Quote:Don't know about all small diesels, but the VW TDI's engine control module (ECM) has a built-in barometer. Fuel injection doesn't need adjusting, but I am pretty sure the EGR works differently at higher altitudes. And maybe the amount of turbo boost.
Its clear that the flow rate of the diesel fuel has to be reduced for the reduced air at 13,000 ft, but does anyone know whether Toyota diesels or other small diesels need to have the fuel inyection timing advanced also?
Quote:A normally aspirated diesel expects to draw in the same amount of air on every intake stroke in order to generate enough heat from compression to properly burn the fuel. They are throttled by varying the amount of fuel injected. At high altitudes there isn't as much mass to the intake charge so it simply cannot develop the compression pressures required to get a good burn. Advancing the timing a few degrees would help raise combustion pressures but don't get carried away with it. Higher static compression ratio would be a good thing but probably isn't practical. A turbo is a wonderful gadget at higher altitudes but they don't typically add a lot at idle. Joe
no, these engines produce a lot of soot at idle. I'm looking for a solution for 6 of them (min) that are frecuently generating over 12% soot in 2000 miles, increasing viscosity to >100 cSt at 100C. My 3.0 Turbo 4Runner compensates pretty well, but the non-turbo engines need some adjusting.