My Toyota Landcruiser BJ44 has a Toyota 2B Diesel with a turbo setup.. the Turbo is a Mitsubishi TC05.. a small non-waste-gated turbo thats makes a 5.5-6psi boost max.
All turbo diesels are equipped with boost compensators that increase the fuel deliver from injection pump as the turbo builds up boost.. the toyota 2B uses a vacumm driven inline pump and doesnt have any sort of boost compensation.. as a result overall fuel delivery is kept a tad higher resulting in black smoke in off boost conditions.
After installing a boost and EGT gauge.. i planned to mess up pump fueling directly 🙂 Based on Yotahead@ih8mud and traveller@ihmud experiences with using a Merc Benz 240D’s governor spring.. I asked my dear friend Nashit to get one from the Benz land.. the spring arrived this month.
With stock spring.. the max EGT was around 550C.. with offcourse thick clouds of black smoke. We mark this as the starting point.
Took off the top cover to get the spring out
Merc Spring vs Toyota stock.. Merc one is longer and wound with a thinner wire
The spring is inside the top housing where this pipe files.. 4 screws take the cover off.. be careful you need not remove the diaphragm for this.. remember to clean the cover and place a little grease on the edges to ensure sealing.
Merc Spring vs Stock Spring with cover
Everything installed back.. started up fine.. noticeably less smoke from idle upto 3000rpm.. there was a little erratic idle just like a Hino truck 😛 Ignoring that for now
Took the old cruiser on the road.. Immediate result was better throttle response with lesser smoke… pulled better.. turbo spooled to boost earlier and was holding boost well… a few quick runs up and down the airport road.. turned the fuel down 1/4 turn.. and it was running better with much less smoke.. the peak EGT was still within 550C range.. I still need a longer trip to see the effects on mileage.. Stay tuned to updates on this.. So far im happy with the upgrade and now I really want to upgrade the turbo to get at least 10psi boost 😀
Where did I learn this stuff.. some very useful info at ih8mud: