Jump to content
SAU Community

Error Code 21 On Bnr34

Alecci

By Alecci,
in General Maintenance

 Share

Recommended Posts

Alecci Apprentice

Alecci

Posted
Posted

I've been rebuilding my R34 GTR following a crash during a track event some two years ago.

I've modified most of the engine, basically only leaving the bottom end standard.

For a complete spec list, please visit this link and scroll down below the pictures. All parts used are brand new.

For some time now we've been trying to start the car. We've run diagnostics on it and gotten some error codes, and we've managed to sort them all out except for code 21 (primary ignition signal).

I've searched the forums for other threads describing the same problem, and while the search turned up a lot of results for error code 21, none of the threads has dealt with problems such as mine (i.e. the car will not start at all).

We have spark on all cylinders, and we have fuel going into the engine. Ignition angle is 16 degrees. The starter turns over quickly and the car sounds like it wants to start, but the closest thing to a running engine we've achieved is a lot of back-firing in the exhaust.

I'm a real newbie when it comes to troubleshooting cars and fixing problems, but my guess is that one of the following are broken or not functioning properly:

- cam-angle sensor

- coilpacks

- AFM's

Any thoughts? I've posted this question on a number of other forums, but I don't seem to get any help. Having spent the last 2 years rebuilding the car, whereof the last 2 months just trying to get it started, I'm close to losing heart and taking a sledgehammer to the car in order to smash it just for the sheer satisfaction of the act. Help is desperatly needed!

Link to comment
Share on other sites
GeeTR Grand Master

GeeTR

Posted
Posted

I checked the link, nice setup man, looks smooth :blink:

If its complaining about the primary ignition signal, Id assume that to mean the CAS isn't behaving correctly. I'm not too familiar with RB26 CAS's, but id assume its a photodiode and chopper disk setup. 360 (=20) home slots and 6 trigger slots. If "Primary Ignition Signal" isnt refering to the whole CAS, maybe just one of those ouputs is broken, as i didnt think a RB would even fire without a CAS. I guess the obvious question is, have you tried a different CAS?

I'm just just thinking aloud here :(

GoodLuck

Link to comment
Share on other sites
Alecci Apprentice

Alecci

Posted
  • Author
Posted
I checked the link, nice setup man, looks smooth :(

If its complaining about the primary ignition signal, Id assume that to mean the CAS isn't behaving correctly. I'm not too familiar with RB26 CAS's, but id assume its a photodiode and chopper disk setup. 360 (=20) home slots and 6 trigger slots. If "Primary Ignition Signal" isnt refering to the whole CAS, maybe just one of those ouputs is broken, as i didnt think a RB would even fire without a CAS. I guess the obvious question is, have you tried a different CAS?

I'm just just thinking aloud here :D

GoodLuck

Hi mate,

I don't have any clue whatsoever as to how the CAS is constructed, nor in which ways it could be broken to the point where the car will not start.

I've not had nor will have any chance of trying a different CAS. There's only about 12 BNR34's in Sweden altogether, and none of them are close to where I live. Being a delicate, rather expensive and crucial component of the engine there's no way I can borrow one either.

The same thing, of course, goes for the coilpacks.

Being a bit low on funds after spending some money on the rebuild of the car, I'd hate buying new stuff that's not really needed.

Many thanks for your reply, I really appreciate it.

Cheers!

Link to comment
Share on other sites
blind_elk Grand Master

blind_elk

Posted
Posted

Error codes in Nissan ECUs are persistent, ie they "hang around" for something like 50 start cycles. Try clearing (resetting) the ECU, see if you still have the error code.

If you have spark, then the CAS is working correctly. That also rules out the coil packs. And most engines will start without an AFM.

Do you have fuel "going into the engine" because you have fuel at the rail, or because you have seen the injectors working?

Are you sure the cams are set correctly? You had the crank at TDC when you assembled the cambelt?

Link to comment
Share on other sites
Alecci Apprentice

Alecci

Posted
  • Author
Posted
Error codes in Nissan ECUs are persistent, ie they "hang around" for something like 50 start cycles. Try clearing (resetting) the ECU, see if you still have the error code.

If you have spark, then the CAS is working correctly. That also rules out the coil packs. And most engines will start without an AFM.

Do you have fuel "going into the engine" because you have fuel at the rail, or because you have seen the injectors working?

Are you sure the cams are set correctly? You had the crank at TDC when you assembled the cambelt?

Diagnostics tool and ECU has been reset/cleared between starts. We also removed the cable to the CAS, and then we would only get error code 11 (cam angle sensor). When CAS was reconnected, we once again only get error code 21.

