jchrisf

I have a 95' ES 300 and it is sending a code P0306, Cylinder 6 misfire detected. For the past couple of weeks my car will idle rough most of the time. It drives fine at speed and only reflects the misfire at idle. Sometimes it idles fine but mostly I can feel the misfire at idle. I've searched the internet and all other information I've found with this code has had other codes associated with it.. like several cylinder misfires. oh yeah, My engine has never stalled.. don't know if that is important?

Does anyone have any advice for resolving this? I'm thinking maybe a new ignition coil but wanted to ask here first.

Thanks

GEORGE_JET

How long since the spark plugs have been replace? If it has been awhile, I would recomend a new set of plugs, 1 new coil. Make sure that you gap the plugs before installing.

jchrisf

It's been a long time... not sure how long

Should I replace the plugs first and see if it clears it up? Or is that a definate code that the coil is bad?

GEORGE_JET

Well since it is number 6 and very easy to get to. I would pull the plug and look at it. Then make the decision on the plugs. Fortunately for you it is the front bank. If you feel like narrowing it down, it is very easy. You could even swap coils from 4 to 6 if you have a scanner and can see if the missfire moves to 4.
If not the cost of a coil is not too bad. You could just change it out.

jchrisf

Thanks George... I'll give that a try. I also read in the repair manual something about checking the coil with an omh meter so I'll give that a try while I'm at it. Where should I buy my parts if I end up needing a coil?

GEORGE_JET

You can use a DVM to measure the resistance of the coils, use the next coil as reference to how many ohms the coil should measure. But be aware that just because the coil measures good, does not mean that it is good. The only positive way to verify this is to substitue. If you have a scanner, you could swap coils with another cyl, and see if the miss moves.

On that note, if you are interested, you can purchase a USB OBDII scanner that will work on all OBDII car/trucks. They run around $50, you can find them on ebay. They come in very handy when troubleshooting many problems. A good scanner will not only tell you codes, but will also tell you the values different sensors are reading (such as if you want to see the coolant temp, it will tell you in deg what the temp is. No need to even look at the sending unit or harness, unless it is off).

I purchase my parts from the local auto part store, I avoid dealerships as all costs.

jchrisf

Thanks for the advice on the scanner. I will check with ebay and see what I can find.

jchrisf

George Jet,

I was looking at ebay and there are a lot of really cheap USB OBDII scanners coming from Hong Kong. The only others I found were around $200 and this one:
http://cgi.ebay.com/ebaymotors/OBDII...motiveQ5fTools

Would you recommend the cheap ones from Hong Kong, the one in the link or keep searching for a better deal from an American vendor?

Thanks

GEORGE_JET

The higher end scanners are running over a grand. These can comunicate with other modules in the car, and control these modules. For example, if you were to replace the ABS unit, you would need to bleed the valve module. These higher end scanners can comand the ABS computer to open all valves. Same with transmissions, you can comand the valves to activate (very dangerous if the car is running).

I think the one in the link looks good, and being that it is distributed stateside, warranty issues would be much easier. I like the idea of interfacing with a PDA. You may want to talk to them to see if this will do eveything you want. If so, then yes I would recomend buying it.

jchrisf

Cool Thanks!

llcoolpass

the other way to test the coil is to measure the spark output, but I do think swapping the two coils is a good way to test the coil. seems odd just one misfire detected if it's the coil, don't you george_jet? also, changing the spark plugs is not a bad idea, could tell you how the engine is running by their condition [lean, rich, a lot of carbon, coolant from headgasket leak, etc]

about ABS, is there a way /process that someone can do without the high-end scanner, or toyota specific equipment, to get the ABS to open to flush the fluid? maybe just on some cars?

GEORGE_JET

According to my manual, 95 has 6 coils, one for each cylinder (I just double checked, to make sure). I'm don't know if any ABS systems have alternative ABS flush, my guess would be yes. My personel scanner is a mt2500, you can pick them up for around $300 on ebay. It allows bi-directional comm. It uses plug in cartidges that enable comm with different cars, subsystems. It continues to surprise me on different things it will do. (a couple months ago I found that I could change the tire size on a ford pickup, so that the speedometer would read right. It is a little spendy, but if you ever work professionally on cars, (even part time), you can write all you tools off on income taxes.

llcoolpass

well if it's got a coil over plug system, and misfire on cyl 6, 95% of the time, that COP needs to be replaced

the thing about changing tire size is pretty useful, wish could do that on all cars so easy

jchrisf

George,

I am going to swap the coils this weekend and wasn't sure how to clear the codes... just disconnect the battery for a few minutes?

PS How do you know so much about cars? It is great having you here

JSM1284

Yes, disconnect the batt, it will clear the codes.