cylinder 6 misfire

[Soffelony]

ive done everything i can think of i need some more ideas
its a 2000 3.4
while i was driving on the highway the ses came on and it started running rough checked it when i got home cylinder 6 misfire came up so i did a compression test it only had 30 psi..there was a hole in a valve so i put on new heads changed the plugs and wires and a bunch of other things
put it all back together and it still does the same thing except now i have 160 psi in cylinder 6
i tried another coil, ICM, fuel injector, plug, wire and nothing changes
what else is there???

[lesterl]

How does the plug look? Wet/Black/Clean/ETC... Didja get the intake gasket back on right when you had the head off? Pushrods in place good?

[Soffelony]

the plugs were black i think ill have to check again the push rods went in the same they came out all gaskets were put in right and torqued down right (my 3rd time doing these)

[534BC]

Can you at least verify the injector is firing and/or the spark is sparking at right time? It may point you to go in the opposite direction if one is working fine. Fuel, compression,spark.

[rhandwor]

Originally Posted by Soffelony

ive done everything i can think of i need some more ideas
its a 2000 3.4
while i was driving on the highway the ses came on and it started running rough checked it when i got home cylinder 6 misfire came up so i did a compression test it only had 30 psi..there was a hole in a valve so i put on new heads changed the plugs and wires and a bunch of other things
put it all back together and it still does the same thing except now i have 160 psi in cylinder 6
i tried another coil, ICM, fuel injector, plug, wire and nothing changes
what else is there???

Pull the spark plug ground it against the block make sure it is firing. Use a noid light and make sure the injector is getting power.This will help you figure what to go.

[Soffelony]

i pulled the plug again and its wet and black
i have a light that hooks to the plug and i can see it fireing and i can feel the injector working but i have no idea of how to tell when it supposed to fire

[rhandwor]

Originally Posted by Soffelony

i pulled the plug again and its wet and black
i have a light that hooks to the plug and i can see it fireing and i can feel the injector working but i have no idea of how to tell when it supposed to fire

Spray around the intake with carburetor cleaner check for an intake leak. Check for a vacuum leak something is causing extra fuel going to this cylinder. You can try going up one heat range on the plug. Double check the work you have done is everything plugged in properly. Did you route injector wiring and plug wires properly.

[534BC]

Do you know yet what caused the hole in the valve? This may point to the problem re-occurring.

[Soffelony]

i have no idea of how or why

[Soffelony]

i noticed that it happens more when its under load
going up a hill the ses will flash

[Soffelony]

any chance the computer is causing this?
is there any way to check a computer?

[rhandwor]

Originally Posted by Soffelony

any chance the computer is causing this?
is there any way to check a computer?

I think you have more of a chance of defective wiring to the coil or injector.

[Soffelony]

i found the problem a few weeks ago
it was a bad spark plug the porcelain was cracked
runs good now