Jump to content
SAU Community

Recommended Posts

R34 gtr boost limiter?

Hey guys, so pretty much important myself a bayside blue 2000 r34 GTR, been super keen to get this car for the last couple months waiting, and today was the day to pick it up and drive it home, first 10 minutes car was a dream looked felt amazing just wanted I wanted, then... a problem started so  symptoms are this,

- start the car turbos/boost everything runs great, give it some gas and the turbos spool up to about 1 bar ( which I didn't think was stock boost settings but anyway ) 

then 5-10 minutes later I will go to just Accelerate normally and it will start to spool but when it gets to around .4 bar it will cut all the boost and the car will act like it has a speed limiter and not getting any air in, after that I had to keep driving the car in a higher gear to make sure it never gets into + boost because it would loss all power and not run, in 6th gear it will spool to around .2-3 bar at about 110 but as soon It gets over that bam cuts out again.

if I turn the car off and back on, problem immediately  goes away and car runs perfect again, then all of a sudden will start up again a couple of minutes later, watching the boost gage on MFD I can see it climbing into + boost then all of a sudden drops fully down ( with no wastegate noise or anything ) and the car staves for air.

any ideas of what it could be would be amazing, it's kinda put a downer on my excitement for getting this car, and really hurts when I still have a 1000km trip home with no boost 

 

Link to comment
https://www.sau.com.au/forums/topic/470406-r34-gtr-boost-limiter/
Share on other sites

Bummer, but these old cars need TLC like any other. 

If it happens only when the car is warm it could be vac line that expands, could be bad sensor (I once had a bad CAS and an O2 that would only play up warm). AFMs with dry solder joints can also play up when warm if they are only just started to go. 

You need to pop the bonnet and get in there for a look. Dos a boost leak test, get a field services manual and multimeter and test some sensors. If you are not comfortable with those basic testing things take the car to a workshop that knows RBs. 

Factory ECU? You can buy a consult cable (I think like $100?) and download ECUTalk for free.

 

  • Like 1

Seem to fix the problem, have driven about 600 more Kms and if hasn't gone into limp mode so that's always good, I pretty much unplug all the easy to get to cables blew them out and plugged the back in, someone I know also thinks that it could be because the car wasn't driven for 7-8 months that it could have build up somewhere and driving has fixed it 

 

cheers heaps for advice and help 

time to enjoy the car now 

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

    • Consider a 35 too...
    • He's right ~ there is no 'magic' with stuff like this ... it is more likely that in the process of looking for the short, the loom/wire 'incidentally' got moved in the process, thus removing the short ~ now, that maybe a wire (in a loom) rubbing against the edge of some grounded metal, that's worn through the insulation, causing the (now intermittent) short to ground. If one wire in a loom has been damaged in this fashion, it's reasonable to presume that other wires beside it may have also be damaged, and now exposed...you can bet the green crusty copper corrosion will start... ...that'd be a pisser, Murphy's Law steps right in as GTS observes...but worse, something like that is easier to find when shorted...ie; unplug bulb and fuse, and put multimeter in continuity mode so you get constant beep, and carefully poke about hoping to find if some movemet of the harness stop the beeping.... ...it's still all a bit Arnie tho' ..It'll be back... 😃
    • Yeah, but knowledge of one wire's insulation worn through to short on earth implies the possibility of other wires doing the same. I had my power steering die, because the wire that runs to the solenoid valve on the rack runs in the same loom as the power wire for the O2 sensor. And when the O2 sensor/wire did something stupid and burnt part of that loom to death, the only indication was the shit(ter) fuel economy and the heavy steering. It took deep excavation of the looms in the bay to find the problem. Not wear through in that case, but similar shit.
    • Ah, I thought he'd wired it to one of the spare ECU inputs! Too long ago since I read that post, ha ha. I've been arguing with radiators, harmonic balancers, alternators and rust since reading it.
    • Correct. The ECU cannot read oil temp. (Well, I think it probably can in some situations. I did have the thought of potentially repinning the ECU when I was doing oil pressure). I am using this into the MPVI dongle, so that the MPVI dongle can read oil temperature. It is attached to a VDO gauge which is obviously calibrated to whatever curve the sender actually is using. This would be easy if I could setup a table of voltage to temperature like many sensors, but it appears I cannot do this and can only setup the transform rule which appears to be Input (voltage) x Multiplier, and add an offset. This to me means it MUST be linear. So it may be a complete waste of time wiring this into the ECU. The idea was that the MPVI3 has standalone logging. I wanted to use this instead of a laptop with serial cable (for wideband) for long datalogs. Given the wideband also has electric interference, I may never trust this either in a world where the serial wideband and the analog output wideband do not agree. Last time I did a trace I could see the two wideband traces follow each other, but one was a little leaner than the other. I plan on playing with voltage offsets and actually driving the thing to see how close they correlate. If they never correlate... then, well, maybe I'll never use either. Ideally I'd like to have the Analog wideband read ever so slightly leaner than the serial one, because the serial one is 'correct'. Tuning the car to be ever so slightly too-rich would be the aim. Not needing to have a laptop flying around in the footwell connected with cables is... an advantage. About the only one from the forced upgrade to MPVI3.
×
×
  • Create New...