DJetronic Limitations Options

[Teknon]

It's probably been said before many times. So if there is a thread you can lead me too all well and good. (IMG:style_emoticons/default/confused24.gif)

I am having a 2270 built and was told the DJet FI will not be enough to handle the fuel requirement of this engine. I am not interested in a mechanical carburetor at all. And have no room for that discussion. (IMG:style_emoticons/default/dead horse.gif)

Why can’t the DJet keep up? Can it be tweaked or larger injectors installed? (IMG:style_emoticons/default/WTF.gif)

“Chicken Little” type members need not answer, as I don’t need someone’s emotional opinion. What I would like is a down to earth technical understanding. (IMG:style_emoticons/default/yappin.gif)

I am surprised no one made a daughter board to augment the existing ECU to test oxygen or whatever would be pertinent.


Thanks for your time and experience.

Joe D2

[lapuwali]

It's not just "D-Jet" per se, but a lot of things. The 2.0 plenum and throttle body are sized for a 2.0, so if you're running nearly 30% more displacement, you're going to get about 30% more airflow demand, and the air intake will likely be too small to handle that.

The D-Jet MPS can be adjusted to handle a different fuel curve, but it's a fiddely process that requires a lot of expert knowledge very few people have. Bleyseng seems to have figured out how to do it. The stock injectors are actually quite large, so you could PROBABLY get the D-Jet ECU to keep them open long enough to flow the required amount of fuel, up to around 180hp or so.

Most people who are doing what you want to do will replace the D-Jet MPS and ECU with an aftermarket PEFI ECU, which can be programmed w/o any hard-to-find expertise. It also eliminates the MPS, which will eventually be impossible to rebuild. Dave Hunt has managed to make the stock 2.0 plenum with a bored-out throttle body work on a 2270, but I think he's intending to expand the size of the plenum, too. He's using Megasquirt as his ECU. You can also go to individual throttle bodies (TWM, Jenvey, et al), and get the looks, throttle response, and sound of Webers while still having fuel injection.