Car Wash -> 2Miles -> P0302

[ymic]

Trying to be brief, went to the car wash, got down the road a bit and the car started stumbling, no power at all. Wideband a/f is 15.7-16.0 at idle. Check engine light was blinking, scanned it at Checker. Got a P0302 Cylinder #2 misfire.

Mods:
-nano
-fmic
-cdfp internals
-deno itv22's
-corksport tbe
-standback
-vta inlet
-ssqv vta

Troubleshooting:
I've moved the coil packs around, and i threw a brand new set of plugs in, it is still misfiring on the same cylinder.

Any ideas?

 

[oaklandopen]

try switching fuel injectors? couldn't be water in the intake cuz then you'd have problems with all your cylinders.

maybe just sit with the engine running and start wiggling the wires around and see what happens, maybe something came loose

 

[ymic]

try switching fuel injectors? couldn't be water in the intake cuz then you'd have problems with all your cylinders.

maybe just sit with the engine running and start wiggling the wires around and see what happens, maybe something came loose

it's getting plenty of fuel, the tip of the plug is wet with gas when i pull it out. There's no spark.

does anyone have a wiring diagram for the ignition system?

 

[oaklandopen]

if you had an ammeter and some T-pins you could find out if its an electrical problem before the spark plug. every coil pack should be getting 13ish volts

 

[ymic]

if you had an ammeter and some T-pins you could find out if its an electrical problem before the spark plug. every coil pack should be getting 13ish volts

What is the pinout of the 3 wires going into the coilpack? Are they energized all the time? Or only when it is running? I have a fluke multimeter and other electrical stuff, I just need a wiring diagram and what should be present.

 

[Bravnik]

Check the wires coming from the coil in Cylinder 2 where they go into the sleeve of the harness. When my coil blew the wires looked good but when we cut back the harness cover a bit the wires were fried just inside.

Also check the coil that was in the cylinder 2. When mine blew it had a bubble at the base of the coil head where you could tell it was melted. I doubt your coil is fried though if the misfire didn't follow it.

There is also a post somewhere by someone that had a SB with the plug and play and water was leaking down into the connector and caused all kinds of issues.

 

[ymic]

I pulled the standback and same story.

 

[ymic]

Any ideas? I hate driving the honda when its nice out....

 

[Bravnik]

I pulled the standback and same story.

I think the problem was not with the SB but with the Plug and Play Harness not having a good seal and allowing water to get down into the pins of the ECU and causing it to rust and such. Look at the pins on the ECU and see if there is any rust which would indicate water getting into the ECU which could be your issue.

Also, did you check the harness wires coming from the Coil? The bare wires go from the coil into the sleeve of the harness. Mine melted inside this sleeve. We cut it back a bit and the wires were fused together in there.

 

[Bravnik]

Another thing to check is the clamp on the turbo inlet. The clamp that goes from the Turbo Inlet to the Intake has been known to rub the wires at the bottom of the ECU and rub into them which can also cause all kinds of issues.

I know when I installed my SRi that my clamp was rubbing my ECU wires coming out the bottom to the point that it rubbed through the tape and was starting to rub on the actual wires before I caught it. I had to re-adjust my clamp and re-tape the harness.

 

[controlo]

sounds like water in the intake to me. the same thing has happened to me more than once. same code. right after washing my car.

 

[Sport6]

Don't have the wiring of before the coils but do have how you can check each coil to see if they are still good.

 

[C.A.T.A.P]

i have had the same problem but my code is a p300. i went as far as to buy 4 new coil packs and it helped but still have problems and havent figured out what is going on with the car.

 

[ymic]

Bingo, the #2 coil is melted on the bottom. I verified with the testing procedure. I haven't had time to check and see if the harness is melted but the dealer said i have to have Mazda roadside tow it in.... ugh.

 

[SPEED305]

make sure they send you a flat bed. hopefully the harness or anything else is not damaged.

 

[Bravnik]

Bingo, the #2 coil is melted on the bottom. I verified with the testing procedure. I haven't had time to check and see if the harness is melted but the dealer said i have to have Mazda roadside tow it in.... ugh.

If you are lucky then the wires are not fried. In my case they were fried all the was through to the lower harness as well. $3500 worth of warranty work and a new harness shipped that took a couple weeks to get.

However, now it is just fine. The way they explained it to me (I'm not an electrical engineer) is that the path to the coil is fused in a step up fashion. However the path back is not and if the coil burns out and sends a lot of power back the other way, it will fry the wires as they simply can't handle that much power and the fuse going back is a 30a fuse!

Good luck!

 

[Sport6]

Demodding before you bring it in?

 

[ymic]

Demodding before you bring it in?

yessir.

completely stock now.

dealer replaced the coil pack, wires were ok.