Symptoms:
Engine starts easy on cold starts but will idle roughly (almost dying) after start up with lots of blue smoke coming out of the exhaust. It will idle and run smoother after a couple of minutes but will always shift irregularly on the drive to work. It had very bad fuel consumption (approximately 430 kms on about 65 liters) but I drive 900 ft up everyday. There were signs of black smoke when accelerating to speed up. The very annoying issue aside from the fuel consumption was its shifting pattern. The transmission doesn't know or can't really figure out which gear to shift at different rpms.
Diagnostics:
Engine and transmission computer are not on the same frequency...meaning the engine is not delivering the correct power based on the throttle position sensor and kickdown cable adjustments. We suspect a bit of fuel dillution (explains the blue smoke) and very rich condition (black smoke on acceleration) that the engine generally runs on.
Solution:
Well, the injectors were all cleaned up, its pressure settings corrected and spray patterns were met. We adjusted the throttle position settings and kick down cable adjustment as well. Having done that, we tested the L400 again and overall conditions improved but not satisfactory from what it should be. Only one thing remains that will contribute these symptoms as well....the injection pump. We removed it and did the overhaul and reseal. These were our findings on the injection pump....thru time, the front shaft oil seal hardens up and allows a certain amount of oil to get inside the pump. The mechanical fuel pump is inside the IP and sucks in the oil thru this seal as the whole front of the IP is exposed to oil along the timing chain/gear drives. This explains the blue smoke in the mornings as the oil slowly gets in overnight. As the oil affects the internal parts of the pump as well, the 'usual' governor sleeve gets sticky and thus affects its functions and will not respond to the fuel requirements it needs to deliver at different load conditions. So, after the IP overhaul, my L400 drives and shifts perfect! Fuel consumption improved to about 550kms on 65 liters. No smoke. Starts easy and smoothly even on cold days.
Difference between the L300 and L400 IP....they're similar except for the labor time to do the removal and install for L400. It takes about 2 hrs more than the L300.
Cheers
, and as for smoking issues have had my Deli a long time and EGR is the first thing to look at before getting carried away with injector issues as its only 2 bolts and a plate..10 min job and it has nothing to do with tuned but a Japanese vehicle emission requirement we don't need and is usually the first culprit with an imported Delica.The idea is the easiest priority order then the more invasive or expensive items
laugh here)