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View Full Version : *help* - the misfire woes



ultraflip
11-29-2005, 07:39 AM
:tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff:

hey everyone... here's the deal:

car in refrence: 2004 Lancer Evo GSR
Mods: Dr. Gray Stage 1+++++ Eleventy Billion Empire Strikes Back yada yada yada
Topic: MISFIRE

The Story:
Not too long ago, the p0300 misfire code came up... changed plugs that were 45k miles old (original stock ones)... it was changed to the Denso IW22 plugs...

good for about a week...
yesterday.... doing a normal pull... boost spikes to 1.7... but holds for a bit... and misfires at the same time... *wierd*... so i let off... and don't do it again...

tried again this morning around 5:30... boosted to 1.5.. minimal spike... but misfired the whole time at full boost... next thing you know... SERVICE ENGINE SOON light haunts me

P0303 Cylider 3 Misfire Detection:

What the crap is going on???? Plugs were not gapped as i was under the assumption that iridium plugs are pregapped...

can someone please put some input on this... i'm at a loss right now....

regards
-flip

kimletrim
11-29-2005, 07:55 AM
They say they are pregapped, but when you actually measure the gaps, they are all different. I like to double check spark plugs regardless of which one's I am putting in. Just be real careful with the iridiium plugs. Meaure the gaps on the plugs first and then torque the sparkplugs down properly.

ultraflip
11-29-2005, 10:22 AM
bump...

thanks for the input kim

GokuSSJ4
11-29-2005, 10:45 AM
lay off the 87 octane already!!
how about trying 100 octane, to see if that helps...
Also you might be running to lean, from what we discuss on your 91 octane map...

ultraflip
11-29-2005, 12:23 PM
indeed... i am now laying off the 87...
the gas tank has been drained... and the car is on 91 right now... yet more problems have arised

after further review... and contacting very valid sources... they've stated that my settings for my 91 map are not too lean... although drastic, for the modifications on my car, they are not lean...

EVOla_VIRUS
11-29-2005, 12:32 PM
just a couple of thoughts...how are the plug wires? is the resistance within spec?

The IW22's dont have the projected nose like the NGK's BPR's...could that have an effect on misfire for any reason (i.e. inefficient spark patttern?)

Just throwing up some ideas 8)

ultraflip
11-29-2005, 12:35 PM
thanks for the input...

right now.. i have stock coils... factory coils if you want to call it that... 45k miles on them... haven't really had problems w/ them since i changed my plugs... not really sure on how to test them

the iw22's do have the projected nose... ;)

EVOla_VIRUS
11-29-2005, 12:41 PM
Interesting...i ran with IW24 for a bit and were flat as a board and easy to nail.....i bought the BPR7EIX and they had a small protrusion raised higher....oh well...i like my ngk's :)

the coils should have a procedure of checking whether they are in spec...i would imagine it would be checking resistances between connection pins....lets see if I can find something :)

EvoPwr
11-29-2005, 04:27 PM
indeed... i am now laying off the 87...
the gas tank has been drained... and the car is on 91 right now... yet more problems have arised

after further review... and contacting very valid sources... they've stated that my settings for my 91 map are not too lean... although drastic, for the modifications on my car, they are not lean...


wow he finally listened to me about the 87 O0

j_nizzle
11-29-2005, 04:43 PM
indeed... i am now laying off the 87...
the gas tank has been drained... and the car is on 91 right now... yet more problems have arised

after further review... and contacting very valid sources... they've stated that my settings for my 91 map are not too lean... although drastic, for the modifications on my car, they are not lean...


wow he finally listened to me about the 87 O0


i doubt scot gray will run into these problems...

Blak94GSX
11-29-2005, 05:54 PM
Actually lower octane fuels misfire less. You would have a bigger problem on 110 leaded than 87 octane if it was really fuel related.

P0300 codes are unrelated to the tune, but if it truly misfires (stutters at full throttle) then it is usually a spark plug gap problem. Gap the plugs to .024 and try that. If it still misfires then you might have a boost leak.

Macky
11-29-2005, 09:06 PM
there was nothing to gap after i saw the plug :grin:

ultraflip
11-30-2005, 08:15 AM
resolution:

spark plug for cylinder 3...

Insulator is cracked
Symptom: Misfiring
most likely because i didn't gap the S.O.B....

mitsubishi also stated that the wrong plugs were in the car... i'm now sporting the stock NGK's... hopefully this helps my car out

EVOla_VIRUS
11-30-2005, 10:07 AM
Just for shits and giggles...here are the specs for the plug wires and coil (from Mitsu) *:)

Spark plug wires: Limit 19kOhm; if past, replace

Primary Coil Resistance Check: Place 1.5 V source between terminals 2 and 3; check for continuity between terminals 1 and 2. If yes on continuity, coil is fine....if no, replace.

Secondary Coil Resistance Check: *Measure resistance between high-voltage terminals of ignition coil.... Standard value: 8.5kOhm - 11.5 kOhm

Spark plug check: (Stock vehicle) *0.7mm - 0.8mm (0.028in - 0.031in) * *Limit: 1.0mm (0.039)

ultraflip
11-30-2005, 10:08 AM
yeah... this is my second encounter w/ misfire... i checked for boost leaks... no problems... i really can't point out what the crap caused this episode... no signs of anything failing as of yet... although my car feels strong... it doesn't feel as fast as it was before... but then again... richened the crap outta my map after this episode... i need to retune

GokuSSJ4
11-30-2005, 10:55 AM
same here Ultraflip,. i had misfire 2 times couple days ago.* my oem NGK are only like 2 weeks old. my spark gap are fine and there's no side of boost leak, i already did a test too.. sofar no misfiring yet. maybe it have to do with the weather? my Evo is also an 04 GSR.* i reset my bettery and turn down the boost from 21psi to like 20psi, i car feel a lot stronger for some reason.

what type of boost controller do you have ?
remember that when the weather is cold, with a MBC you will boost abit more then when the weather is hot.

Skiracer
11-30-2005, 11:14 AM
When i was having misfiring issues at high RPM's, i made my gap smaller to .024. Then, after that, my high RPM misfiring was gone, but i began to have misfires at low RPM's. So, i just made my gap a bit wider to .026 and seemed to work fine.

ultraflip
11-30-2005, 11:15 AM
what plugs are you using simoun?

Skiracer
11-30-2005, 11:22 AM
i was using the OEM equivelants iridiums: NGK BPR7EIX

GokuSSJ4
11-30-2005, 12:46 PM
no simon, your mudflaps will not help cris get rid off his misfire...

Evolution.VIII
12-02-2005, 04:34 PM
Have you ever run injector cleaner through the car? Maybe that injector isn't firing as effeciently as it needs to. I know its unrelated advice, but just thought I'd throw it out there for ya.