RB25 seems like its holdin back.......HELP!!!!!

[Jo240sx]

IgotI have a RB25 in my 240, with apexi neo afc, apexi boost controller, FMIC, Apexi exhaust......yady yady yady....anyway when i punch it to the floor it seems like it misfiring or pinging of some sort...... it holds back a lil.... i was thinkin it was my intake(not enough air coming in) but ill kno when i get my new one if thats it.......anybody got a AFC that i could get your tuning number from ya cause i still havent gotten the AFC tuned....... Someone Help...... I need Help....lol PEACE
Modified by Jo240sx at 10:36 AM 9/30/2007

[240z4u]

Yeah its probabally your intake

Get a timing gun and set your base timing.

For gods sake don't drive it until its fixed if its actually knocking.

Evan

[mrose7716]

check for codes too..

[Jo240sx]

Yeah its probabally your intake

Get a timing gun and set your base timing.

For gods sake don't drive it until its fixed if its actually knocking.

Evan

Yea its not knocking it sounds like its pinging when i punch it.... but i just cut my old filter up (AEM) that was on my KA and screwed it on the new MAF.....so once i get my new APexi i hope it work.....MY mechanic said that if i use the AEM one it would restric the air coming in......... thanx for your help....peace

[Jo240sx]

check for codes too..

MROSE WHAT DO U MEAN CODES?????

[eh?]

Get rid of the afc and your mechanic too.FYI knocking is also known and pinging. So how exactly does the car sound? Did you set base timing?Are cams aligned correclty?Are the coils cracked?What plug and what size gap are you running?How much boost are you running?

[Jo240sx]

Get rid of the afc and your mechanic too.FYI knocking is also known and pinging. So how exactly does the car sound? Did you set base timing?Are cams aligned correclty?Are the coils cracked?What plug and what size gap are you running?How much boost are you running?

lol..... its only when i put it to the floor it starts to hold back like theres not enough air coming in, i watch my RPMs and it will be at like 6000 drop 100 the back up then drop again.....timing was set, but i never though about the coils. can i just tell buy looking at em if there cracked...cause then i guess there would be no spark and im running on 5 cylinders. im running Iridium plugs no gap they didnt need it.....should i gap and how much??? when my boost is at 9 its ok but if i put it up too 14 its all waked out......let me kno....thanx

[S12_hybrid]

Let me guess they are NGK iridiums gapped at 1.1? I had them in my 200sx (RB25det series 2) and it absolutely hated them. No top end power, etc etc...

Get a set of ngk coppers and gap them to (I think) .7mm.

Cross reference this with the RB parts thread, it supplies a plug part # and proper gap.

Also, try dropping a cylinder at a time and seeing if the rpms drop - if they do youve got a bad coil. Sometimes it only happens under load which is hard to recreate when you're stationary!!

Good luck.

-Dan

PS - "Codes" are ecu fault codes. I'm suprised you didnt know this.

PPS- x2 on the "ditch your mechanic".

[matafied]

Is it just me or has there been like 87 of these same threads in the last 2 months misfire, breaking up, holding back, oh and now Knocking lol hmm check plugs, check coils, check timing, check for boost leak ahhhhhhhhh!

[Darius]

If you are not tuned and you are cranking the boost to twice what the stock map was based on, you'll be lucky if there is enough fuel to keep it from knocking up top. #1 check the gap on your plugs, #2 verify your base timing is set at 15*, #3 TUNE IT!

BTW an air filter is not going to make that big of a difference that you would feel it. Your mechanic is pulling excuses out of his a$$.

[eh?]

lol..... its only when i put it to the floor it starts to hold back like theres not enough air coming in, i watch my RPMs and it will be at like 6000 drop 100 the back up then drop again.....timing was set, but i never though about the coils. can i just tell buy looking at em if there cracked...cause then i guess there would be no spark and im running on 5 cylinders. im running Iridium plugs no gap they didnt need it.....should i gap and how much??? when my boost is at 9 its ok but if i put it up too 14 its all waked out......let me kno....thanx

I do recommend getting rid of the afc and I also recommend lowering your boost with that stock turbo.There's a lot of possible issues with your car. You must lower your boost unless you want to destroy the stock turbo (it's stock right?)It's possible you are maxing out your stock maf.The coils can be cracked, hairline crack that are barely visible and only loses spark at high load. Sometimes you can see burn marks on the coil.Also make sure your plugs are gapped to .8m or less. I use ngk BCPR7ES don't get a -11 ngk plug as those are pre-gapped to 1.1 mm as opposed to .8mm

