98 expy, EB 4.5 misfire Im lost

moonjo · 03-24-2008, 09:13 PM

I got the dreaded P0304 code from auto zone. Anyone care to walk me through replacing a coil pack? tune up last year, not sure the guy changed that one. I am sure this is the problem after everything Ive read, I just really need a picture or something. where is the coil pack? please help me!!!

ajpletcher · 03-24-2008, 09:44 PM

follow the plugs from the head to the end and there will be the pack, some screws, electrical connector and correctly positioned spark plugs wire, and you will have yourself a replaced coil pack

moonjo · 03-24-2008, 09:59 PM

I am such a woman

can you tell me which is the number 4? I found a firing order diagram except it doesn't make any sense to me. If I am standing in front of my truck, looking towards the windshield, what plug is on what side? Oh I know I am a nightmare!! Thanks so much for you help!!

ajpletcher · 03-24-2008, 10:09 PM

on the diagram it should have the front labeled and work it way back, the front is as if you were in the drivers seat. However, dont quote me, but number one is on drivers side front, after that im not sure it either goes straight back then start on the other front again or flip flops. However, to make thins easy i would just make a drawing, showing witch wire went to witch cylinder from the coil, and then when replaced just place all the wires back in orginal order

moonjo · 03-24-2008, 10:14 PM

Good call!! I will definitely make my own notes. I did manage to replace the heater core about 5 months about or so. Took the entire dash out. Only broke one thing!! the boo switch but I don't care about that, I know what gear im in!!

I appreciate your help so much. I am going to try and just replace all the coils just in case.. I figure they are probably like light bulbs, once one goes, they all go. so expensive though. the one thing I have on my side is time so I cant complain.
Thanks so much!!

TBIRD430 · 03-25-2008, 01:02 PM

On my '99 the coil pack is on the front of each head/valve cover. #1 cylinder on all motors is ALWAYS the forward most cylinder (looking at motor from the top). At least that is what my father always taught me.

phantom_smack · 03-25-2008, 01:24 PM

#4 is on the passenger side all the way in the back under the heater hoses.

moonjo · 03-25-2008, 03:17 PM

Thanks to each of you for replying. Ive had some time to get my head together and think this out. With the code I got, "misfire #4 cylinder" I went and looked and sure enough, theres a huge hole in one of the hoses. I put my fingertip in it and the truck idled down to almost normal. It wasn't actually the hose that had the hole it was the small connector (rubber piece) that connects three hoses. I replaced that, but I am still getting that awful sluggish ride and the horrid missing.

So what I gather from endless reading is, I am looking at one of several things,

1. Coil pack the whole top piece ( I think) that could have a crack.
2. The plugs, I had these changed (whole tune up, less than year ago) I don't know if the guy that did it really changed the #4, if I am correct in thinking the #4 is the hardest one to get to.
3. injectors -- totally lost on these
4. low fuel pressure -- how can that be?
5. cat converter? rotten egg smell? only smelled that once and it was not for long and now not at all.

Now, My question, where would any of you begin the cruel process of elimination? Do I get the coil pack and pray that's the culprit, its not too expensive. Seems fairly easy to replace. go all out and have the plugs all changed again and actually watch and ask for the old ones back? I just don't know where to begin. Im for sure not afraid to be under the hood. Just need some guidance. I have time. Just can't stand my 'baby' being ill.

ANY suggestions will truly be appreciated!!

moonjo · 03-25-2008, 03:30 PM

And with knowing now that the #4 is back there and thinking that I did actually have those heater hoses off a few months back to replace that heater core (what a headache that was) maybe that whole thing about the coolant leaking into the plug or coil whatever its called is right... Im going to try and post some pics of the whole heater core issues, just for kicks.

ajpletcher · 03-25-2008, 06:22 PM

Quote:

Originally Posted by TBIRD430

On my '99 the coil pack is on the front of each head/valve cover. #1 cylinder on all motors is ALWAYS the forward most cylinder (looking at motor from the top). At least that is what my father always taught me.

I don't take this baddly or as im a know it all, but that advice isn't always hold True. For example, I had a 66 plymouth with a 318 wedge, not a typical 318 very limited, only made for two years, and the #1 cyclinder was on the right side, in the middle. DONT KNOW WHY JUST WAS ... DONT SHOOT THE MESSENGER. and i only found that out because i spent six mounth trying to figure out why the hell it woudent start, when i did an intake and head replacement.

So Your father is mostly right, but dont always count on it.