dead cylinder

Hope you guys can point me in the right direction.:confused: The number 2 cylinder on my 302 is not firing. I have changed the plugs and wires on the engine and still getting a miss. When the engine is running you can pull the number 2 wire and it doesn't change anything. I ran a compression check on the cylinder and came up with 120. The only thing I can think it could be is maybe the valves. Any help will be greatly appreciated.

 

You need to check the other cylinders to campare readings and that should give you a clue if it is a valve sealing issue. A big ass vacuum leak around that intake port will also cause this. You said you changed wires and plugs did you inspect the cap and rotor??? Good luck

 

I replaced the cap and rotor when I did the wires and plugs. The compression readings were pretty much the same on all the cylinders. I put a vaccume gage on the engine and everything looked good there. I sprayed some carb cleaner aroung the bottom of the carb and around the intake to see if I had any leaks and all that was good. Its got me scratching my head.

 

double check your firing order 1-5-4-2-6-3-7-8

 

firing order good. Checked and double checked.:confused:

 

maybe pull the valve cover on that side and see if a rocker loosenedup or a pushrod broke. 120 psi isn't great compression, but its not bad either depending on engine equipment and condition,but the cylinder should fire okay with it.

 

When you pull the plug wire, did you place the end near a ground to see if you were getting a spark from the wire?

If so, pull the plug itselft, put it in the end of the plug wire boot, ground the plug threads to the block, turn the engine over to see if the plug itself is firing.

It could still be a valve issue, but I'd rule out electrical first.

Just my .02 (fwiw).

Gluck

 

If its not electrical, I'd bet money on a valve not opening. Like suggested, pull the valve cover, spin the motor, and see what they're doing.

 

Happened to mine once. Dead lifter. Was getting on it pretty hard and on shutdown I could tell it was running funny. Big car show that weekend and I was going to it. Popped valve cover and saw a rocker never moving. Never made it to the car show, but did get the car running right.
Dan

 

When I had my factory heads on the car I pulled up a rocker stud and had the same situation. I did have a mild cam and I heard it happen --when I revved it up but it pulled up a intake rocker stud. They are pressed in (the factory ones) and not too hard to pull up. It sounds like that or some other broken valvetrain piece.