Sir, Ive read your post from day 1 till this last post you wrote. Maybe you can help me with my problem. We have a 98' L300 diesel versa van 4D56 NA engine. Well maintained at 144K+ mileage. I had the the IP calibrated and Nozzle tip replaced back in '08 (mileage before was 110K+) since it was starting to smoke and having poor fuel consumption. Since the calibration, I noticed that the power was not restored that much and its pick up was mediocre during acceleration, changing gear & during uphill was not satisfying. The feeling was like the engine is "sakal". Had it brought back to the calibration center several times where timing was adjusted, valve clearance to specs, and filters changed to OEM but still power is not enough. Compression is still good. Ive driven several high mileage toyota hiace diesels and I can say they have way more power than the L300 and they dont smoke that much either. I've lived with this burden for a few years until early this month I can't take its poor fuel consumption anymore (around 1 liter: 5-6km) so I had the injection pump re opened (at the same calibration center but with a different "veteran" technician. I watched how he cleaned the pieces one at a time and the only piece we replaced was the fuel feed pump sub assembly since it was the only one showing signs of wear along with the oil seal and the gaskets. Other parts inside the injection pump were replaced last 2008 and was noted to be ok. The IP was then calibrated with a BOSCH calibration machine at "full load" and other adjustments set to specs. Does this workshop have the Bosch/Zexel calibration data for your specific pump part number?

The Nozzle tip (ZEXEL) was still ok and calibrated to specs around (150-160 pressure). Injection pump-to-engine timing was followed (at "0" alignment marks). A dial indicator tool is required when timing the pump to the engine.

Once installed, I noticed the engine to run smoother though a little bit with a higher idle. Acceleration was much acceptable this time, the only thing I noticed is that It smokes a little more when changing to higher gears (esp from 2nd to 3rd gear). The diesel workshop probably adjusted your IP to deliver more fuel to give you more power.

My filters are relatively new, (around 7,000km used since I bought them). The fuel filter is ViC while the air filter is OEM (made in the Philippines-MItsubishi ). I had the air filter cleaned with compressed air. I had my exhaust pipes hosed off to remove the accumulated particulates. The only thing I havent done is to adjust the valve clearance. Then check your valve clearances and adjust if necessary.

It still smokes. What else seems to be the problem that needs to be addressed? I suspect the material of the OEM air filter (made in RP) is not that good compared to the old stocks that are made in JApan, hence, not permitting enough ram air? Do I have to replace my filters? Temporarily remove your air filter to check for any improvement in power.

I live in baguio by the way, sir. Baguio has very lean air due to its high elevation. It is normal to experience some loss of power because your engine is naturally aspirated. Turbocharged engines are more suitable for lean air/high elevation sites like Baguio.

cheers and kind regards, sir Thank you.....