[superrag]

what can happen to a 396 big block when you leave off two spark plug wires and start the engine....we had a nice smooth car before this and now it running really bad..knocking almost...we can't find problem any ideas? before we pull engine....thanks

 

[rustbucket79]

Did you mix up the plug wires when you reinstalled them?

 

[superrag]

no, we put the plugs on and it runs bad, so we tried new plugs and wires and still runs bad ...Help Ideas..what could of happened

 

[rustbucket79]

Sorry, I meant that is it possible that you swapped the wires for the cylinders. Like mixing up 5 and 7. Double check the plug wire routing and positioning on the cap.

 

[BlueSS454]

A number of things can happen. If the distributor cap is bad, it will cause thew engine to fire in the incorrect order. PLug wires can be switched, bad spark plug, etc. Do some checking before pulling the engine out. Also, make sure the coil has 12 volts. Low voltage can cause a weak spark and cause it to run bad.

 

[Mike]

Brent ,is this an HEI ?
They tend to burn a hole in the center of the rotor when there's nowhere for the spark to go -IE :

when you leave off two spark plug wires and start the engine

 

[Bubba's 69]

You have likely got some wires mixed up in the firing order. It does not hurt to have wires disconnected and run the motor.

I was in a hurry to get mine started once and I forgot to put the plugs in on one whole side. I started it and it ran terrible, then I heard the "psst, psst, psst" from the cylinders without plugs. oops:clonk:

4 cylinder BB

18436572

 

[superrag]

no, we replaced the old dib. with a HEI After this problem and we still having inturnal noice in engine

 

[Tom Mobley]

running for a while with 2 plug wires off won't damage your engine.

What else were you working on when you originally pulled the 2 plug wires? Sounds like a couple wires reversed or something else got changed while you were doing whatever you were doing. What prompted this deal in the first place?

 

[Dave Birdwell]

Leaving #8 off is a good way to destroy a module. Ask me how I know. A bad module will cause running problems before it quits.

 

[BUBBA2711]

Leaving #8 off is a good way to destroy a module. Ask me how I know. A bad module will cause running problems before it quits.

X2.:yes:
You don't even have to leave the wire off just the boot,and you could kill the module. Ask me how I know!:yes: