Looking for advise on pilot injection

[longcummins]

Thanks again Les you are a great help on this forum.

[mpdtune]

Don't be afraid to play with it some. The CNG is acting as the new pilot injection, in theory. Made need more or less to allow it time to react in the cylinder.

[longcummins]

I now have about 20 miles on it with the timing adjusted and now I get no codes so I am good for now. Thanks for the input guys it's appreciated.

[longcummins]

Actually with the pilot turned off at 1400 rpm and above, the CNG can't burn until the start of the main injection. Their is no spark for it to do so until primary injection.

[computerjlt]

interesting, how much CNG is used. is it a set amount or does it vary by rpm/load?

I've seen natural gas used on big industrial diesels to offset using as much diesel or fuel oil (i was reading a lot of these papers to learn more about diesel combustion and cylinder pressures and how everythign ties together). i've never seen it used in a passenger vehicles except for CNG and LPG conversions that were popular years back.

[longcummins]

The best advice I can give you computerjlt is to go to cummins forum. Go to alternative fuels and lubricants section. Look up cng in a diesel to start with and a couple others there in that section and read a couple pages it should answer some of you questions.

[mpdtune]

You might try using a much smaller pilot injection to ignite the CNG. That way it would be burning before the main event, should give more complete combustion of the diesel.

[longcummins]

I have been running the stock setting on pilot until last weekend. I now see a lose in mileage running with out pilot injection. The rattle from the injectors was driving me nuts also without pilot. Now I am back to running the pilot injection set to factory spec.