DB2 Tech

[david85]

I've probably messed with every setting on my injector pump over the years, but I'm trying to remember which settings affect what in terms of performance.

I remember a couple of years ago I messed with an adjustment nut that is exposed when you remove the top housing cover. I think this affects the fuel delivery relating to RPM range, but I'm not sure (AKA governor adjustment).

Can some one tell me what this does and if there a way that I could be able to set this back to roughly stock position? I'm wondering if this could be why my high end boost and fuel flow seems to be choked.

 

[Agnem]

I believe that is called the Min/Max govenor setting, and seems to chiefly affect the idle setting and Max throttle setting. I fooled with it while developing the Moose Pump and often wished I hadn't.

 

[david85]

I believe that is called the Min/Max govenor setting, and seems to chiefly affect the idle setting and Max throttle setting. I fooled with it while developing the Moose Pump and often wished I hadn't.

I think you are right. Do you remember which direction has what affect? (Which way will increace maximum or reduce). I guess tightening the nut against the spring would increase the governor cutoff RPM, right?

I should have never messed with it......

 

[tractorman86]

i would think actuating the throttle with the cover off would tell you wich way you want it to go. IIRC full throttle is back, so if you want more Rs then move the action towards the back, if you want less Rs move it forward

 

[redneckaggie]

I was told by some idiot when i first got this truck that that setting was timing and knowing nothing at the time i messed with it i agree with david85 luckily i was smart enough to count revolutions and now it is back where it was stock i moved it all over the place trying to get it right and it seems like the more i moved it the more jacked up everything got

 

[david85]

Yeah, I think I was trying to get better fuel economy or something. Don't really remember too well what I was thinking.

I THINK....it affected throttle response relative to throttle position. So at one setting I could get full power without flooring it all the way. Then when I did go all the way to the floor, power backed off slightly.

As I said, I should have left well enough alone.

 

[69dieselfreak]

david85
what other adjustments did you do to your pump to get a little more peformance
besides the typical fuel screw
thanks

 

[david85]

david85
what other adjustments did you do to your pump to get a little more peformance
besides the typical fuel screw
thanks

I also adjusted the advance/retard timing lever on the side of the pump to the point of as much advance as possible without making smoke (the more the lever pushes in, the more RETARDED the dynamic timing becomes). I did see slight gains by fiddling with that, but the governor adjustment got me nothing and could even be costing me now.

It was while messing with the dynamic timing that I realized there was no real gain in advancing the timing. All it did for me was make more smoke at the top end.

If you feel like changing settings like timing, make sure you take very good and acurate notes so you can still put it back to where you started if things work as intended.

 

[69dieselfreak]

I also adjusted the advance/retard timing lever on the side of the pump to the point of as much advance as possible without making smoke (the more the lever pushes in, the more RETARDED the dynamic timing becomes). I did see slight gains by fiddling with that, but the governor adjustment got me nothing and could even be costing me now.

It was while messing with the dynamic timing that I realized there was no real gain in advancing the timing. All it did for me was make more smoke at the top end.

If you feel like changing settings like timing, make sure you take very good and acurate notes so you can still put it back to where you started if things work as intended.

how did you do that
thanks

 

[david85]

I have to remove the lever for each adjustment. The lever is held in place by a pivot pin, the pin is held in place by a C clip on both ends. Remove one of those clips and the pin can slide out. Once the arm is out of the truck you can make the adjustment to the bolt at the bottom end (tightening retards, loosening advances the dynamic timing).

The C clip is spring loaded, so it will try to jump off and is easy to lose so be careful when you remove it.

 

[69dieselfreak]

I have to remove the lever for each adjustment. The lever is held in place by a pivot pin, the pin is held in place by a C clip on both ends. Remove one of those clips and the pin can slide out. Once the arm is out of the truck you can make the adjustment to the bolt at the bottom end (tightening retards, loosening advances the dynamic timing).

The C clip is spring loaded, so it will try to jump off and is easy to lose so be careful when you remove it.

just to be shure thats the lever (looking at the engine from the front of the vehical) thats on the right side drivers side correct
is the adj on the lever or is it on the pump thanks for walking me through this i dont want to screw anything up

 

[david85]

The lever is on the driver's side of the injector pump and is oriented vertically. When you work the throttle linkage by hand, the lever will swing in at the bottom as you increace the throttle setting.

The adjuster screw is machine tapped into the bottom of the lever itself and is also a torx head. The stem protrudes through the lever (pointing toward the injector pump) and then the bottom end of the screw is what pushes against the timing plunger at the bottom of the injector pump.

Do not attempt to start or run the engine with this part out or fuel pressure will force the timing plunger out of the bottom of the injector pump and make a big mess of fuel.

 

[69dieselfreak]

thanks david85 im shure im going to be asking more questions later
thanks a bunch
i want to advance for more power right just to be positive

 

[david85]

If you want to advance the timing, then you will be backing the screw off slightly. I would go in 1/4 turn increments as its nearly as sensitive as the fuel pressure screw.

If it gets really loud and clattery at full power, then you need to back it off. Smoke at the top end of the throttle range that does not go away with higher RPM or boost is a smaller indication that you might be too advanced.

Just please don't go nuts with the timing, OK? Too much will give everything from the pistons down to the main bearings a real hammering if you over do it.

 

[david85]

Forgot to mention. Pay attention to subtle changes in your pyro readings to see how it responds. To some degree, timing that is too retarded will cause higher EGTs.