P1316, P0304

[thejaw77]

I am getting a P1316 (misfire causing excessive emmisions) and a P0304. The battery is good and I'm getting spark. New coil packs. I'm running champion copper spark plugs and 8mm kingsbourne wires. Compression checks out ok. New fuel injectors, fuel filter, and fuel pump. I have tried +4 spark plugs then went back to champions. I run 91 octane. I'm hearing ticking and gets faster when accelerating. Any ideas???

 

[DownUnder]

First off you need to add your vehicle information in your post. Year make model.
Next you need to use the search option....

Now, have you checked your crank position sensor? The P0304 sounds like it could be a bad spark wire or plug.
Just because the wires and plugs are new doesn't mean they are working the way they should. Check them out and make sure you are not missing an issue there.

 

[thejaw77]

96 Discovery SD, Altia Silver, 4.0 V8, 93000 miles...When I pulled all plugs this weekend they are all buring the same except #4. This plug is fouled with carbon and has a slight hint of oil....slight. Dry compression is low at 135psi. Wet compression is 170psi. If correct, my piston ring is worn...allowing oil to bleed into the combustion chamber. Haven't checked my crank sensor. Would a worn piston ring cause hot running temps???

 

[range_time]

this could also be a head gasket, my compression went way up when i did a wet test and it was the gasket.

Try swapping the plugs from a known good cylinder to your bad one. If that does not help try swapping the wires from one side of the motor to the other (or try another wire just for a test) if its a bad wire or plug this should show it.

other than that could it be the coil?

Dave