Hi all, my first post
I came upon this site during a search for NADS help. I think this is the best talk through and Pics I came across. Its what I used for reference on my fit out.
Over the last few months I have been fitting the bits required. I have had the boost gauge and Catch Can on for a while as well as a blocked EGR for a few years with the VNT screw backed off slightly to compensate. I had been having limp mode issues. An EGT gauge is mounted but not fitted yet, waiting for a new exhaust.
On a recent desert trip the maximum boost achieved was 12psi, on that trip I developed a leak in my long range main tank. While it was down for repairs I fitted the Dawes Valve and Needle Valve, not ideal and as you recommend testing at each stage.
To the reason for my post.
I have next to no boost pressure. I am sure the plumbing is all correct, checked so many times I can see the layout in my sleep.
Following the instructions, closing the needle valve [ no boost ] open slightly and actuator arm starts to move, open more and the arm moves more. So as instructions state when arm moves turn back till it rests on the stop, in my situation that is the closed position.
As stated, if less than 15psi adjust Dawes Valve by unscrewing [ backing off ] did this without result. Next stretch spring a tad, If I stretch it any more it will be a piece of wire. Really I have stretched it more that should be needed. Still no boost.
After completing the NADS installation my gauge was showing a slight vacuum.
After setting the needle valve, 0 boost
After stretching the Dawes spring and it backed right off it is showing 3psi at 3000rpm
I have checked for leaks, hoses fittings and inter-cooler with soapy water, Vacuum seems sufficient, VNT arm seems to move freely,
Something is seriously wrong and I have run out of ideas at the moment.
I was going to delete this post as I may have an idea to check tomorrow
My thought is, if as instructions say, that if 15psi cant be achieved unscrew the Dawes valve 1/4 turn at a time, if still not reaching 15psi then stretch the spring a tad.
Unscrewing relaxes spring pressure on the valve , so why would you stretch the spring, it will only increase that pressure,
If anyone can clarify this or has and info it would be great.
Thanks
John