Fuel is going into the cylinders, the spark plugs got very wet prior to lowering the fuel pressure. The injectors still open 8.0 ms when cranking the engine, some people guess the reason for that is choke (fuel enrichment for cold starts). Fuel is still going into the cylinders after lowering the fuel pressure. If I'm not mistaken, the car would not be back-firing if there's no fuel present?

Crank was at TDC and we double, triple and quadruple checked the position of the cams prior to assembing the cambelt.

Link to comment
Share on other sites
GeeTR Grand Master

GeeTR

Posted
Posted (edited)

The fact its spitting code 11 when the CAS isn't present, and a 21 when it is... I got my money on the CAS. Have you got access to a oscilloscope to check its output maybe? Could the loom be damaged between CAS and ECU?

Edited by GeeTR
Link to comment
Share on other sites
Alecci Apprentice

Alecci

Posted
  • Author
Posted
The fact its spitting code 11 when the CAS isn't present, and a 21 when it is... I got my money on the CAS. Have you got access to a oscilloscope to check its output maybe? Could the loom be damaged between CAS and ECU?

Just like you said, the fact that a non-present CAS gives code 11 and a present one gives code 21 is what also made me suspect that it may be the CAS that's malfunctioning. Otherwise I think the first error code would still show up, right?

The wiring could be damaged I guess, but it's nothing that meets the eye at least.

I'll check access to an oscilloscope.

I'm very grateful for your input!

Link to comment
Share on other sites
Alecci Apprentice

Alecci

Posted
  • Author
Posted

The car finally started this morning. It was the CAS... It probably took a good smacking in the crash (no damages were visible until we opened it up).

Thanks for your assistance, guys!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Roy
      R32 GTS/GTST non driven wheel speed

      By Roy · Posted

      Another complicated thing is to run Z32 alloy hubs which have wheel speed sensors for ABS. You need different tie rod end, and you need new bearings on the upright etc. I did that as part of a major refresh when my front kingpin bearing flogged out., Alloy was a little lighter, runs a bigger bearing , gives a few extra mm in wheelbase as it moves the wheel forward in the arch (cant run crazy but can still get 8ish comfortably).   All in all glad I did it but was a head fark as tried it once and abandoned it the first time. sav man swung his spanners at it and got it working so using his guidance on GTR/Z32 tie rod ends etc and the required mismatch of parts was able to make it work.  Probably a 2k upgrade all said and done :(   I think the best bet is just look around your front wheel and see what you can pick up rotationally. You see old Escorts, E30s etc all get very creative with front uprights and the humble old angled alloy bracket.
    • Butters
      Garrett G-XRace Range

      By Butters · Posted

      Big claims here.  Any links up on the website ?   
    • Butters
      RB gearbox options

      By Butters · Posted

      If your HP goal is reasonable and you are not drifting. Buy a new R34 box.  If the above is not true, buy a wrecked R33 box and put a gearset in it.  CD09 are not as strong as you think and the cost of / mess around of the conversion puts you in gearset territory.    Also the deal above is awesome,, get that  
    • dbm7
      Got this r31 silhouette flood car to rebuild.

      By dbm7 · Posted

      Just got back from a little hands-on with a G58 Baron....I was thinking about this... ..best I can figure it, that pinny was tail-ended ...I didn't really think about the wiring, because all that mattered was the tank and pump cradle (I think I mentioned the pump itself I couldn't vouch for)...which didn't matter, as you said you'd be replacing the pump anyway.... ...'for some reason'....and I imagine this is the panel shop's doing... they've replaced the cradle wiring with a metre of 7-core trailer loom, and attached the loom plug (from a different car) to that. The actual cable run from the top of the pump cradle, to fuel pump harness end in boot, is maybe 60cm in length...so I've no idea why they did this... ....the connector in the boot of the pinny, is not going to help you here...because in theory, it should still be present on your car. On top of that, because they've done what they did, we have no idea which colours of the trailer cabling, have been connected to what on the fuel pump cradle (pump +/- , shield, fuel guage/low-level senders)... ...this means, best approach is to remove the pump cradle, and re-work it now ...not later. That is, if you were going to replace the pump, do it, replace the soft lines at the same time...and sort the wiring out (replace that trailer cable with the wiring loom off your old cradle)...
    • GTSBoy
      Fake ARP bolts?

      By GTSBoy · Posted

      Well, maybe not. The main feature of Chinese manufacture seems to be incredibly variable quality, coupled with an apparent willingness to find a way to see even the stuff that fails QC. So the military could still take the cream of the production run and somehow sell the "sellable but not really useable" stuff to the stupid round eyes on the other side of the world.
×
×
  • Create New...