13BT: fuel amount/tune (1 Viewer)

[jblueridge]

Since I got my injectors cleaned, my 13BT is getting too much fuel. Smoke and carbonized exhaust interior.
I have done some searching and found good information on the ways to reduce the amount of fuel injected: max fuel screw and boost compensator adjustment.
People wrote that it is a trial and error thing: make changes to the fuel input and see what happens.

Any targets I should be aiming for, like a certain exhaust gas temp?
Thanks.

 

[dare]

With the EGT preturbo I'd go for max 750c sustained. Still you can be smokey with less than that, mine certainly is.

Are you sure it's getting enough boost?

 

[roscoFJ73]

Since I got my injectors cleaned,

Cleaned or rebuilt? Im not sure about the B engines, but on other types of newer diesels they have a teflon coating on the injectors tips and cleaning or even wear and tear damages them. This might be the cause of the smoke. But try turning the fuel down and see what happens.

 

[jblueridge]

I have a boost controller and the boost gauge shows 12psi max...5-8psi on highway.
Rebuilt injectors.
EGT seems to max out at 700C. Sensor is pre turbo.

 

[Nz Nath]

700c preturbo is about right by most opinions, if anything you could go a touch more fuel. Sounds like you need to cut the low/no boost fueling down with the boost compensator.

Are there any drawbacks to over fueling off boost? Other than emissions and visible smoke? My 13bt powered truck plumes out black smoke if you get it in 3rd gear at very low revs on a steep hill. But in normal driving the holset turbo spools so well this just results in a moderate puff of black smoke when you're pulling away and changing to 2nd and 3rd. I'm not in any rush to dial it back.

 

[jblueridge]

Fuel economy has suffered, so that's one negative for over-fueling.
Carbon build up is another.

So boost compensator adjustment screw limits amount of fuel when not boosting?

 

[Nz Nath]

Yup. Turning it half a turn out would probably be a good start. And the guide bushing adjusts the preload on the spring the diaphragm pushes against. There is a thread that details the adjustments.

 

[jblueridge]

I got at the Max Fuel Screw and backed it out about 270 degrees.
Black smoke is much reduced. Notable loss of power however.
I'll drive it this way for a while.

 

[jblueridge]

Increased fuel using Max Fuel screw. Now its backed out about 135 degrees from original over-fueling position.
Boost controller provides max boost of 16 psi. Ran at about 12 psi up Blue Ridge mountains.
EGT topped out at 1200F.
Seem to be getting 23+ mpg.