LB7: Tunning Assistance

[WisconsinHick1]

I have a built motor LB7 with 100% injectors with dual modified pumps. Now that it is colder I am starting to have an issue with my current tune I have built and worked on myself. I deleted the glow plugs and I think this is my issue. When I go to drive my truck with the motor not up to operating temp it misses and produces white smoke (raw fuel), but after its up to operating temp it runs fine. Also on a lower setting if its up to temp or not it seems to be missing. No signs of a bad HG but Im wondering if my pilot injection is set too high still as I have been pulling it back because of the fuel knock I was getting.

Anything else I should be looking into on the tune to help or will I need to put glow plugs back in to have it drivable in the winter? Do I need to keep pulling the pilot injection down so I'm not loading the cylinder up with fuel?

 

[sweetdiesel]

Its probably going to knock more as you pull pilot.
you can adjust timing ECT to get the temps up at a lower ECT

 

[sweetdiesel]

You could also try adding some pressure

 

[DIESELMAFIAPER.LB7]

Why are people deleting glow plugs?

 

[sweetdiesel]

Why are people deleting glow plugs?

It affects spray pattern and possibility of a tip breaking on a race motor can cause damage........Also you can get rid of a bunch of electrical crap

 

[DIESELMAFIAPER.LB7]

on a dedicated race truck sure but on a dd ? I see no reason to it gets way to cold to start without them here, have people really had that many glow plug tips break off?

As for the op id put pilot back up and add pressure like simon said to try

 

[x MadMAX DIESEL]

You do have big injectors too, might just be the nature of the beast. Mine will kinda do that too with 60 overs. Maybe you can correct it with an efilive tune. I'm not sure. But injectors would be the cause.

 

[WisconsinHick1]

Its probably going to knock more as you pull pilot.
you can adjust timing ECT to get the temps up at a lower ECT

Maybe I'll try to put more pilot back in up top but it was knocking real bad were it was originally. Alsi try adding timing and pressure one thing at a time to help. I didn't think about adding pressure but it makes since that helps atomize the fuel better.

 

[sweetdiesel]

Maybe I'll try to put more pilot back in up top but it was knocking real bad were it was originally. Alsi try adding timing and pressure one thing at a time to help. I didn't think about adding pressure but it makes since that helps atomize the fuel better.

Use the dvt controlls to increase the pressure it can give you a idea of where you need to be

and I would try lowering timing VS raising that will get a lil more heat.

 

[WisconsinHick1]

I will give it a try thank you very much sir.

 

[S Phinney]

I will give it a try thank you very much sir.

Are you still idling at stock values? You probably need to be in the mid 40 mpa at idle with those injectors anyway. The lower compression is where the not atomized fuel is coming from though. It is doubtful that you will eliminate that problem without upping compression.

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[S Phinney]

One other way to help the problem would be to use the block heater

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[DuramaxPowered]

On my LMM, I was able to clear up a decent amount of the cold idle smoke/haze by upping the rail pressure to 60MPA.

 

[Killerbee]

Of course it is the deleted glow plugs causing the cold smoke problem. I personally don't see how that can be practical. How will you start it in December, unless you have some 200 degree air to put in the airbox?

agree with most thoughts. You will have to increase idle pressure to around 45mPa or more, and you may also have some luck playing with timing. I would leave pilot at stock values (or reduce) while you play. If you have increased pilot qty at factory pressure, it is probably drowning your piston in fuel and keeping the cylinder too cold with evaporative cooling. White Cold smoke is unignited fuel charge.

If compression is low, and on a cold day, things worsten. Simon had a great idea, play with pressure using DVT controls to fine tune. That gave me an idea for another challenge I have that is just a PIA with multiple flash iteration.

 

[WisconsinHick1]

On my LMM, I was able to clear up a decent amount of the cold idle smoke/haze by upping the rail pressure to 60MPA.

Were you maintaining stock pilot injection?

With my pilot injection at stock it knocks bad as I increase throttle.