Yanmar Turbo Pressure

[Travelmate]

Have a Yanmar 4JH4-TE fitted to a friends cat. Lack of performance from one engine points to lack of turbo boost or anti-smoke device malfunctioning. Need to test turbo boost but the workshop manual gives no data. Can't be sure the good engine is correct so cannot rely on readings from that..

Need either a graph or data to determine the boost pressure under varying conditions.

Thanks
Tony

 

[Tony Cross]

I'm not sure this is going to help, but I have a 4JH2-TE and I have the service manual for it too. In the turbo section in there all it gives is the range of boost pressures for the various engine models in the 4JH2 range. For the TE is says 750 ~ 900 mmHg (29.53 ~ 35.43 inHg). The exhaust gas pressure for the 4JH2-TE is 835 mmHg (32.87 inHg). It also says that this is with "Max. rating output and back pressure 300 mmAq (11.81 in Aq)". What's Aq?

I had my turbo serviced a couple of years ago because of very smoky exhaust, the place that did it said all the seals were shot.

 

[Travelmate]

It also says that this is with "Max. rating output and back pressure 300 mmAq (11.81 in Aq)". What's Aq?

That would be 300mm of water usually measured with a slack tube manometer where the measurement is taken between the difference in the levels of the water in the tube.

 

[Tony Cross]

It also says that this is with "Max. rating output and back pressure 300 mmAq (11.81 in Aq)". What's Aq?

That would be 300mm of water usually measured with a slack tube manometer where the measurement is taken between the difference in the levels of the water in the tube.

Oh. Thanks for that!