RB25, Need help with a code 21

[Sileighty_85]

need a solid answer from knowledgeable RB guys

Lately the Engines been running like shit and running rich, I pull codes and I get ONLY a code 21 which is Ignition Signal.

Now what does this exactly pertain to? CAS? Ignitor? Coil Packs?

Now, the ECU say 21 but acts like a 13 (CTS), starts fast when cold idles pretty good until warmed up a little bit than starts running a little rich

heres the weird thing, sometimes it will kinda run rich and die on me, pull over try to crank it and no start... I disconnect the MAFS and it will fire up and idle fine (but in safe mode) Ill reconnect it and it will stumble and catch it self and run better for a while or the rest of the day.

I was thinking the rich condition could be from the CTS (ordered a new one and it on its way) cuz it also has kinda a hot start issue

did alot of searching on the Aussy forums and some ppl mentioned the Coil Packs, but nobody replies back if that was really it.

Even when it running shitty rich it boosts fine all the way through the RPM's but with noticable power loss due to running rich, also the exhaust note has changed

Ive replaced the Ignitor chip with an extra one ive had no real change

I just wanna make sure before I drop $500 on some Splitfires that this is the issue.

I know RB's are kinda notorious for Coil Packs just kinda weird that It ran fine for 2 days and died and also runs fine through the RPMS with no misfire

Im gonna pull the packs now and check them per FSM.

Thanks Guys

[redline racer510]

sileighty i tried to explain this to you before the stock coilpacks on these engine are horrible. Once the coilpacks see any radiant heat they dont operate very well. What you are experiencing isnt a rich condition, it is the lack of power output from your coilpacks which can explain the unburnt fuel/rich condition.

[Sileighty_85]

Originally Posted by redline racer510

sileighty i tried to explain this to you before the stock coilpacks on these engine are horrible. Once the coilpacks see any radiant heat they dont operate very well. What you are experiencing isnt a rich condition, it is the lack of power output from your coilpacks which can explain the unburnt fuel/rich condition.

Yeah i figured lol, I just dont wanna believe it cuz i didnt wanna drop $500 on coils haha

I checked the CP FSM says the resistance should be APPROX .6 -.9ohms Im getting 1.0-1.1 ohms, Not sure if its that bad since its say APPROX.

I did notice that i forgot to connect the CP harness ground, I did that and got no change. Now it had a hard time with cold start

AAAAAAAHHHHHHHH Damn It!!

I was hoping to take it out to the local meet this weekend....

[Sileighty_85]

alright I think i fixed it, I was checking the plugs when i saw that #6 cylinder was blacker than the others

Pulled the rail and pressureized it to find out the lower FI O-Ring was torn pissing fuel into the cylinder.

replaced the O-Ring, cleaned the plugs, Grounded the Coil pack harness, Fired right up like a champ.

well see how she does for the next few days

Will be purchasing some splitfires soon so I wont have to worry about the coil problems and since they probably do need to be replaced.

But I would still like to know more info on this "Code 21" and what it relates to more directly. Is it the fault code for the Coil Packs?

[eklips3]

alright i have to disagree with the oem coil packs being crap. they are wicked in my opinion , better then splitfire actually. so if i were you sileighty, if you are going to drop a bunch of cash on coil packs, buy oem, dont buy splitfire's or yellow jackets.

anyways going to your problem. have you ever cleaned your maf sensor ? a dirty maf sensor might lead to you running a little more rich. give it a clean, dont use brake cleaner. but it definatley wont help with code 21.

its good your changing your coolant temperature sensor cause i know there was an issue with a local drifter here in calgary and he had the same symptoms as you , maybe worse.

anyways, maybe your getting code 21 because the coil pack harness has a bad or broken wire in it. this is why your running more rich because you aren't getting the necessary power going to one or more of your coils. which will lead to all your problems with the trouble starting , exhaust note and running rich.
give it a shot man.

[Sileighty_85]

Originally Posted by eklips3

alright i have to disagree with the oem coil packs being crap. they are wicked in my opinion , better then splitfire actually. so if i were you sileighty, if you are going to drop a bunch of cash on coil packs, buy oem, dont buy splitfire's or yellow jackets.

anyways going to your problem. have you ever cleaned your maf sensor ? a dirty maf sensor might lead to you running a little more rich. give it a clean, dont use brake cleaner. but it definatley wont help with code 21.

its good your changing your coolant temperature sensor cause i know there was an issue with a local drifter here in calgary and he had the same symptoms as you , maybe worse.

anyways, maybe your getting code 21 because the coil pack harness has a bad or broken wire in it. this is why your running more rich because you aren't getting the necessary power going to one or more of your coils. which will lead to all your problems with the trouble starting , exhaust note and running rich.
give it a shot man.

