F100kls

hey guys, got something for you to nut over for me.
my motor is doin things that have me scared during idle it runs perfect but it has a repeated bang. its 8 months old. i thought it was misfiring so i bought new leads checked plugs they are clean.
i have been told from listening to video footage it is the exhaust valve possibly staying open.
i havent checked compression but that will be done shortly
the thing that has me twisted is when i unplug No7 it runs nice, plug it back in and it continues banging??? whos knows why
i've taken the pushrods out form 5 and 7 and they straight with no damage and the valves are moving freely.
any ideas guys

cheers kris

Sand1

Thats a stuck or bent valve, a damaged lobe on the cam or a bad lifter. If the valves are adjustable make sure they are all adjusted right. Stopping the fire from the cylinder keeps it from igniting the gas is why it seems to smooth out. Pull the plugs out and remove the left valve cover. Crank the engine by hand and watch the #7 rocker arms. A compression test will tell you if its a valve. Concentrate on that #7, thats where your problem is. My money is on the lifter or cam.

F100kls

thanks for your help. BUT it was the dizzy cap points 7 and 3 were must've having sex or something, there was a crack running between them and was giving feedback to and from. well i ruined there love live and pissed it off for a new one.

i picked up a set of top gun leads does any one praise them or have any issues or know of a better set. the old set were accel 8.8
but at the end of the day it is work truck nothing too great

cheers

Sand1

Yeah, that would do it too lol. Dang, lost another bet with myself lol. Glad to hear it was something inexpensive.

F100kls

glad that it is inexpensive x2 mate.

and who ever the tool was that tried squeezing a bosch rotor button onto a Mallory dizzy didnt help.
was on so tight had to wedge it off with the screwdriver. happy now that it has the right parts doing the right job

wizardry

thunder cords in sydney arnt bad you can tie em in nots and they dont stuff up not to good on the sterio though but hey when you have a sweet tune coming from the exhaust who cares about the radio

F100kls

how does ignition leads affect the stereo??