AQAD40 no power/Turbo boost

Blackpearl25

Recruit
Joined
Mar 12, 2012
Messages
2
Hi all, My first time here!
I have a Novacraft 25 sedan with a AQAD40 turbo diesel that I have been restoring over the last 4 years.
The motor runs fine and free revs to about 4000 rpm, but on the water it lacks power and will only spin a 14 inch prop @ 3600rpm and 17 knots.
(I think the previous owner was using a 17 inch prop and would cruise at 20 knots!). I found a plate on the back of the intercooler that was leaking air and thought that my problem was solved. I put a boost gauge on the engine and it has no boost at all at 4000 rpm. There is no preasure ( only vacuum) if I take the gauge off and just feel the hose.
The turbo is spinning fine , there is no blockages in the exhuast, the in take has no blockages.
Do you think that under load now that the leak is fixed that there should be boost? or should there be boost at free rev? ( I know my Hilux diesel has 3 psi with no load).
Any help would be great, Thanks
 

Blackpearl25

Recruit
Joined
Mar 12, 2012
Messages
2
Re: AQAD40 no power/Turbo boost

Thanks Don S
That Manual will be a great help, I think my boat might be OK, I just need to find time to put her in the water and test it under load like the Manual states.
Thanks again
 

MCL

Petty Officer 2nd Class
Joined
Feb 13, 2010
Messages
109
Re: AQAD40 no power/Turbo boost

Dont remember if the 40 has a wastegate but if it does it could be that it is open for some reason,perhaps a broken spring etc.You wont see much boost revving the engine without no load.
 
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