Sweet thanks for the info, I know the Stock coils are good for like 500hp-ish,
But i think ppl buy the Splitfires for cost reasons, full new set of OEM ones run around 350-400ish when the Splitfires runs at about 450ish so for a couple more bucks you can get "upgrades", well see how it plays out though.

I dont remember if I cleaned the MAFS, But was thinking about it the other day. Probably will go pick up some CRC MAFS cleaner when I get paid today,

Yeah I was gonna replace it before but I tested it and It showed good back then , But im gonna go ahead and replace it so i dont have to worry about it.

I found out I didnt have the CP harness grounded so hopfully now that I grouned it It will fix everything.

Thanks for the help Bro

[redline racer510]

anyways, maybe your getting code 21 because the coil pack harness has a bad or broken wire in it. this is why your running more rich because you aren't getting the necessary power going to one or more of your coils. which will lead to all your problems with the trouble starting , exhaust note and running rich.
give it a shot man.[/QUOTE]

This also might be causing your ignition problems. Also what info do you have to provide regarding the oem vs splitfire CP? I know that they arent very good because my friends first hand experience with these cars in japan when they were new, and if you look on most RB related forums, it is one of the major problems these engines have, would really like some proof otherwise.

[GT240R]

I had a problem with missing as well and I noticed that the ignition coil condensor had melted! Replaced it and bam it was gone!!! It's in the wiring harness!

[Sileighty_85]

Originally Posted by GT240R

I had a problem with missing as well and I noticed that the ignition coil condensor had melted! Replaced it and bam it was gone!!! It's in the wiring harness!

You mean Capacitor?

Nah mines not wire harness related after I converted mine I sent it off to Wiring Specialties for Yury to inspect it.

Runs great now that I fixed the FI O-Ring, and just Cleaned my MAFS so I think its all better now.

[Sileighty_85]

Forgot to post my fix.

Turned out I had a Bad MAFS for the random dieing and hard sart. Replaced it and haven't had an issue since.

[bkt808]

im having this exact same issues and throwing codes 12,13, and 21 starts with no maf and idles rough, if i plug the maf in while its running it will run a little better but not by much. also wont start with MAFS pluged in.
my question is was the bad mafs the solution to your code 21? or was it an ignition issue??

[Sileighty_85]

Mine seemed to have been the MAFS and that coilpack/ignitor ground wire, while driving mine would randomly die now and then. Once I replaced it it never happen again.

[supersayianjim]

UPDATE 2014 JULY.

SO I have this fucking 21 falt code. and still no avail heres what I have tried.

having a really hard time with this code 21 shit. heres the deal I have a rb25det neo, I also have a nistune type 3 board. and the car has been running without ant problems. until last week. I was driving and it looked like my power was dropping when I would press the throttle(like from 12 to 10volts).
stopped the car, turned off the lights, removed the alt fuse(which wasn't broken) re stuck it back in and never got car to start again.
until.......
I sprayed the throttle plate with lots of starter fluid, and unplugged the maf. the weird thing is the car would run after some tries for like almost a minute. but when I press the gas or plug back up the maf it would die.
it would die because the fuel pump won't prime and there is no fuel in the line??
so I ran a positive wire to the pump(after I brought and returned a new pump). and the pump I had all along works.
so even running positive power to the fuel pump and trying to crank it over is no dice??
ignitor you say??



well I have ls1 coil packs with the ignitors built in so that can't be it. and again my problem lies with the fact that my fuel pump won't turn on..
here's what I have done.


-jumped the fuel pump relay

-gotten another z32 afm(brand new)

-changed the fuel pump

-changed the cas

-got a new ign switch for the key(actually needed this for down the line)

-got another z32 ecu

so I tried all of these and my damn car still won't start. iam stumped and this is getting pretty pricey and tedious seeing as iam stuck and my car is out of state on a side street.
what do you think??

[supersayianjim]

anyone??
????????????????

[Sileighty_85]

So you say you hot wired the fuel pump and still wont start?

pull the CAS and spin the rod quickly and see if you can hear the injector click.

did you pull the check to check if the plugs are wet and see if the are getting fuel?


Faulty MAFS? Big Boost leak?

[supersayianjim]

well I found out the problem spent $$$ and wasted almost 2 fkn weeks. so the problem was......

not the cas

not the ecu

not the fuel pump

not the timing/injectors etc.

somehow the fuel pump stopped priming and doesn't turn on anymore. so I have to run a 12v to one of the terminals on the fuel pump egi relay.

so in turn I just needed a fucking wire....

and thanks rad for looking up that tow for me...