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1969 Blazer | Backfires | Won't start

fear_nothing

fear_nothing

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Looking for some ideas. My '69 Blazer with a 350 lost spark this fall. Traced it back to a broken rotor—a chunk of plastic broke off and damaged the metal portion of the rotor. I replaced the rotor and ignition module and went ahead and swapped the coil, too (though the root cause was probably just the rotor). Got the spark back, but now it won’t start.

It’accell.jpg
 
What did the cap look like inside? If the rotor brokeI wouldn't be surprised if cap has damage
 
A few ideas:
  1. Any new parts could be bad (i.e. module and coil), so swapping the old ones back might give some information. (Especially because it's Accel.)
  2. It's possible the distributor was never installed correctly. The wires may have been off by 1 position before you started. It may help to put it at #1 TDC and verify where the rotor is pointing.
  3. Have you verified that the sharpie #'s on the wires are actually connected to those plugs?
  4. You can verify with a timing light that there is actually spark in the wires. It's possible one of the spade connectors to the coil, module, etc didn't line up right on install. If it's not sparking, it doesn't really matter where the wires are routed.
 
Blue85 said:
A few ideas:
  1. Any new parts could be bad (i.e. module and coil), so swapping the old ones back might give some information. (Especially because it's Accel.)
  2. It's possible the distributor was never installed correctly. The wires may have been off by 1 position before you started. It may help to put it at #1 TDC and verify where the rotor is pointing.
  3. Have you verified that the sharpie #'s on the wires are actually connected to those plugs?
  4. You can verify with a timing light that there is actually spark in the wires. It's possible one of the spade connectors to the coil, module, etc didn't line up right on install. If it's not sparking, it doesn't really matter where the wires are routed.
Click to expand...
  1. Initial Troubleshooting: I had the same thought — ordered and tested two new coils before even pulling the distributor cap. No signs of life (not even a backfire) until the rotor was replaced.
  2. Verification Steps: Good call — TDC was confirmed during the process.
  3. Firing Order Issue: The firing order marked on the distributor (courtesy of a sharpie) turned out to be incorrect. That’s how the wires were set up before I began troubleshooting.
  4. Next Steps: Haven’t tried this approach yet, but it's on the list.

The wildest part? If I close my eyes and randomly plug the wires in, it almost starts with more promise than when the correct firing order is followed
:doah:
 
fear_nothing said:
  1. Verification Steps: Good call — TDC was confirmed during the process.
Click to expand...
If that's the case, then you can put the timing light on #1 and it will flash the base timing on the tab - for confirmation. This is easy with a remote starter solenoid, but there are other solutions, like a helper. Keep in mind #1 TDC comes twice in every revolution. Apparently, an engine will run ever so little with the distributor 180 degrees out. Any chance the plug wires were 180 off when your started?

Is it backfiring or not firing at all? Are you sure there's gas in the bowl?
 
If the dist us stabbed correct clocking,the first pick is very advanced base timing.
 
Blue85 said:
Is it backfiring or not firing at all? Are you sure there's gas in the bowl?
Click to expand...
I’m betting the timing is 180 degrees out — it runs briefly during troubleshooting sessions but sounds terrible.

There’s fuel in the filter, fuel in the bowl, and I even added a bit more just to be sure.

About half of the plug wires were routed incorrectly, and it's currently backfiring pretty severely.
 
fear_nothing said:
I’m betting the timing is 180 degrees out — it runs briefly during troubleshooting sessions but sounds terrible.

There’s fuel in the filter, fuel in the bowl, and I even added a bit more just to be sure.

About half of the plug wires were routed incorrectly, and it's currently backfiring pretty severely.
Click to expand...
The backfire is the sign, you're 180 out
 
My first Chevy II after inspection deal was struck, $400. I went out put the rotor on correctly and drove off.
64 Red 2 door coupe, 283 4jet power gylde. Owner had some work done new valve job and it never ran agian. That 283 was tried. After a couple years I called it my Mosquito abatement machine, anyone remember Raylube ?
 
Wes Harden said:
My first Chevy II after inspection deal was struck, $400. I went out put the rotor on correctly and drove off.
64 Red 2 door coupe, 283 4jet power gylde. Owner had some work done new valve job and it never ran agian. That 283 was tried. After a couple years I called it my Mosquito abatement machine, anyone remember Raylube ?
Click to expand...
That was my smokey Joe, the turbo diesel 76 k5.
 
Well the battery is good...

You should probably stop cranking it with that backfire, for risk of a fire. Speaking of which, those clear fuel filters are not recommended and upgrading the transmission dipstick to the locking type is. I would go back to the beginning, get #1 on TDC (compression) and see where the rotor is pointing. If you're in a hurry and really suspect being 180 out, you could move all the plug wires by 180 to see if that mostly fixes it.

A timing light will tell you that 180 out is right.
 
My distributor was one tooth off when I had the same issue last spring after changing the flywheel.
 
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