Made some fuel pump changes...

[WayneIlfrey]

Well, last night I started to tinker with some of the fuel pump settings that I have read about here on the list and in other places.

I moved the diaphragm 1/4 turn clockwise, and then turned the star wheel 1/4 turn clockwise. I experience a rather nice power increase. She takes off with alot more spirit now fer sher. I may even go a little farther on both and see what happens.



One question to your wrench gurus out there.



What can I do to improve my top speed (if anything) without spending cash on new injectors and turbines?

I read about the "Full Power Adjustment" but im not sure where the adjustment is for this, and is this the adjustment I want?



I want to do the injector and turbine mods eventually but cash flow is prohibitive right now. (SWMBO has put a moratorium on spending for toys!!!:{ )

 

[paccool]

Wayne, the best thing to do is to go to "readers Rigs", at the bottom there is a bar to click on. That is in alpabatical order. Find Bushwaker's album and click on it. In his album he has a section for the fuel pumps. In that section there are some great pictures that will show you where everthing is located and there are instructions for turning up the full load screwand engine RPM. That is what you need to do next.

 

[WayneIlfrey]

Perfect!!! Thanks Stan (and Bob) that is exactly what I needed to know. I was definitely looking at the wrong bolt last night. I'm glad I waited and asked. Also see the picts on the front break rotor stuff. I just bought 2 new front rotors. Both have been gouged out so bad that no one will turn them. Doing a complete front break rebuild this weekend (will also be installing new shocks while im at it).



One other question, is there any benefit to adjusting the Governor? I haven't read anything about that but I see it listed in Bob's picts as an adjustable item.

 

[paccool]

Make sure that when you do the brakes that you clean the slide areas for the calipers real good and use Caliper grease. I was having trouble with my brakes and it looked like the calipers were sticking a little on the slides. Did the above on mine and so far everything seems to be working OK.



Some of the guys have reported that the governer was kicking in around 2400 RPM. Increasing the RPM limit will give better top end. Be careful though to keep it below 3000 RPM. (a few guys have gone a little farther than that) You need to have a tach to see what is happening when you start turning the screws.



Hopefully someone that knows a little more about this will jump in here. Hey Bushwaker, how 'bout it?



Stan

 

[formula]

Wayne,

Turning the full power screw won't increase the governed rpm much if at all. The full power screw adjusts the limit of the amount of fuel that is injected while under load. To increase the max rpm of the engine, you need to back out the high idle screw. The actual effect this has, as far as performance is concerned, is that it increases the rpm at which the governor begins to cut back the fuel delivery (defuel). The defuel point lags behind the max no load speed by about 300rpm or so. If you up the high idle from the factory 2700 to 3000, you'll get full power delivery all the way to 2700 rpm instead of 2400. This will make the truck pull much harder on top end and improve driveability, especially on highway. I would not recommend playing with the full power screw unless you get a pyrometer. Increasing fueling with the factory turbine housing, air filter, and exhaust can lead to some toasty EGTs.



As far as the adjustments you have made so far to the pump.....

Turning the diaphragm clockwise changes the profile of the eccentric and makes it steeper. This will increase the rate at which fueling is increased with response to boost. Turning the starwheel clockwise reduces the boost level that is required to drive the eccentric downward. This means that fuel delivery rate will begin to increase at a lower boost level.



Cheers,

Sean

 

[WayneIlfrey]

Thanks Sean,

Now can you give me an estimate as to how much I can turn the high idle screw? My truck is an auto so no tach.

It is going to be stock set because my father bought the truck new and I know he never modified the fuel delivery.

Whatcha think, 1/4 turn and play with it or just turn it a whole turn.

Thanks for all the help.

 

[formula]

Wayne,

Each turn will give you 75-100 more rpm. Two turns should be just fine for you. I wouldn't go more until you get a tachometer. BTW, you'll need to back the screw out (towards the rear of truck) to increase the high idle. Read this thread for details and tricks for making the adjustment. https://www.turbodieselregister.com/forums/showthread.php?threadid=58462&highlight=2900



Sean