Interesting... It could very well be the pump. My original pump was leaking and wouldn't keep the car running on anything but purge. (Lift pump failure). I ordered a reseal kit from Oregon Fuel Injection. However in the meantime, while waiting for that kit to arrive, I came to think about the pump I saved of the old motor I replaced. It had been lying in the trunk of a car on a meadow, summer and winter, possibly empty on fuel for approx. 2,5 years. Sure enough it fired right up, but has been shaky at the mentioned rpms since. I ran the car for too little time with the old pump, to know if the problem was there already. It actually came with a bad pump, as I ordered the whole motor from Denmark, but I was too late to diagnose the pump, for the warranty to cover it... I know it's not the static timing, as some of you mention, as I've tried both .9x and .75 (two different booklet specs) and the problem remains constant.
Valve adjustment is something I've suspected too, along with injectors. Valve clearances are the next thing I will check, although I still haven't removed the valve cover to check if it's hydraulic or shimmed.
Compression "ringwise" however, is not something I suspect, as the motor had a leakdown test done to it, before I bought it and they said it was very good for an engine of its age, and gave me a number of 18. I don't remember what it stood for. I bought the engine almost four years ago, but I probably haven't put more than 1000 kilometres (600 miles) on it. Also it fires right up within the wink of an eye, when cold. Very cold too. And there's NO blowby whatsoever, as long as the oil pressure is up. I have a problem with the oil pressure dropping down to the red field of the gauge at idle speed, when the engine has been running with high to moderate boost for a while after being warmed up. (I know the pressure can be altered by the tension a spring) Anyway. When this occurs I have a tiny amount of blowby. Nothing close to a concern though. It could actually be oil vapor, as the oil is being warmed up so much by the stress. Also what I don't like about the setup, is that the turbo does not have water lines for primary cooling, leaving the oil with the entire job.
Best Regards Ragnar.
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