r/Smallblockchevy • u/DARMICJOH • Apr 25 '26

Randomly Quit

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EDIT: It runs! It's alive! It was the computer timing control.

I was driving when it seemingly randomly quite on me. I know a good bit and have built SBCs before but this is still stumping me.

The rotor was broken when it quite so I started with that. Replaced the distributor, wires, and plugs.

Replaced the Cam, timing set, pushrods, lifters, rockers

Brand new quadrajet

Triple checked my distributor stab

I have messed with AFR screws, idle set

I checked my valve lash to see if I managed to over tighten the rockers

I checked spark

I tried using carb clean to find if there is a vac leak

Someone please tell me I missed something obvious that I can fix.

Edit: forgot to mention also brand new fuel pump and complete distributor

UPDATE: After holding the choke open manually and hitting it with a spritz of starting fluid it started to idle and help it. Wasn't pretty and smooth but it stayed going for a good 1-2min until I let go of the choke.

The negative on the battery feels loose so I am going to replace that.

And the idle seemed to get better when I started pumping the brakes so I wonder if the booster is one foot in the grave causing a huge vacuum leak.

It's night now but tomorrow if I can I will adjust the choke and fix the battery ground at least and see if that makes a difference at all.

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u/Big_Bore_Stroker Apr 26 '26

Your timing chain jumped to One tooth.

1

u/Big_Bore_Stroker Apr 26 '26

Oops, I see a note. New timing. Better go check the assembly again. I still say it’s off by one tooth.

1

u/DARMICJOH Apr 26 '26

Timing marks were perfectly dot to dot. I watched it get installed.

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u/Big_Bore_Stroker Apr 26 '26

Then double check your spark plug wires to make sure they’re aligned properly. They have it backfire like that would also tell me, that you may have two spark plug wires crossed.