455 has begun to bog with any throttle

Coil must be throwing sparks to trigger the light. Engine running, or engine cranking with the ignition "on". If you're just testing the light, clamp the pickup to the coil wire if there is one. If you have a coil-in-cap HEI, then #1 plug wire like normal. IF the light doesn't work, try another plug wire. Or two others.

Best Idea: Test it on an engine that RUNS.

Looks like you need to switch the timing light from "Tach" to "Timing", which is probably done with the rocker switch. Nice light. More modern than mine by a long shot.

 

Thanks man appreciate the feedback. Hope everyone has a good holiday season out there

 

Test light strobe works. Verified on uncles truck

Moving forward:

Running Schrukeys tests: some light fuel mist shot from cylinder 1. I verified my plug wires are fine. Checked ohm resistance so i did that correctly. The plugs showed what looks like a bit of oil on them. Picture attached of that. Firing order is matched to previous cap and double checked against searches here and such. Pretty confident that that is all good. I also ran a wire directly from the battery to the coil.

Was just about to do Schurkeys spark test w this HEI tester i found. Distributor cap and rotor are clean and set correctly as well. Rotor spins flat and normally. Tried to fire it up just to check everything and it ran! Then it made a loud grinding sound and i had the gf cut the ignition. The car shut down like normal, despite my direct wire to the distributor. Shall i continue running the spark test? Thanks again guys

 

Pics here

 

Also. My valve breather dripped a few times. Not sure if thats thats cause for concern or not

 

Think i figured it out. GF didnt leave the key turned for the 3 or 4 beats to build fuel pressure before hitting the accelerator. I gave it another shot. Ran fine. Then continued after i pulled the key. Had to disconnect the battery. Fair enough. So will do Schurkeys spark test.

 

Don't leave the 12 volt direct to the coil on! It will burn up the points.

 

Yeah i killed it real quickly but i was just runnin thru the battery of tests and info i was given by Larry and Schurkey. Its the HEI not sure if that matters

 

Got good white spark off the plug wires

 

What spark tester are you using?

Interesting that the weights in the centrifugal advance look like they used to be installed "upside down". Do you know the history of those weights? Were they pulled from a different distributor?

The weights and pivot pins need to be inspected. Looks like the pivot hole in the one weight is worn oblong. Common for the weights and pivot pins to be worn beyond serviceability. No-one ever lubes them, so they run "dry" for tens of thousands of miles.

 

This kind right here is what i found.

I dont know anything about the distributor or how it was set unfortunately. I just checked some wires for spark and ran out of daylight. Will test the distributor according to your suggestions tomorrow as well.

Anything i need to do with these weights and pivots i can try of course. Thanks

 

Points? What points? He has HEI. The 12v wire was to eliminate the possibility that the resistance wire for the points was not bypassed correctly when someone converted to HEI. When “hot-wired” like he did, in order to shut the engine off you have to remove the temporary jumper wire or disconnect the battery. It’s best to remove the 12v jumper.

 

Time to flip the weights and check the timing. Either someone has the distributor in one tooth off (advanced) and tried to compensate by retarding it as far as they could, or the timing is retarded.

 

Here’s the way I used to check spark on GM HEI distributors:

Remove any spark plug wire at the spark plug, use an HEI tester connected to ground and crank the engine looking for spark jumping the gap. If the spark jumps the HEI tester gap (25kv), then you could be 99% certain that spark is not the culprit in a no-start situation. If you are all alone and can’t see the tester, listen for the rhythmic, unmistakable snapping of the spark jumping the gap.

If there is no spark, use a jumper lead on the “tach” terminal, attach a simple 12v test light to the jumper lead. (If the tach terminal is being used for a tach, disconnect the tach wire at the coil). Crank the engine. The test light should rhythmically blink. If the test light blinks and there is no spark, the problem is in the secondary ignition, IE cap, rotor, wires and/or plugs.

If the test light does not blink when cranking but is on steady, the problem is in the primary side of the ignition (pick-up coil or ignition module), and this is assuming the distributor is turning while cranking the engine. There is some testing from here to determine which one (pick-up coil or module) is bad here, but 95% of the time it was the module. Look for broken pick-up coil wires too.

If the test light does not light when cranking the engine, then the coil is shorted.

Try to test as least invasively as possible. I don’t like the testing method posted above where the cap is removed to test the coil. You are disturbing things and may end up going down the rabbit hole.

There are other possible “odd-ball” scenarios, but the majority of HEI no-start problems can be quickly diagnosed with the testing that I’ve outlined.

 

Just tossing this out there..... unless I missed something, your factory wire that goes to the "B" terminal on your distributor doesn't have 12v. You hooked a 12v jumper wire directly to the battery and it runs fine. You found your issue. What are you still diag'ing?

 

Read post 1, and then it was the no-start.

 

I do. It hasn't done it again. I restarted twice when checking spark. Think it was my starter and the gf cut ignition too quickly.

When im diagnosing is that now it IS running... Just poorly as all hell at the moment. Its been rainy all morning so havent done any more testing thus far. I was getting good white spark from my plug tester off the plug wires thus far but hadnt checked all 8 yet. So, flip the weights and pivots? Ill look into this. I also havent yet checked the rest of the distributor parts yet according to Schurkeys directives just yet. Thanks guys.

 

Also i have a little GE meter and that timing gun i just bought but no test light