Pilot Tuning?

[2006Cummins]

Was wondering if there are any advantages of playing with the pilot injection at all. I have 50hp injectors, so I was thinking about reducing the pilot a little to compensate for the increased fuel, and help reduce smoke. What do you guys think?

Mike

[2007 5.9]

Yep...it will help.

Start with small changes

~Les

[2006Cummins]

Ok. Should I start by subtracting a small percentage (5%?) thru-out the entire pilot pulse table? My injectors are roughly 18% larger than stock - so could subtract up to 18% before injection less than stock? Thanks.

Mike

[2007 5.9]

Start with smoothing of the tables...rid the tables of peaks and valleys...get it more uniform and smooth.

See how that feels...then begin to take away %...you can start at 5% and go from there.

~Les

[2006Cummins]

Roger that.

Mike

[2006Cummins]

I smoothed out the pilot pulse graph a little and then subtracted 5%, 10%, and 15%. It runs fine, but anything over 5% will give me some white smoke if I bring the rpm's up to 2k and let off (while parked). Didn't notice much difference otherwise.

Mike

[2007 5.9]

If you take out too much in the low rpm areas, it disables pilot in those areas and youll get white smoke.

~Les

[AdamRRT]

Hrmm I've got a single event tune that I gives me no white smoke.

[2007 5.9]

Hrmm I've got a single event tune that I gives me no white smoke.

Did you compensate main timing??

~Les

[AdamRRT]

OH is that what you were saying? My bad. I thought you meant ANY single event tune. I'll STFU now. :(

[2007 5.9]

I was explaining that if you take pilot away without compensating for it..you'll get white smoke.

You can do it either by removing pilot completely or take too much out. Less than 1.5-2mm3 can disable it.

~Les

[AdamRRT]

Yeah I missed that. I thought you meant if you take it out at all. My apology for chiming in.

[AdamRRT]

Crap! This was the coldest morning for me to start the truck with the single even tune on. 48* F. I got white smoke for almost a full minute on startup.

I'll end up keeping some small pilot on startup and at parking lot speeds (so it doesn't sound like garbage), and fade into a single event.

[olboyowl]

did the same for me a few weeks ago. have pilot back on now. gonna start pullin it after 1500 rpm and see how it runs. got the next three days off for hunting and will play with this in between. will post results

[olboyowl]

so, monday i tried phasing pilot out after 1500rpm to have it completely shut off by 1700. truck didnt like it. as soon as it hit 1600 (and got below 3mm3) it started throwing white smoke and shaking. temps were in the 40's and truck wasnt warmed up yet. i'll play with it some more when i get a chance

[AdamRRT]

Dang son you revving past 1600 cold? Sounds more like you didn't compensate timing after removing it, to me. But I could be SO wrong.

[olboyowl]

no, not revving at 1600 at idle cold. gave it about 2-3 minutes and took it for a drive. my bad. forgot to type that. also, timing was compensated for.

[2007 5.9]

Sounds like not quite enough timing added...what is your values for timing once pilot is removed??

[AdamRRT]

That's what I think too. That's what I was trying to get at, but with my limited experience I need guys like you to chime in to verify.

[olboyowl]

sorry for the delay. got to trackin a deer last night and didn't have time. don't have my laptop on hand but from memory, i would say between 25-30* with the bias from 1500rpm and up. again, won't be able to verify till tomorrow and might be wrong.

[MQ105]

Les, are you saying that if less than 1.5-2mm3 is commanded as pilot, the pilot event may not happen at all?



I was explaining that if you take pilot away without compensating for it..you'll get white smoke.

You can do it either by removing pilot completely or take too much out. Less than 1.5-2mm3 can disable it.

~Les

[2007 5.9]

Sorry i put the wrong values in there.... anything less than 1.0-.5 has killed pilot on both my truck and sled puller.

Sorry for the misleading info.

~Les

[MQ105]

The pilot doesn't happen at all if commanded volume is less than that amount?

[2007 5.9]

The pilot doesn't happen at all if commanded volume is less than that amount?

This has been my experience

~Les

[MQ105]

That's good to know.