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i'v posted thread befor about the coils

missfiring @ idle

i use to have it mostly when the car is cold ..

i'v changed the places of the coils ... mmm feel some diffrent .. ( dont know why )

now it miss fire lil bet ... but .. mostly .. it like losing power btween 4500 tell 5800 exactly .. only between those rev its not accelerating like it should ... after 5800 rev . it go's ok ... tell it reach 7000 ... every time it did the same .. in all gears .. (didnt try 5th gear) and by the way .. it happen some times .. some times it not ... i mean after driving for some time .. this gos off

any way

100% misfiring at idle .. but not sure if it misfire at 4500 .... (i think its somthing else)

so .. the Q is .. ?

why its only loosing power at 4500 to 5800 every time ????

is there anything special happen between those rev's ??

i really feel sick already :throwup:

plzzz help

if they r the coils that would be easy to fix ..

mod: hks filter only

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My friends car misfired between 4000rpm and 6500rpm because the spark plugs where gapped to high, we gapped them down and it was all good. Maybe check your plugs first.

...thanx for replying mate ....

i already did that ..

gap = 0.8

NGKplug IR laser iredum

heat range 6

i'v also tryed NGK R iredum

heat range 5

also did compretion ratio at home ..... its ok... lil diffrent in some of them .. (not a big deal tho)

some pic

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why its only loosing power at 4500 to 5800  every time ????

is there anything special happen between those rev's ??

mod: hks filter only

Considering your mods, that is quite strange.

With most RB25DET's running higher than stock boost, the reason there is a flat spot in this rev range is b/c of the A/F ratio's getting very rich. Timing is also retarded at this point. If your coils have any fractures in the casing, it will also misfire.

Best solution is aftermarket management or a SAFC to correct the fule mixtures.

There are quite a few threads covering this topic, search around and you will find a few solutions that have worked for others in the past...

Zahos

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Considering your mods, that is quite strange.

With most RB25DET's running higher than stock boost, the reason there is a flat spot in this rev range is b/c of the A/F ratio's getting very rich. Timing is also retarded at this point. If your coils have any fractures in the casing, it will also misfire.

 

Best solution is aftermarket management or a SAFC to correct the fule mixtures.

 

There are quite a few threads covering this topic, search around and you will find a few solutions that have worked for others in the past...

 

Zahos

thnx mate .. that makes me happy ..(coz i wanna belive that its only the coil :D )... if its only coils that would be ok .. i'll change the coils next month ... split fire coils or should i go for those kind of coils which comes away from the engin (check pic)

and going for powerFC soon ,.

if any one else have any other thoughts ... iwould like to know more ... thanxx guys ..

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or it could be anything, some one correct me if im wrong.

steve

mm .. the problem is that it comes and gos ..

so .. still not sure .... but 100% i'd go for new coils ... but no one answered my Q .. ?!

do i go for split fire coils ....

or i go for this coils which come alone away from the plugs ... the one on the pic .. i posted befor ...

thanx

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why are they 2 different spark plugs?

One is NGK IR, the other is just R. I would definately replace those plugs just from the look of them.

Gapping iridiums is ok, you just have to be carefull. The most important part is the tip, the rest is fairly durable.

Also, how tight have u put the spark plugs in?

Try insulating the coils with electrical tape aswell

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I would recomend the coils that are on the firewall (the ones in your pic) as the skyline coils are prone to failure as they get so hot!

i like that idea .... but .. do u know any good coils which is ok for the r34 .. and what convertion do i have to do to the ignition wireing .. ??

that would be a good info .. :)

thnx

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why are they 2 different spark plugs?  

One is NGK IR, the other is just R. I would definately replace those plugs just from the look of them.

Gapping iridiums is ok, you just have to be carefull. The most important part is the tip, the rest is fairly durable.

Also, how tight have u put the spark plugs in?

Try insulating the coils with electrical tape aswell

i know ... i did test the NGK R 1st ... then i'v checked the NGK IR ..

i will change them also .. while changing the coils .. ..

any info about the coils in the pic .... :) .. ?!

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why are they 2 different spark plugs?  

One is NGK IR, the other is just R. I would definately replace those plugs just from the look of them.

Gapping iridiums is ok, you just have to be carefull. The most important part is the tip, the rest is fairly durable.

Also, how tight have u put the spark plugs in?

Try insulating the coils with electrical tape aswell

i know ... i did test the NGK R 1st ... then i'v checked the NGK IR ..

i will change them also .. while changing the coils .. ..

i dont know ... exactly ... but 100% not too tight ... i can open them and close them easly .. but i know they r not lose ..

any info about the coils in the pic .... :) .. ?!

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