8n

[rhb9z57]

8n runs but only on 2 or 3 cylinders. New plugs rotor & clip same thing.Put different cap that is good no change. Good gas flow and wonder if it is points. I thought they either fired or didnt. Not sure of problem any thoughts. thanks

 

[old]

I bet if you swap where the #1 and #4 plug wire is on the cap it will fire on all 4. Common problem to get them part way out of the firing order

 

[J Hamilton]

Do you have spark at all 4 plugs? Good compression in all cylinders?

 

[rhb9z57]

I pulled one wire at a time to put plugs in. Checked compression and good. One or two at times not firing most of time . Only running on all four at idle but not under load.

 

[Sean in PA]

Check the distributor shaft for side play. It's possible that something is worn allowing the shaft itself to wobble when you increase the throttle.

 

[Jim L WA]

Plug wires? One or two could be breaking down and shorting to ground as you increase RPM.

 

[old]

Front mount or side mount distributor?? Can make a difference as to what is wrong

 

[rhb9z57]

Side distributor. thanks.

 

[old]

This may not be the funnest way of finding the problem, but it works. Fire it up and while running grab the distributor cap with your hand. If you get a good zap from doing so the cap it self is bad and has a crack or cracks in it. BTDT and back years ago we had a 1971 GMC pickup that every time it would get a bit wet out side it would not run right. Long story short at a shop my dad took it to I grab the cap while it was running and got zapped replaced the cap and it ran like it should have