PDA

View Full Version : why is my Boost fluttering (have ecutalk data)



RaynMan
27th December 2012, 07:27 PM
G'day

I have an 05 GU ZD30 with Dawes Valve and Needle Valve. To keep a long story short I got my vehicle back from Nissan and it was in limp mode. While I was trying to diagnose I played around with the dawes valve and have had trouble with the boost ever since. The dawes valve (already on the Patrol when I purchased it) was set to 15psi max.

Anyway I found the limp mode problem, Nissan took the intercooler off and pinched a vacuum hose when re-installing. After I fixed that the boost was out of wack since I had played with the dawes. I have adjusted the dawes approx 10 times and I think I got it pretty close to where it used to be. I disconnected the battery for 1 hour and then drove it for 10 mins, then I decided to log the data with my ecutalk.

Just by looking at the boost gauge I notice when I accelerate moderate to heavily the boost hits 15psi, jumps back to 10psi then kinda back and forth between those numbers for a bit. I have never noticed it flutter like that before (maybe it did, but i didn't notice). I haven't adjusted the needle valve but when I was playing with the dawes I took it apart, stretched the spring by approx 30% and reinstalled.

I can't work out why my boost is fluttering, do I need to adjust the needle valve? and why does the ecutalk display the boost in really high numbers such as upto 29psi when my in-vehicle gauge says it goes up to 15psi?

here is the full LOG (http://www.roamoz.com/images/ecutalk27122012_0.csv)

Here is the boost, speed & RPM data

http://www.nissanpatrol.com.au/forums/images/imported/2012/12/66.jpg

http://www.nissanpatrol.com.au/forums/images/imported/2012/12/67.jpg

http://www.nissanpatrol.com.au/forums/images/imported/2012/12/68.jpg

boots
27th December 2012, 10:33 PM
Hi RaynMan . My GU was irratic like this when I first installed my guages .Hence the reason for fitting the dawes and needle valve combo to it , and plumbed it up so it did not go through the vacuum control solonoid / ECU . Is yours plumbed the same as mine or still stock ? or maybe nissan replumbed it wrong for whatever reason .

RaynMan
28th December 2012, 02:37 AM
Just added a new graph to my first post.

Thanks boots. I'll be honest, I have no idea how the stock setup is or your setup bypassing the vacuum control solenoid to be able to tell you. I'll do some searching online but if you could elaborate or provide a diagram I'd be most appreciated.

threedogs
28th December 2012, 08:09 AM
you should have the vacuum solenoid blocked off, its right next to air cleaner box near maf sensor

RaynMan
28th December 2012, 11:14 AM
ahh yep, I believe it is. I've always wondered why a hose was folded and cable tied. I have been learning sooo much about my patrol from this forum, thanks.

So any other ideas?

http://www.nissanpatrol.com.au/forums/images/imported/2012/12/70.jpg

RaynMan
28th December 2012, 10:59 PM
Mine is setup the same as this diagram, except after the dawes valve, instead of teeing off to the boostgauge/turbo mine tee's off to the boostgauge/boostsensor in the side of the intercooler.

http://www.chaz.yellowfoot.org/images/Boost%20Control.jpg

and this is a pic of mine.

http://www.nissanpatrol.com.au/forums/images/imported/2012/12/72.jpg

Is this okay?