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Optimizing Fuel Delivery for clean combustion with Emissions Installed

Practical Diesel Tuning

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Discussion and questions related to the course Practical Diesel Tuning

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In the module where you are confirming the tune on the road you noticed that the truck was smoking and adjusted the fuel quantity to get a cleaner output. What about the newer trucks with DPF and DEF installed, how do i know that the truck is smoking since most of the sooth/smoke will be held by the DPF before it goes out into the atmosphere? My concern is that i am invisible there and produce to much sooth and therefore clogging the DPP. Can i refer to the pressure sensors and such to determine if i am producing to much smoke/sooth?


Uh, it isn't too clear what you're asking - is it in reference to an over-fuelling situation where one would normally see a sooty exhaust? I would expect this to be caught by the filter with the most significant thing being more frequent burn off cycles. But it isn't my field and I may be mistaken.

Depending on the vehicle, it should have a lambda (or more than one) sensor for the ECU, and there are several products that should allow you to read the value(s), and also the EGT which is also something to be concerned about.

Hello Gord, there are engines that have a DPF installed but there is no lamda, pressure or sooth sensor installed. This was made on cars that had to comply with emissions after they came on the market. As an example the 1.9 TDIs from Volkswagen. How can i make sure i dont clog up the DPF if i go very aggressive with the SOI and such?

The only way to get that kind of real-time feedback is to use a WB02 sensor or PM sensor in the exhaust stream before the DPF. I usually do this an create a histogram of actual Lambda to verify against the lambda limit table. If you do this on a stock vehicle you can get a pretty good feel for what Lambda values are safe. Going richer much richer than the factory you'll quickly find the threshold rich lambda which causes soot and results in the DPF soot counter rising sharply.

Short answer, you'll need a WB02 if you have a DPF equipped vehicle and want real time data.


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