No Spark

[Canon Lansdell]

I'm pretty sure spark is generated based on CPS output, but I'd still say good idea to check the connection.

I can't imagine why you would have spark on the coil wire but no spark coming out of the distributor. That would point to the cap, no? The contacts seem okay?

Does the spark seem strong? Can it jump a good distance? I want to say, should be able to jump across like 3/8" to 1/2" gap?

The spark looked like it jumped that far and looked good. As far as the contacts being bad, how would i be able to identify that? would they look burnt? cap was fine before i removed it.

 

[Canon Lansdell]

There's a whole procedure to align the distributor angle, via a scanner for all Vortec L30 and L31 engines. What degree is the distributor offset on your scanner?

i don’t have a scanner but i marked the position of the distributor and realigned it properly with how it was before.

 

[Canon Lansdell]

If you removed parts and did not break anything, made needed repairs, then installed all parts, connections, with no " oh ****" , using correct procedures. Then something was missed or you have had some type of sudden catastrophic failure. You have a strong spark on coil output dist' side wire? Swap out cap and or rotor. For fast check or inspect both closely. If coil is alive whats keeping energy from cap to rotor to plug wire to ground through plug? Cracked cap ( oops dropped it) crap rotor spring thing, corrosion in cap or coil wire wells. Thats what i would do. Good luck.

The cap is still in good shape, but i did notice a little bit of wear on the rotor. right in the middle, it appears there is a tad “burn”, but from what i’ve seen that’s normal. once again, still lost on why it would happen when everything was fine before

 

[east302]

Any distributor tabs broken?

I’d agree that it points to the cap if the coil wire sparks but the plug wires don’t.

It should still turn over with the CMP offset being out within reason - and I’d put money on it being out by a few degrees until you can get a scanner on it to set it. Since it’s a free check, loosen the hold down clamp and twist the head of the distributor until the distributor cap mounting tab hits the upper intake. That’s usually close to zero degrees of offset. See what happens then.

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[GoToGuy]

The computer can see the crank pos indicator, because it fired the spark through the coil output. Why isn't that lightning bolt traveling all the way though the cap? Upon disassembly, set engine position TDC #1 on crank position timing marks. Marked dist' base position, marked rotor position in dist housing. Therefore if the only moving part moved during disassembly was the dist' removal, as it will change slightly moving out of engagement with helical cut gears, and replaced the exact same way.
So if you connect the coil output wire to cap, and your quite sure the cap is aligned and slotted into base. And with plug wire fully seated in cap, shove something, spark tester, good spark plug, screwdriver into plug side of wire. Crank it! Crank 15, 20 seconds go through all 8 cylinders. No spark? But coil puts out. 1)wires fully seated in cap wells, including coil wire. 2) plug wires breaking down from handling, age? 3) has rotor gotton damaged flattened spring? 4) Dist cap aged out, or rough handling hidden damage, everybody has that "friend".
That the coil fires but the lightning isnt jumping out the plug wire side. From what you describe, thats what i would focus on. Amazingly it can be something small preventing ignition flow. Good luck.

 

[Canon Lansdell]

Any distributor tabs broken?

I’d agree that it points to the cap if the coil wire sparks but the plug wires don’t.

It should still turn over with the CMP offset being out within reason - and I’d put money on it being out by a few degrees until you can get a scanner on it to set it. Since it’s a free check, loosen the hold down clamp and twist the head of the distributor until the distributor cap mounting tab hits the upper intake. That’s usually close to zero degrees of offset. See what happens then.

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would it being off a few degrees not allow it to spark? i realize it would be a rough timing but i figured it would still spark at least.

 

[Canon Lansdell]

The computer can see the crank pos indicator, because it fired the spark through the coil output. Why isn't that lightning bolt traveling all the way though the cap? Upon disassembly, set engine position TDC #1 on crank position timing marks. Marked dist' base position, marked rotor position in dist housing. Therefore if the only moving part moved during disassembly was the dist' removal, as it will change slightly moving out of engagement with helical cut gears, and replaced the exact same way.
So if you connect the coil output wire to cap, and your quite sure the cap is aligned and slotted into base. And with plug wire fully seated in cap, shove something, spark tester, good spark plug, screwdriver into plug side of wire. Crank it! Crank 15, 20 seconds go through all 8 cylinders. No spark? But coil puts out. 1)wires fully seated in cap wells, including coil wire. 2) plug wires breaking down from handling, age? 3) has rotor gotton damaged flattened spring? 4) Dist cap aged out, or rough handling hidden damage, everybody has that "friend".
That the coil fires but the lightning isnt jumping out the plug wire side. From what you describe, thats what i would focus on. Amazingly it can be something small preventing ignition flow. Good luck.

definitely worth a try, but it seems like it’ll only crank for a few seconds before slowing and stopping itself. battery is charged. also, cap rotor and wires have maybe 8k miles on them. all plug wires are firmly in cap

 

[Canon Lansdell]

definitely worth a try, but it seems like it’ll only crank for a few seconds before slowing and stopping itself. battery is charged. also, cap rotor and wires have maybe 8k miles on them. all plug wires are firmly in cap

update, tried removing the cap and realigning button, tested for spark with actual tester, had spark but weak due to battery being low. spark plugs aren’t in the best of shape but from what i can tell still useable. tried offsetting fist’, didn’t work. checked all grounds and they’re good. checked ckp and icm and theyre plugged in good. attached are rotor button and cap.

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[east302]

Just to confirm, that’s no spark on any of the eight?


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[v0nzipper]

Check all the grounds of the motor. I missed one near the crankshaft pulley while doing heads