[Jo240sx]

I do recommend getting rid of the afc and I also recommend lowering your boost with that stock turbo.There's a lot of possible issues with your car. You must lower your boost unless you want to destroy the stock turbo (it's stock right?)It's possible you are maxing out your stock maf.The coils can be cracked, hairline crack that are barely visible and only loses spark at high load. Sometimes you can see burn marks on the coil.Also make sure your plugs are gapped to .8m or less. I use ngk BCPR7ES don't get a -11 ngk plug as those are pre-gapped to 1.1 mm as opposed to .8mm

Where did you pick those plugs up at?? i went to AutoZone and they aint got em...... i kno the ones im using didnt need to be gapped so there prob 1.1.... im gonna go your way and see if that works... i would get rid of the afc and go with a power fc but no $$..... yeah i try to run about .65 bars on my boost controller i havent put it up cause i dont wanna mess sumthing up......
Modified by Jo240sx at 9:14 PM 9/24/2007

[eh?]

http://www.clubplug.net/

I did find BCPR7IEX's (iridium gapped at .8mm) at a local pepboys, though I had to go behind the counter and find them myself.

[Jo240sx]

http://www.clubplug.net/

I did find BCPR7IEX's (iridium gapped at .8mm) at a local pepboys, though I had to go behind the counter and find them myself.

I checked the coils today they didnt seem like there was any cracks or burns, but i ordered plugs last night hopefully they will fix the problem.....

[Jo240sx]

Well i put my new plugs in today and it did help a lot....but its still doing it, not as much tho...... well i guess im gonna have to take it on a dyno and tune it..... damn afc, im gonna start saving for a power fc probly wont be for another month or two....... any other suggestions on how to fix it???

[silviasgp06]

asking what codes are????not knowing about coil problems???14psi on the stock turbo??? im not trying to flame you or be harsh to you in anyway, but did you do any research on the RB motor before you bought and swapped?

like i said before i mean no disrespect but im a little confused.but lucky for you people are nice on this forum and will help

good luck.

but:if coils are bad search "RB Engine Coil Retrofit" and there is a coil upgrade you can do for like $100 that involves using a GM coil pack that i plan on doing when i get my rb25.

double check everything else people said though. Have fun!

[Jo240sx]

asking what codes are????not knowing about coil problems???14psi on the stock turbo??? im not trying to flame you or be harsh to you in anyway, but did you do any research on the RB motor before you bought and swapped?

like i said before i mean no disrespect but im a little confused.but lucky for you people are nice on this forum and will help

good luck.

but:if coils are bad search "RB Engine Coil Retrofit" and there is a coil upgrade you can do for like $100 that involves using a GM coil pack that i plan on doing when i get my rb25.

double check everything else people said though. Have fun!

yeah dude im new to this stuff.... i remember checkin what was wrong with my KA by turnin that screw on the ecu..... is that what your are talking about codes???? Im used to straight up plug wires.....and the turbo has been to 14psi once....

I checked my coils and there doesnt look like there any cracks, burn, yady yady yady........but that GM upgrade coilpack sounds good for the $$.... I did a lil research before i bought it but i was thinkin RB20, RB26 had mostly all the problems.... also i havent gotten it on a dyno to tune my afc..... Thats my next step if that dont work then new coils....I love this site so many people with RB25 and there always willing to help someone out....thanx to all

plus my mechanic doesnt kno what the F*** hes doin....he might have the fastest 300zx but that dont help me with my RB...... thats why im on here so i dont need to go to a mechanic cause id rather learn and do it myself....holla

[eh?]

I'm in orlando.. Bring it to me but I have to charge...j/k

Make sure your timing is correct. Make sure the CAS is right in the middle. You don't need a timing light. When the cas is in the middle timing will always be at or very near 15° on a stock ecu. If not something is wrong.Also make sure your knock sensors are hooked up.

[rb 90 240]

I was about to buy a afc of a local dude here but maybe not after reading this. What wrong with the afc on the rb motors? I see people saying the power fc is the way to go but isnt that like $1200?

[Jo240sx]

I'm in orlando.. Bring it to me but I have to charge...j/k

Make sure your timing is correct. Make sure the CAS is right in the middle. You don't need a timing light. When the cas is in the middle timing will always be at or very near 15° on a stock ecu. If not something is wrong.Also make sure your knock sensors are hooked up.

