the distributor and the rotor is spinning so I am puzzled as to why I still have no spark. I could understand one distributor going bad (even though it is a brand new unit) but even after changing distributors and re-timing I still have no spark. Like I said it was running good previously.

 

[Bextreme04]

Yes, I marked the location of the MSD distributor before removing it but I also ensured the engine was at TDC on cylinder #1 by removing the valve cover, spark plug, and lining up the mark on the balancer with the timing tab so should be no issues with timing (should be at least close enough to spark). I have power going to the distributor and the rotor is spinning so I am puzzled as to why I still have no spark. I could understand one distributor going bad (even though it is a brand new unit) but even after changing distributors and re-timing I still have no spark. Like I said it was running good previously.

Did you check that you have power to the distributor?

If you have power to the distributor, but no spark, then you either have a bad ignition module or a bad coil.

 

[Newfie98]

Yeah I have 12 Volts at the distributor, even tried running it with a jumper wire straight from positive on the battery to the battery terminal on the distributor and that didn't make a difference. I have tried installing a different distributor and re-timing the motor and that distributor will not give any spark either. If I take the cap off I can see the rotor spinning so I would assume it's meshed with the cam
gear properly.

 

[John Nes]

So you marked the caps location, but did ya ‘member to point the rotor directly at #1 when goin back to TDC? Got the right balancer on there? No spark or a super weak spark? Sure your wires are in the right firing order? Double checked your wiring? Seen this a lot where customers did their own distributor job, and then towed it in cuz it didn’t run or ran like crap.
If you hold the pedal to the floor while spinning it, does it fire?

 

[Newfie98]

I figured it out after, the plugin coming out of the harness that connects to the Battery terminal on the distributor was shorted inside the plugin itself. It still read 12V when checked with a meter but wasn't making good contact with the distributor terminal.

 

[Grit dog]

^ dang frustrating chasing down random electrical shorts… nice work!
How she run now?