Jump to content
SAU Community

Recommended Posts

Hey everyone my battery light came on last night in my R34 while I was driving around town and I got to see it for a few seconds before all of a sudden my revs just died out and my car died, then immediately came back to life. The light would then intermittently turn on and off and the car died once or twice more then it stopped, and for about an hour nothing happened, it just drove normal. After this hour it happened again when I was just about home so I parked up and have left it alone today.

I tested the alternator this morning and it was charging at 13.8v and I checked my battery and that was holding 13.8v also while the car was running. Does anyone have any ideas of what this could be?

Mods:

RB25/30

ViPEC

Plazmaman Plenum

3076 on a 6boost Highmount

50mm Turbosmart Wastegate

Sard Injectors

Intank 044

Battery Mounted in boot (I checked the earths and connections on this and they looked good)

Any help will be appreciated.

Thanks

Also check your charge rate with your high beams, a/c fan, and brake lights on.

Need to see what the charge is doing under load.

Could still be a faulty alternator, possibly voltage reg on its way out.

But as mentioned, check your battery terminals, and earth points first.

Then go from there.

Good luck.

Sounds like the alternator or volt reg.

Really need a dc clamp meter to test it properly. Volt meters are handy but can give rricky/false readings.

if it was the alternator or reg the engine wouldnt die immediately as it still has the battery to run off. ecm would prob switch off between 8-10 so there would be ample time

sounds like something loose or even a short in batt cables

Hey guys, checked all those things and everything seems fine. The light came back on yesterday and so I tested the alternator and it was only charging at 11v. So I'm going to get it replaced as it seems to be an intermittent problem with that.

check the belt tension aswell? could be slipping

Once more, intermittant alternator wouldn't cause the engine to cut out like the OP describes... It would continue to run just fine off the battery for many more km's until the battery voltage drops to something crazy low like 8v or whatever the ECU starts getting confused at.

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


  • Similar Content

  • Latest Posts

    • Increasing overlap will bring the torque down earlier (and make your idle sound sick lol). Worth a shot (if you dyno time) to experience a bit (providing you are confident your valves won't kiss your pistons). Is to just take off 5 degrees across the boosted area of the map, and then retard the exhaust cam let's say, 3 degrees at a time and then overlay all the runs with VCT on all the way and VCT off as soon as you make positive pressure. Ideally you would have a total of 6x overlays to looks at 0 exhaust & VCT off once manifold pressure is +ve 0 exhaust & VCT on all the way -5 exhaust & VCT off once manifold pressure is +ve -5 exhaust & VCT on all the way -10 exhaust & VCT off once manifold pressure is +ve -10 exhaust & VCT on all the way Just leave your O2 wideband closed loop on for all of the boost area & RPM, and hopefully there isn't too much fuel correction needed and the Haltech is fast enough to compensate (I do this, then apply the correction to the main table). Getting that overlay data should give you a good indication of what to aim for.
    • So, my main limitation here is that the car does not have an oil pressure sensor by default, just a switch. As part of my tune I bought an oil pressure sensor upgrade so I now have access to oil pressure levels and logging rather than just the boolean behaviour of the switch but this means I need to use the tuning app to display this value. So, this rules out using any other app on the iPad. The app will also flash when pressure drops which is a nice feature. I have replaced the centre screen with an Android one, which is awesome for Android Auto, but I think it might be too far away and out of my line of sight. I might add some gauges to it this weekend and just see. I guess if its just temp and oil pressure I can make them massive! 🤣  
    • This is what the look like normally. Except we only got the 2 doors locally
    • Back pressure is not really a function of the exhaust itself, but the turbine/housing. So the question/point remains valid. I would be fitting an EMAP tapping point and seeing what is going on in the exhaust manifold before committing to throwing boost at it. Flow. No intercooler is actually rated for continuous operation at any power level wrt temperatures, as they are no actually capable of shifting the required amounts of heat on a continuous basis. They get hot during a pul, then dump some of that heat into the external air (and some back into the internal air) during off load moments/periods). You probaby do need a bigger core, given the power level you're already at is somewhat above the "rating" of the cooler. Put pressure tapping points either side of the core (which possibly you already have, if you have a boost source near the compressor outlet and tapping near the throttle for existing purposes) and report on delta P across the core.   I haven't done the mass flow calculation to see where you would be sitting on the compressor map at the ~450is rwkW level we're talking here, but if you look just at the PR you're running at, which is ~2.8-2.9, then you have a really really wide swath of the compressor map to run in, and so long as you were making between about 45-75 lb/min of flow, you should have really good comp efficiency, with the ideal being betweem 55 and 65. I can't see the need to shift drastically on the map to get better results.
    • Welcome 🙂 The ER34 wheels and slight lowering suit the R33 sedan really well. I'm firmly in the 'keep it stock, at least on the outside' camp.
×
×
  • Create New...