rb25det bogging under power in second and third

[jrb92se]

ive been having a slight problem with my car bogging down under hard acceleration and then instantly making power again. it happens for about one second about half way through second gear and then again toward the top of second gear and sometimes it will happen about halfway through third. i will be on the gas hard the exhaust is loud then for a split second it feels like the car loses power then jerks forward again, and you can clearly hear a dramatic change in exhaust note during this. i at first thought that it was detonation but i read up on that and figured that isnt the problem. the car will be running normally under hard accell. then it sounds like the car is choking or farting for a second,it loses power, then it runs fine till the top of fifth gear. it only occurs under hard acceleration and in 2nd and 3rd gears. sorry for the vauge* (spelling) explanation but its the best i could describe the problem im having. i think that it is leaning out for some reason but im probly wrong any help will be appreciated

[jrb92se]

may it be a bad coil or spark plug y/n?

[gawdzilla]

regap your spark plugs and try again

[jrb92se]

arent most plugs gapped properly when you buy them? i have ngk iridiums. i didnt think you had to re gap ngk's

[Chaos the Xile]

not always I'd regap them and try again, sounds like a coil problem to me too

[jrb92se]

where is the red light on the ecu to check for error codes its an r33 s2 rb25det. my pops says that if it is misfiring then it should be throwing code. could this blow my engine? i think im gonna take it to xat let them check it out.

[Darius]

The red light on your ecu is behind a thin film of clear tape as is the screw that you have to turn to get the ecu to blink off the check engine light.

Spark plugs do not normally come pregapped in any application. You always have to check the gap on your new plugs no matter what brand.

No, misfiring will not blow your engine unless it is pre-igniting (detonating).

[jrb92se]

darius, thanks alot for the info. im gonna have my father check it out for me when he gets home this afternoon. what is the proper plug gap?

[300Plus]

I'm having a similar problem. Keep us posted. I noticed that my wide band barries the needle at 10.0 when it happens. I think its either loosing spark (I'm running re-gapped NGKs) so ignitors/coil packs or I thought maybe it could be the diaphragm in the nismo FPR maybe punctured and when ever boost hits it flops wide open.... BUT the weird thing is when the wide band is reading 10.00 (richer then bill gates) there is no black smoke or any smoke for that matter. So I'm not sure what is causing me to run so rich under 100% throttle acceleration. Any ideas? coil packs... maf... fpr ?

RB25 series II ,12 psi (but with this problem will only hit 9psi), and Nismo FPR

Thanks guys!

[jrb92se]

i dont have a fpr or any form of aftermarket engine managment installed (pfc shipped from jap. sat.). if i turn the boost up to 12 it gets worse and doesnt happen at all at stock boost i think i may have burned up a plug awhile when i ran some 104oct. race gas, could this be the case? i feel for some reasone that it is gonna be the second or third from last plug too. what should i re-gap my plugs to. and if i need what are part nums for compatible ngk's are they the same as the z32?

[Darius]

gap your plugs to 0.8mm and slightly narrower as boost increases above stock settings. 0.8 should be good for you though.

[Darius]

With regards to running rich, I am getting about 7 mpg right now. I don't know if it is old gas or what, but we'll see how it goes on a fresh tank. These motors run extremely rich out of the box, so the PFC will definitely help tune for better gas mileage and help troubleshoot your problem.

[jrb92se]

i was talking to my pops he says .6 is good and that .8 is a big gap that will be hotter and i should probly go for .7. because its right in the middle of what you told me and what he thinks would be good

[jrb92se]

i pulled my plugs ive got some garbage autolites im going to pick up some ngk irids (for z32 turbo) what do i need to regap them too??.06 .07 .08?

[cdorhout]

I'm having a similar problem. Keep us posted. I noticed that my wide band barries the needle at 10.0 when it happens. I think its either loosing spark (I'm running re-gapped NGKs) so ignitors/coil packs

Actually, a misfire would register as a quick LEAN spike on your wideband.

[jrb92se]

the ngks are gapped at 1 mm should regap them at .8 or .6

[jrb92se]

ok i gapped them at .7 (between .6 n .8) i took it out tonight and it feels like a completely different car it runs 100 times better then before. i cant believe the guys i got my car from put autolite plugs in it, they were gapped at 1.5mm!!

[USMCgetsome]

Ok. I had similar problems with my original maf. I'd be driving and it would stutter like the motor was about to shut off. I'd let off the gas for a sec it would backfire and then resume as if nothing happened. My motor keep doing this despite replacing the cas, igniter chip, plugs. So i replaced my maf and it stopped all together. Checked these symptoms by reinstalling my original maf and the symptoms arose again. Put in the new maf and i've been running fine since. Sounds real close to what i had going on. If you'd like i got an extra maf series 1 rb25det if your interested. [email protected] this is my extra back up that was fine. I've got 3 mafs.

[gawdzilla]

ok i gapped them at .7 (between .6 n .8) i took it out tonight and it feels like a completely different car it runs 100 times better then before. i cant believe the guys i got my car from put autolite plugs in it, they were gapped at 1.5mm!!

regap your spark plugs and try again

damn, only about 100 posts later you figured out that the answer was in the first reply other than your own
Modified by gawdzilla at 10:55 PM 10/31/2006

[jrb92se]

sorry, i was just really worried about what was wrong with it, i knew i needed to check my plugs/coils and i did. i was just told three different plug gaps to run by three different people and was trying to get to the bottom of it sorry to waste the bandwidth

[300Plus]

My plugs are gapped to .8 if I remember correctly. and I'm still having bogging issues. If the Maf were going out I would most likely get some type of engine code. but I'm showing no codes. and I can confirm the voltage on the maf by using my datascan and nissan consult software. its just wierd

as soon as I hit High rpm (as in 5-7000) or the boost gets to about 6 psi I feel the car either bog or just plateau like i ran outta power. but I know this isn't the case because the car ran 5x stronger then that every day until this popped up. usually under W.O.T I'm running 12.2 a/f ratio but now it hits 10.0 as soon as the bogging hits (but idles fine at 14.8 a/f) I'm running the stock series II maf blow through so I know its not just a simple boost leak along the lines, since it could only be 2 couplers or the intake mani gasket.

Any help would be great guys. Im going to check timing via timing gun this weekend. whats the recommended techniqe as in using the white loop or not ? whats the base timing? you guys can save me some time looking through the FSM . THANKS A BUNCH GUYS I need opinions!

Kamin, think it could be the variable timing not kickin in?

[jrb92se]

i gapped them at .7 jsut because it was in the middle it runs great compared to before with the autolite garbage that was in it. also some wher in this thread it says you should get a readout from your coil of 8 ohms with an ohm meter. if you have new plugs and it still boggs you may either have a boost leak somewhere or a bad coil. check all your hose clamps and then your coils