Holy F***, today some stupib B**** tried to make a left right in from of me ( i was going 60) i missed her but i F******G hit the rear end of a Tahoe and F****D my hole right front up...... bags went off....messed up my dash where it came out......... Damnit this sux..... engine is OK that i can see until i rip the hood off 2morrow......wouldnt start back up when i tried to move it, rad is all up on the crank pulley.....rad done, optima batter done, fuse box done, hood, fender, headlight all done, busted nose (i guess thats why they made seatbelts) ...lol nooooo my baby!!!!!!!!!!!!

posted some pics up!!!!!<center></center>
Modified by Jo240sx at 10:35 AM 9/30/2007

[rb25drag]

I'm in orlando.. Bring it to me but I have to charge...j/k

Make sure your timing is correct. Make sure the CAS is right in the middle. You don't need a timing light. When the cas is in the middle timing will always be at or very near 15° on a stock ecu. If not something is wrong.Also make sure your knock sensors are hooked up.

B.S!!!!!!!!!! I dont care wat you say about the CAS being in the middle. I garantee you its no wears near 15 degrees. The slightest movement of the CAS will knock it off +-2 to 3 degree's. Dont ever F*** with the timing unless you have a light. or else you will screw something up.

I know you just crashed your car which blows a load!!!!!!!!!

My car run like a piece with NGK plugs, I went and got A/C delco number 4 cold plugs and it runs like a champ now. If your running the stock plugs there prob a 7or8 out of a 9 hot index. When you crank the boost you need a cold plug or else it detonates, Plus if your cranking the boost without changing the timing to match thats a big NO NO!!!! be smart and tune as you change. and if you up the boost do it a pound at a time to keep from killing your motor.

[Darius]

I'm in orlando.. Bring it to me but I have to charge...j/k

Make sure your timing is correct. Make sure the CAS is right in the middle. You don't need a timing light. When the cas is in the middle timing will always be at or very near 15° on a stock ecu. If not something is wrong.Also make sure your knock sensors are hooked up.

I'm not so sure that is true about the CAS. Mine is wayyy off to one side and set to 15* base timing with a timing light. Could it be because my block and head were decked during the rebuild?

That sucks so bad about your car. I'm sure the woman's insurance will cover whatever you say was damaged especially if your insurance company is behind you. Did she get a ticket for failure to yield or anything that would indicate fault on her part?

Sorry this is getting off-topic a bit.

[l0nestar]

Wow man, that really blows

[eh?]

B.S!!!!!!!!!! I dont care wat you say about the CAS being in the middle. I garantee you its no wears near 15 degrees. The slightest movement of the CAS will knock it off +-2 to 3 degree's. Dont ever F*** with the timing unless you have a light. or else you will screw something up.

.

You really think +2 or +3 degrees of added base timing to an already conservative map is going to mess anything up?

I said it should be at OR NEAR.

You're an idiot.
Modified by eh? at 7:18 PM 10/1/2007

[eh?]

I'm not so sure that is true about the CAS. Mine is wayyy off to one side and set to 15* base timing with a timing light. Could it be because my block and head were decked during the rebuild?

imo likey the light is reading incorrectly. It's a common occurance that the light will read double rather than actual.

The cas should always be at or the middle on a stock RB25.

I guess I should have said in a pinch you can get away without the light. But obviously any self respecting DIY'er should have a timing light and yes it should be used.

as much as I hate skylines australia:http://www.skylinesaustralia.c...ition"If your cam timing is correct set the bolt centred with respect to the cas and that is approx 15-20degree's advance.If you have to dial in what looks like excessive advance or retard (hence not near centre) then your cam timing is out."

I've encountered this many times over the years and it's true.
Modified by eh? at 7:15 PM 10/1/2007

[Darius]

I am wondering if I used the light properly...I took the signal from the loop but ran the wire through the induction pickup one time. The thread on SAU makes it sound like they ran the loop through the pickup twice, is that correct? Now I'm wondering if I am running really retarded base timing...(7*). Damn that would piss me off!

[cdorhout]

[eh?]

The type of timing light is important too due to direct ignition. My cheap red Actron light is accurate but I have to make sure the lead is hooked correctly. It's been working well for 4 years.

I don't use the loop, I always use the white wire going to #1 coil. It's the same wire but it's been accurate for myself.

[Darius]

Great now I'm all paranoid.

[eh?]

Go ahead a try using the #1 lead and just set the cas in the middle..Make sure you're looking down at the right angle too if you want to be exact..