Silva Bullit DC4

What's up, Honda-Tech. My '00 Accord V6 has been dealing with the usual random misfires (P0300, and P0301 thru 0306). Plugs have been replaced, gapped accordingly, but no ignition coil replacements yet. Here's a rundown of what has been done prior to present condition from previous codes from my OBD hand-held:

EGR insufficient flow (removed plenum, cleaned it, and EGR passage way throrughly).
O2 Sensor Bank 1 (replaced it)
ECT sensor circuit high (replaced it)
Replaced the IAT sensor as well, but did not get a code for that, just did it to be on the safe side.

Here's the thing. The problem with diagnosing the coils to see which one is bad is, the engine will not stay running when it happens. It starts and idles perfect when cold, then warms up, drives flawlessly. Then, after it gets warm and I turn the engine off and restart it (especially after letting it idle for a while), the misfire happens as soon as the engine starts, and the car won't even idle. It's not consistent though, it happens about 75% of the time. The only way I can get it to stay running, is to hurry up and apply gas while I put it in gear, then pull off. The weird thing is, after driving for about 100 to 200 yards, it clears up and does NOT misfire, and stays running as well (with NO misfire).

I really want to think that there is another problem, but can almost bet it's one of my coils. Getting it to run and not cut off so I can check them is another story. But if you guys can think of ANYthing else it may be, any input/help is greatly appreciated. Thanks.

Snoop.

holmesnmanny

My first guess is that it's heat soak and likely an ignition component...eg ignitor, ignition coil. I would pick up another ignitor and coil from rockauto. Even if it's not the cause it's good maintenance to replace those after some miles anyhow. I've had coils go bad intermittently and cause my car to die and to give ridiculously bad gas mileage as well.

Silva Bullit DC4

And you're absolutely right, and that's the route that I am leaning towards. Thinking about buying and replacing all six. I just find it amazing on these J series how one bad one can cause the majority or all to misfire at once lol.

Snoop.

Silva Bullit DC4

UPDATE:

I replaced all 6 coil packs with genuine Honda parts, and...well...drove it for about 15 minutes, idled and ran perfectly, came back into the yard (still idling perfectly), cut it off, let it sit for a few minutes, started it back up, it spat, bogged and cut off...Not again. Restarted it, held my foot on the gas and limped it to the stop sign at the end of my street (which is about an 8th of a mile away), it stopped misfiring and cleared right up while it was still running. Came back into the yard, plugged up the OBD hand-held, showed P0300 and P0301 thru P0306. Random misfire, and cylinders 1 thru 6 misfire.

At this point guys, I am basically stumped. I'm starting to blame the ECU now, but not sure if that's the issue. Crazy thing is, it doesn't do it all the time. Sometimes, she'll start up after warmup, and idle baby-smooth. Other times, she'll start up, spit and die.

Snoop.

holmesnmanny

I should have explained that on a V6 it would be wise to just swap in a new coil and test it in each one to find one that is bad. I don't think I realized originally that you were misfiring on all cylinders. It's possible that your crank sensor is either flat out bad or just caked up with gunk. You should pull it and take a look. In fact, my money would be on your crank sensor being bad.

Silva Bullit DC4

Will do, I will report back once it's done and tested. I appreciate the info.

Snoop.

MAD_MIKE

Did you verify the valves are correctly adjusted?
Too tight valves(usually exhaust), will not allow the valves to fully close. Loss of compression will cause no combustion = misfire.

poorman212

Lets not forget the early 6th gen v6's are prone to have vapor lock. Do a search for "Service Bulletin 00-024", read that and see if it sounds like the issue you are having////I don't read very well but from what I did read it sounds like it to me.

There are many write ups on what some have done to solve/reduce this from happening. One of the simplest things I've seen some do is replacing the t-stat with a new OE t-stat.

Silva Bullit DC4

I will search it as soon as I get home from work, should be useful info, and hopefully I will find the solution.

Valves have not been checked or adjusted, but it would be an ideal thing to do so, this thing has 205k on the clock. Wondering now if that would explain why it's only happening intermittently, and only at normal operating temperature or after a long idle. Did a compression test, and all cylinders were healthy.

Silva Bullit DC4

Just read the Bulletin, and it makes perfect sense. Only wish I knew about this earlier before I purchased all the other parts, lol. It's all good though, new parts aren't a bad thing, I plan on running this car into the ground anyway, never gonna get rid of it, it's been good to me.

It's a shame that the 2000 V6 is plagued with this. Some owners even got hit with the same reoccurring issue down the road. But I'm gonna try it just to get some relief, hopefully it will not rear its head again.

Snoop.

poorman212

I've seen the "mild to wild" ways of trying to deal with this.....like I said, the mild side is a new OE stat....the wild side is down to a "retro/swap" of fuel rails and lines from a Ody that use a better/return style fuel system. Also note that "winter blend" gas will make this show up more, pretty sure we are about to or have switched away from this so the issue might go away for a while....till next winter .

Again that is a SB that talks about the "2000's" but I have seen this issue on the 98 to 00's, the fuel rail/supply system changed on the 01's - at least that is what my memory tells me, can't remember exactly and too tired/layt to look it up.

I hope this is the issue and not something else but based upon the way I read your posts it seemed like the issue you are having.