Rb20 Missfire On 16psi

[black sky]

Hi People

I had my car on the dyno at Dr drifts and she was going real good right up until 16psi where she started missfireing. We regapped the sparkplugs to .5mm and we also ran direct power to the coil packs and we still got missfire. I've got 5 splitfires and 1 standard coil but the standard coil lookes like it's in good condition. does any one have any ideas why it's misfiring??? i want to run my car on 19psi and this is shiting me now any help would be great.

Cheers

anthony

[Green_s13]

has the standard boost cut been removed?

[black sky]

has the standard boost cut been removed?

Yea it's running a microguess with avcr so yea the boost cut is set at 20psi

Cheers

Anthony

[Green_s13]

hmmm strange the only things i could think it would be are fuel pump or spark plugs, what type of spark plugs are you running?

[black sky]

hmmm strange the only things i could think it would be are fuel pump or spark plugs, what type of spark plugs are you running?

I'm running ngk's which dr drift gave me the fuel pump is a walbrogh (spelling) and the A/F rations were fine

[supadan]

i have no i dea but 19 psi on a rb 20 how much power you expect to lay down man

[lebostyles]

what sort of turbo you running?

[black sky]

i have no i dea but 19 psi on a rb 20 how much power you expect to lay down man

The rb20 was making 222rwkw on sam's (dr drifts) dyno on 16 psi so i was hoping to make about 240-250. I've gtot a gt30 500hp turbo with a .63 rear A/R. The car goes good but would love to have it make 250 expecially with the red line set at 8300 rpm

Cheers

Anthony

[-SKYLINE-]

Mate, gett rid of the walbro!!! they are nothing buttt trouble in jap cars. I sounds like itssssss definatly fuel or possibly a coil break down. Some times the coils get too hot and stop working for a split second. DO you know what cylinder its missing on?? Check your plugs. Youll see one of them will look different than the other 5. Get your self either a GTR or NISMO pump ---->>>> NO WORRIES!!

[black sky]

Mate, gett rid of the walbro!!! they are nothing buttt trouble in jap cars. I sounds like itssssss definatly fuel or possibly a coil break down. Some times the coils get too hot and stop working for a split second. DO you know what cylinder its missing on?? Check your plugs. Youll see one of them will look different than the other 5. Get your self either a GTR or NISMO pump ---->>>> NO WORRIES!!

It's defintally not the fuel pump it's ignition break up. like i said before i do have one standard coil and all the rest of them are splitfires. So do you think it could be because they are geting to hot??

Cheers

Anthony

[mad082]

probably that stock coil.

[Green_s13]

it would say it is the standard coil pack then as stated before pull the spark plugs out and have look at them one of them will be very black.

there is another possiblilty if not the coil pack it could be that under load i.e. above 16psi you might have an injector which is a bit leaky and you are getting too much fuel in one cyclinder, do you have an aftermarket fuel reg?

[R31Nismoid]

500hp turbo is a little too big for just 240rwkw... better off with a smaller on

anyways, if the plugs are @ .5 then i say you have coils that are not working, or not getting the right voltage

[black sky]

500hp turbo is a little too big for just 240rwkw... better off with a smaller on

anyways, if the plugs are @ .5 then i say you have coils that are not working, or not getting the right voltage

The plugs are getting direct power from the coils so it's definatlly getting 12V from memory all the spark plugs looked the same. Do you guys think it might be one of the split fires that are breaking down?? or standard one. As soon as it hits anything above 16 psi it just starts stuttering badly due to ignition breake up.

What hp rating would be good to get 250 rwkw from a turbo i mean like a 400hp or 450hp???

Cheers

Anthony

[R31Nismoid]

a GT30 is just undue lag on RB20

have a look here, 58page thread on it all:

http://www.skylinesaustralia.com/forums/in...8229&hl=260rwkw

Its long, but a good read.

Have you tested the coils to see if one is no good?

[BezerkR32]

Are you still running the ignitor? they can cause missfire when they start to fail.

it would say it is the standard coil pack then as stated before pull the spark plugs out and have look at them one of them will be very black.

there is another possiblilty if not the coil pack it could be that under load i.e. above 16psi you might have an injector which is a bit leaky and you are getting too much fuel in one cyclinder, do you have an aftermarket fuel reg?

[BHDave]

I'd check your plugs and see what heat range they are first. If they aren't 7's or 8's then swap them first.

I suppose the other thing to consider (and i think this is what bezerkR32 is getting at) is that the ignitor isn't in the best condition and is starting to fail as it gets a bit hot.

Depending on the version of the microtech you have you can throw all the stock ignition stuff away and run external bosch coils which should give a considerable improvement to the spark, but in all honesty the stock system with splitfires should be sufficient at your power and boost level.

[black sky]

I'd check your plugs and see what heat range they are first. If they aren't 7's or 8's then swap them first.

I suppose the other thing to consider (and i think this is what bezerkR32 is getting at) is that the ignitor isn't in the best condition and is starting to fail as it gets a bit hot.

Depending on the version of the microtech you have you can throw all the stock ignition stuff away and run external bosch coils which should give a considerable improvement to the spark, but in all honesty the stock system with splitfires should be sufficient at your power and boost level.

I've got bkr6e spark plugs but the car runs fine without a problem right up untill 16 psi no misses no nothing so do you think it could be the ignitor??

the microtech that i have is a lt12.

maybe i should change the 1 standard coil that i have to a better one as i have like 5 spair

Cheers

anthony

[BHDave]

I had to drop to a 7 heat range plug once i got up around 17psi otherwise i had a miss. 7 allowed me to run up to 20

[black sky]

I had to drop to a 7 heat range plug once i got up around 17psi otherwise i had a miss. 7 allowed me to run up to 20

Dr drift did put in another set of sparkplugs as well and he gapped them to .5 i think the were 7E's but we still got the miss fire. so do the 7heat range plug handle more heat?? what sparkplugs should i get so i don't have to worry about missfire at all??

Cheers

anthony