Ok I have a 05 tC w/turbonetics kit boosting 6psi. I have been trying to clean the codes for misfire but it keeps coming back after everthing i have tried.

Code reader
P0300
P0301
P0302
misfire between cylinder 1 and 2, random misfire

So far I purchased new 2 sets of new plugs BRK7, one step colder plugs. Gapped them at .031.
Next step i thought maybe one of the coil packs was going bad so I borrowed my friends coil packs from his clean running tc swapped them and i still get the code back after clearing it. His car didnt get any codes.

I also recently installed my Uni Chip computer and was thinking it was something in the tune, So i removed the uni chip and installed it back to factory and it still misfires.

At idle the you can hear threw the exhaust a small misfire....The AFR Gauge reads 15.9 and bouces to 15.0 because Im assuming the misfire causing that. then when i slowly rev up to about 1500 the car starts to mis like it has a cam or a messed up Honda trying to idle. the rpm bounces from 1500 back down to 800 back and forth. Once i let off the gas, it goes back down to idle. idles just fine. It doesnt seem to have lost any power but the annoying check engine light is on.

Under full throttle I cant notice a misfire.

So I was wondering if any has an idea of what it can be?
My next trouble shooting step is to remove my injectors and clean them
P.S. I have swapped the spark plugs around to see if it thro 3, 4 cylinder codes which did not
I also swapped the coil packs around too and no luck on getting it to read difference cylinder. At one time or another it did read cylinder 4 but i didnt take note of when that was when i was trouble shooting.

EDITED for the people that dont like to read the entire replies.

More to addd.... I just did a compression test and it read 100psi on all cylinder. I swapped fuel injectors from 1 and 2 to 3 and 4 to see it reads the misfire to that cyclinders


So it looks like the problem shifted from misfire to the compression.... Ever since i swapped the injectors from 1/2 to 3/4 I have not got a check engine light but I still notice a misfire problem with it rev bouncing under 2000.
Idles just fine with no problems. Every once in a while if I leave the car idling for a long period of time the car will start to burn oil causing it to smoke.

 

check your vtak sylinoid


lol jk some one correct me if im wrong but i thought the gap was .44 on the tc?

 

Did you just put this kit on? Maybe the injectors are clogged? You can try swamping them between cylinders to see if it changes your misfire.

*I just noticed that you already said injectors is the next step in the post above*.

 

i got misfire problems because i got dirty injectors... but what was suggested by my tuner (Jason from Portland Speed Industries) was to use copper plugs and gap them at .28 and everything ran so much better.

 

Yes factory gap is .044 but on a turbo application that would blow the spark out.. I will low the gap to .028 soon. but i noticed no matter what gap the plugs were at it still had a misfire. vtak????? vtec for honda??? LOL Yeah i was thinking along fuel injectors

 

More to addd.... I just did a compression test and it read 100psi on all cylinder. I swapped fuel injectors from 1 and 2 to 3 and 4 to see it reads the misfire to that cyclinders.

 

that seems a little low... my compression is 220 straight across N/A and 180 straight across turboed... but then again mine is a tC..

 

did you take all the spark plugs out when you did the test. 100 psi is not enough to keep it running very good. i 99 % on rings.

 

Out of curiosity whats your a/f under load? 1/2, 3/4, wot etc...also what does it read at cruising. Just curious

 

Right now my a/f is not 100% correct. I have been trying to fix the misfire problem so that i can fine tune. at idle is 15.9 cruising about 13.1 to 12.6 under full load 10.9 to 11.1

 

My car is a 2005 tc with 50,000 miles on the engine............... It runs fine and idles just fine. Yes all the plugs were removed when I did the compression test. I got home from work so the car was warmed up aswell. I turned it about 8 or 9 turns before looking to see what the finall psi reading was. So it looks like the problem shifted from misfire to the compression.... Ever since i swapped the injectors from 1/2 to 3/4 I have not got a check engine light but I still notice a misfire problem with it rev bouncing under 2000. Idles just fine with no problems. Every once in a while if I leave the car idling for a long period of time the car will start to burn oil causing it to smoke.


I have read on a few forums that you can poor some oil in threw the spark plug hole, 30 weight, just enough to coat the top of the piston. It will create a seal around the rings long enough to increase the psi to normal. Its said if it increases then its the rings, if it dont its the valves not seating or timing chain stretched.

 

I ran into a similar problem and actually found out there was a crack in the rubber boot that covers the spark plug, a little bit of glorified petrolium jelly, and an ECU reset I was running like a dream again.

 

my car smoked cause my tune was off, as well as it sounds like a misfire problem because there was no base map on my tune... So I'm curious if its a tune problem now...

 

@david yea man def check that tune...i dont know what normal a/f for turbo tc's typically is but your pretty rich at wot. Id take it easy so you dont melt a valve until you get it tuned. Im sure you know that though im just lookin out. Good luck with gettin it goin man

 

Not to burst any bubbles or anything but the rubber piece your talking about is attached to teh coil right? Also in the above messages/post i said i swapped coil packs with another tc and it still read the same problem. I can rule out rubber boot and ecu reset... Now on too the tune. It is running a little rich but that wouldnt cause a misfire that bad under no load. My main problem now seems to be the low compression. So far the misfire check engine light has not came on but i know there is still a misfire. I agree it could be a tune problem with it smoking but with the low compression problem I dont think the tune would have anything to do with that

 

Im going with tune, head gasket, melted valve...in that order

 

It is quite possible that it is a head gasket, and or melted valves. Improper fuel mixture over time would cause excisive heat. Right now im looking into buying a new engine..... Does anyone know if the Gen 2 xb engine is the same as the tc engine

 

Def doin a smart thing building a motor on the side.

 

Ok to update this. Come to find out the compression gauge i had was bad. it reads 215 all cyclinders. This is a year later. the check engine light for misfire comes on and off. Recently it has been coming on a bunch for misfire. Still doing the same thing. Since then I have retuned this car, new plugs. It still does the same thing. Misfire between cylinders 1 and 2 and random misfire. Im lost in what this problem can be.

 

have you done a leak down test.