Thread: backfiring out the carb?

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Just got my motor put back together, now trying to get it running. All I have been getting is backfiring out of the carb. Ive tried turning the distributer both ways and keep getting the same thing. Any suggestions ?

Im running a HEI ignition 350 in an 82 K20 pickup truck.

Originally posted by nystreetscene
Just got my motor put back together, now trying to get it running. All I have been getting is backfiring out of the carb. Ive tried turning the distributer both ways and keep getting the same thing. Any suggestions ?

Im running a HEI ignition 350 in an 82 K20 pickup truck.

Well it could be 180 out, have some plug wires crossed, or have a valve too tight Try pulling #1 plug and rotatiing the engine till the piston is at tdc. the best way to check if your 180 out is to have that vavle cover off and watch your valves. as the piston starts to come up the intake should close and at tdc both valves should be closed. Line #1 plug to that point. Just for reference point I usually have the cap and rotor pointing to #1 cylinder when I wire it. Remember, don't wire it like a ford, chevy criss-crosses. Just a suggestion.

I re-ran my wires. They were way off. Now I get smoke and gas blowing out of the carb. If I were to have my vacuum lines run wromg what would that do?

I should probably add that from what ive been told the motor has a cam(no specs), it has a wieand intake mani and I recently added an MSD HEI module. Nothing has changed since the motor was last run except the distribuer and wires were taken off and put back on.

Well I switched the stroke and now its popping out the exaust instead of the carb but it still isnt starting up

More questions: for a chevy small block with HEI igintion do I want the rotor facing the #1 cylinder or do I want it facing straight forward? Also when the #1 cylinder is at TDC, where should the rotor be relative to the number one plug wire spot on the cap?

With #1 at TDC compression stroke, the rotor points to #1 wire in the cap.Firing order18436572, cylinders 1357 drivers side, 2468 passenger side.

I figured out what the last problem was. I was starting with the rotor facing the the #1 cylinder and only turned it clockwise from there. I turned it a little counter clockwise of my starting position of it pointing at #1 and the thing fired rite up and ran GREAT.