fuel screw vs. shutdown temps

[IRoss]

The other day while doing an oil change I gave my fuel screw another half turn, which effectively bottomed it out, from the feel of it....along with this power came an extra 3-4 minutes of cooldown time to reach 300...its running noticably hotter in the lower (1800)rpm range than the upper(2400) rpm's. Now will un-adjusting the smoke screw (fuel under low boost, right?) help ireduce egt's while just cruising around at low rpm, allowing the it to cool down a little faster,? Could it have anything to do with the oil? (shell 15w40 Rimula, just switched fr/rotella)
thanx, ian

[flashgordon]

The other day while doing an oil change I gave my fuel screw another half turn, which effectively bottomed it out, from the feel of it....along with this power came an extra 3-4 minutes of cooldown time to reach 300...its running noticably hotter in the lower (1800)rpm range than the upper(2400) rpm's. Now will un-adjusting the smoke screw (fuel under low boost, right?) help ireduce egt's while just cruising around at low rpm, allowing the it to cool down a little faster,? Could it have anything to do with the oil? (shell 15w40 Rimula, just switched fr/rotella)
thanx, ian

The smoke screw is pretty much for idle and off idle(no boost) setting

putting more spring pressure.(star wheel, turn counter close wise.......I thing) on the fuel pin. would help

Did you gain smoke with the full fuel screw?

Flash.

[IRoss]

Just a little bit of black on spool-up(between shifts) but nothing major, I don't really get a lot of black smoke unless I'm lugging it....I maybe have 3 or 4 threads showing on the smoke screw..

[PToombs]

Flash I think you got it backwards a little. If the smoke screw is turned in, the starwheel won't affect it any. The screw will lower fuel on the bottom if you back it out. It overrides the spring at idle, pushes the cone down.
If you turn the starwheel down, it will fuel faster when boost comes on, up, slower.

[flashgordon]

Flash I think you got it backwards a little. If the smoke screw is turned in, the starwheel won't affect it any. The screw will lower fuel on the bottom if you back it out. It overrides the spring at idle, pushes the cone down.
If you turn the starwheel down, it will fuel faster when boost comes on, up, slower.

Ammmm, ya what PToombs said.
it been a while sence i had the hat off the inj

The more spring pressure that is applied to the pin/diaphragm the more boost it will require to rise the fuel pin......right?

and the screw on the top sets the fuel pin/diaphragm starting point.....Right, or am i way off base here.

Flash

[PToombs]

Yup, you got it. Spring pushes up, boost down. Screw pushes down. Down is more fuel, fast down, faster fuel!

[TWorline]

Whoa... slow down there Pete, your getting pretty technical on us.

[flashgordon]

Yup, you got it. Spring pushes up, boost down. Screw pushes down. Down is more fuel, fast down, faster fuel!

Cool,

Ya i was thing of slowing down my fuel at boost, to help with my toasty E.G.T. when towing.
But, winter helps a lot on that, and after i get my intercooler installed, I may want to, feed the fire some more.


Flash.

[PToombs]

Sorry Tim, I know you're from Ohio!

[TWorline]

Thats right, I just figured out what that double spiney thingy was!:colors:

[PToombs]

What, this?

[dpuckett]

I'd say tighten up your starwheel a few rounds. The longer shut down is exactly what Mom's was doing before we got her pump redone, and I forget what exactly was wrong with it...... I'll mull it over a while. Maybe gov return spring getting tired? What injectors do you have, and how old are they?

Daniel

[flashgordon]

What, this?

A proctologist that like his job, way to much!


flash.

[IRoss]

Ive got the PDR190's daniel, and my timings been advanced as well....on an update, I finally got around to lowering my idle back down from the fuel screw adjustment, and that seemed to help a bit....if I've been on the highway cruising the egt's are fine (750 or so) and will come down fairly well, but its more when I've been cruising around at the lower boost levels (<12 psi or so) that they seem to stick and it takes longer to come back down...I'm pretty happy with the way my pump is adjusted right now, I hit about 30 psi with very little black smoke, so I might just end up turning the fuel screw back a bit, but I appreciate the input...
ian

[PToombs]

If you like the way the truck runs, try backing off the smoke screw first. It's easier to access, and I think you'll find your temps will go down. If you don't like the results, it's easier to turn back up too.