P0304 Cylinder 4 misfire

[CJ_Boxster]

ok I have a bad consistent misfire and have a p code p0304.

Now I've pulled the coil pack and checked the connection and the sparkplug and all looked fine. I put it all together and forgot to plug the wire back onto the coil pack and noticed the misfire hadn't gotten any worse or better so I think my coil pack is bad. Anyone have any input on my diagnosis?

Anyone know the readings I should get from the coil pack if I hook it to a Ohm meter?

Need this info asap cause in here at the shop and want to get this show on the road, thanks in advanced

[Loren]

Easiest is to swap the coil pack with the next cylinder and see if the misfire follows it.

[CJ_Boxster]

ok I'll try that

[CJ_Boxster]

Loren. What's the engine firing order? I wantto be sure in fiddling with the right cylinder

[RFM]

1 6 2 4 3 5 cyl.=near the waterpump.

[RFM]

cyl.1= near the waterpump.

[CJ_Boxster]

Sorry, i meant, i want to know which cylinders are which on the engine.

[juniinc]

3 6

2 5

1 4

Edited June 2, 2008 by juniinc

[CJ_Boxster]

Im not sure thats right... I pulled the connection from the 2nd cylinder on the drivers side and got a misfire cylinder #5... and the head on the passenger side looks alot further forward than the Head on the Drivers side of the engine.

So i assume its:

FRONT

4-6 | |1-3

REAR

|

TRANSMISSION

[Loren]

Reverse this as it is for a Carrera.

[CJ_Boxster]

Thanks Loren!

[tholyoak]

Reverse this as it is for a Carrera.

You don't need to reverse it, the cylinder numbering is the same between the Boxster and 911, just the engine faces the other way.

thus the numbering is

-----1--- 2---3

Front----------Rear

-----4----5---6

Not sure if that is what you meant or not Loren.

Todd

Edited June 2, 2008 by tholyoak

[Loren]

Sorry, not trying to confuse more.

I meant reverse the engine - the pulleys face the rear on a Carrera and they face the front on a Boxster.

Some folks don't realize that.

[Tool Pants]

Once you figure out which coil it is. I don't know how you test it. But.

Marvin who has worked at 2 local dealerships showed me a coil that looked new to me, but he said it was used. I asked him why he had a used coil and he said it was cracked. I have seen cracked coils before and the crack was very obvious.

I could not see the crack until he pointed it out to me. I would call it less than a hairline crack. I can see the crack in the picture only because he pointed it out to me.

[CJ_Boxster]

well my guess was a good one. Bought the beru coilpack from worldpac for $49 and removed the coil over cylinder #4 then installed it in 15 minutes. Cleared the codes and fired it up, smooth idling & acceleration now. Thanks for all u help guys.