Jump to content
SAU Community

Strange Eccs Relay Behaviour

GTSBoy

By GTSBoy,
in Engines & Forced Induction

 Share

Recommended Posts

GTSBoy Grand Master

GTSBoy

Posted
Posted

Hiyas,

Recent transplant of RB25DET Neo into R32 started off running just fine, but after pulling out the ECU to swap R34 Nistune board for a Stagea one (unrelated problem was solved by changing from R34 image to Stagea image) the car started doing something odd. I was wondering if anyone has had the same drama and if the solution is easily dupicatable.

I don't think the change of Nistune board was the cause - I just think that pulling the ECU out from the kick panel area must have done a little tweak to the wiring around the various plugs and the ECCS relay. No violence or mishandling occurred, but obviously everything got moved around and tugged a little bit.

The symptoms:

  1. With the car cold (not necessarily stone cold, just not run recently), turn the key to on. No fuel pump prime, cannot connect to ECU with Consult. Do not hear the ECCS relay click on. Obviously no power to ECU. Can crank, but not start (not surprisingly).
  2. Turn key back to off, then back to on. Pump will prime, ECU powers up, can connect. Car will start.
  3. Turn engine off. Turn key back to on, no pump prime, no ECU again....but...
  4. If you didn't start the car at step 2 above, you can turn it off and on as many times as you like, and the ECCS relay will click on, power up the ECU, run the pump prime, every time.
  5. Every time the car is started in this condition though (cold), it will need to go through the key on-off-on routine to get it to go again though.
  6. When the car is warm, ie driven up the street and back, or any further distance, the car will always behave completely normally after you stop the engine. Pull up, switch off. Turn key to on, pump primes, ECU comes to life.
  7. Let it cool down for long enough, back to the on-off-on behaviour.

I'm sure the cold-warm behaviour difference has nothing to do with the temperature of the engine. I think it must just be some electrical warmth thing - where having been switched on and running it is warm enough to do what it is supposed to do the first time.

The ECCS relay has been swapped out and the behaviour remains the same.

Interesting side symptom - if, when the ignition is on but the ECCS relay is not working, no pump rpime, ECU dead, you pull the ECCS relay from it's socket and put it back in, the relay will kick in and everything works.

Someone suggested to me that it might be the ignition switch, but I am having trouble working out how the switch can give me the symptoms observed - especially the one triggered by pulling the relay out and putting it back.

Any thoughts? Is there a likley candidate of just a single earth wire or something similar that could be responsible?

cheers

Brad

Link to comment
https://www.sau.com.au/forums/topic/399024-strange-eccs-relay-behaviour/
Share on other sites
GTSBoy Grand Master

GTSBoy

Posted
  • Author
Posted

Not really possible. Conversion of an ECU to Nistune is not quickly reversible. I would try a plain jane ECU if I had one available. If my fishing for answers here and/or the direct troubleshooting work do not turn up an answer, I'll have to drag it around to Matt's place to see if we can swap the R34 board back in (assuming it still exists in the form I gave it back to him in) to conduct the nearest test to what you describe.

Thing is, I only just characterised the complete problem (as contained in the description in OP) on Sunday, then jumped on a plane to fly away for work. Time poor, internet rich just at the moment!

cheers

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

    • WMDC35
      first time swapping rb25det into r34

      By WMDC35 · Posted

      I've done this both ways, I'd use the original loom & swap plugs on the engine side as you'll usually end up changing a lot of those anyway. Series 1 is usually non ABS which requires wiring which I can't remember how to do as haven't done it for over 15 years. The auto inhibitor is easy to bypass or in the meantime you can put it in neutral & unbolt it & tape it somewhere in the bay haha, then just wire reverse lights. I'd go straight to aftermarket ecu. A few basics are built in ignitor coils & reverse the CAS wiring, sort the plugs for whatever injectors & IAC-you can use an adaptor for the neo type otherwise the s1 will still work, use the knock sensors that suit the loom & it'll be pretty much running.  
    • MidnightR32
      Cold compression test after rebuild... should I be worried?

