Ok, just rigged up a gauge, I used my Sun Electric pressure gauge from my gas engine diagnostic/tune up kit because I know it's very accurate, and at 4 inch diameter, it's nice and easy to read while driving. I tee'd it into the small pipe that runs from the inlet manifold to the top of the pump. Not much happens free reving in neutral until the revs get up high but obviously it's not under load so I wouldn't expect much boost at lower revs. Once driving however (it's auto) the boost shoots up as soon as you touch the throttle, even the slightest pressure on the throttle gives an instantainous increase in pressure which rises very smoothly and rapidly. Being auto I cant "hold it" in gear but on half throttle in 2nd I can easily get minimum 10 psi boost before 3,000rpm, in fact it's probably pushing a good bit over 10 psi, my gauge only reads to 10 psi and the pressure builds up so quick you can actually hear the needle "dink" as it hits the stop. On a kick down to 2nd at 25 mph, it goes from about 1.4 psi to 10 psi in 0.9 of a second (using a calibrated digital timer) Climbing a steep hill in second I can easily get 10 psi at around 2,700 rpm on lightish throttle so It looks like the turbo is working just fine. Your probably spot on regarding the fuel pin/star wheel aspect as the power really comes on with a bang above 3,100 rpm, and I would also suspect it's running weak/lean anyway (if their the right terms to use for a diesel) as apart from a very slight puff of light greyish smoke when starting there is no smoke whatsoever from the exhaust even at full power, the tailpipe itself is exceptionally clean for a diesel (the exhaust is about 5 years old) no sooty or oily deposits at all, it's more like a gas engine exhaust. At night you can normally see smoke showing up in the headlights of the car behind, with mine there's no smoke at all showing up, all you can see is what I would call a "heat haze" effect, a kind of visual shimmering, but certainly no smoke, so it looks like the engine could easily handle some more fuel.
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