      By MidnightR32 · Posted

      This is for an RB20DET. Sorry for not including that. 
    • MidnightR32
      Cold compression test after rebuild... should I be worried?

      By MidnightR32 · Posted

      Welp, this is where my compression lands after my rebuild. Thoughts? I have ~6 hours on the motor. 
    • Keeper
      SAUNSW - Cruise - Albion Park Aviation Museum - 9th August

      By Keeper · Posted

      Event details are now up!
    • GTSBoy
      Another little story of weird shit happening

      By GTSBoy · Posted

      Well, after the full circus this week (new gearbag, 14 psi actuator on, injectors and AFM upgraded, and.....turbo repair) the diagnosis on the wastegate is in. It was broken. It was broken in a really strange way. The weld that holds the lever arm onto the wastegate flapper shaft broke. Broke completely, but broke in such a way that it could go back together in the "correct" position, or it could rearrange itself somewhere else along the fracture plane and sit with the flapper not parallel to the lever. So, who knows how and when exactly what happened? No-one will ever know. Was it broken like this the first time it spat the circlip and wedged itself deep into the dump? Or was it only broken when I tried to pry it back into place? (I didn't try that hard, but who knows?). Or did it break first? Or did it break between the first and second event of wierdness? Meh. It doesn't matter now. It is welded back together. And it is now held closed by a 14 psi actuator, so...the car has been tuned with the supporting mods (and the order of operations there is that the supporting mods and dyno needed to be able to be done first before adding boost, because it was pinging on <<14 psi with the new turbo with only a 6 psi actuator). And then tuned up a bit, and with the boost controller turned off throughout that process. So it was only running WG pressure and so only hit about 15-16 psi. The turbo is still ever so slightly lazier than might be preferred - like it is still a bit on the big side for the engine. I haven't tested it on the road properly in any way - just driven it around in traffic for a half hour or so. But it is like chalk and cheese compared to what it was. Between dyno numbers and driving feedback: It makes 100 kW at 3k rpm, which is OK, could be better. That's stock 2JZ territory, or RB20 with G series 550. It actually starts building boost from 2k, which is certainly better than it did recently (with all the WG flapper bullshit). Although it's hard to remember what it was like prior to all that - it certainly seems much, much better. And that makes sense, given the WG was probably starting to blow open at anything above about 3 psi anyway (with the 6 psi actuator). It doesn't really get to "full boost" (say 16 psi) until >>4k rpm. I am hopeful that this is a feature of the lack of boost controller keeping boost pressure off the actuator, because it was turned off for the dyno and off for the drives afterward. There's more to be found here, I'm sure. It made 230 rwkW at not a lot more than 6k and held it to over 7k, so there seems to be plenty of potential to get it up to 250-260rwkW with 18 psi or so, which would be a decent effort, considering the stock sized turbo inlet pipework and AFM, and the return flow cooler. According to Tao, those things should definitely put a bit of a limit on it by that sort of number. I must stress that I have not opened the throttle 100% on the road yet - well, at least not 100% and allowed it to wind all the way up. It'll have to wait until some reasonable opportunity. I'm quite looking forward to that - it feels massively better than it has in a loooong time. It's back to its old self, plus about 20% extra powers over the best it ever did before. I'm going to get the boost controller set up to maximise spool and settle at no more than ~17 psi (for now) and then go back on the dyno to see what we can squeeze out of it. There is other interesting news too. I put together a replacement tube to fit the R35 AFM in the stock location. This is the first time the tuner has worked with one, because anyone else he has tuned for has gone from Z32 territory to aftermarket ECU. No-one has ever wanted to stay Nistuned and do what I've done. Anyway, his feedback is that the R35 AFM is super super super responsive. Tiny little changes in throttle position or load turn up immediately as a cell change on the maps. Way, way more responsive than any of the old skool AFMs. Makes it quite diffifult to tune as you have to stay right on top of that so you don't wander off the cell you wanted to tune. But it certainly seems to help with real world throttle response. That's hard to separate from all the other things that changed, but the "pedal feel" is certainly crisp.
×
×
  • Create New...