Wotcher Guv'nor

[abaddonxi]

I've been driving around in the new toy for a few days and I'm noticing there's a governor. I dunno if it's the LT85 in this one rather than the LT95 in the previous, but I don't remember the governor, or don't remember it coming on quite so quick.

Now I'm starting to wonder what happens when I add a turbo to it?

So, can someone explain how this all works?

Assume I know nothing.:D

Simon

[Blknight.aus]

the govenor is a magic bit of balancing....

essentially some weights get thrown about with engine speed and some springs try to keep them in check. in a fixed speed engine (like a genset) thats all there is the govenor is set at one speed and will do what it can to make sure that RPM is maintaintained.. Great for gensets bad for cars

so we have what was once known as the variable speed govenor its essentially the same but your throttle pedal links into the balancing act in such a way as to bias the tension on the springs or the weights..

in both cases the springs and weights move the bit of the fuel injection system that controls how much fuel is going into the injectors to feed the engine.

if the weights are winning the tug of war then the engine is going too fast so they will act on the fuel control to reduce engine speed

if the springs are winning then the engine fuel control is acted on to add more fuel as the engine is going too slowly.

think of it this way...

when you stomp on the loud pedal you are not asking the engine to make more power but to make more RPM's

the throttle pedal usually has no direct influence on how much fuel is going into the injectors it acts indirectly by changing the balance point of the springs and the weights.

once you get around all that there are a couple of limits that are imposed on the system by the designers the first is Idle speed, this is the point where the engine idles and the springs counter the weights at the lowest speed the engine is designed to turn at. The other other is the max speed limiter and this is essentially the point where you can no longer influence the springs to overcome the weights which means you cant use the noise pedal to make the engine over rev.

theres lots of ways you can govern a diesel with electronics, air pressure, mechanically (the most common but being replaced by electronic means) hydraulicly or a combination of the above. You can also govern for torque, power or as already covered RPM.

there is also usually a method of causing a shut down, it used to be a case of just winding the springs back till the weights pulled the fuel control all the way off but you can also do that manually as per the old 2.25 diesel and the series, or you can turn the fuel off electrically (like a tdi) turn the injectors off electronically (like a TD5).

thats basically govenors.

[rovercare]

Motor revs, spung wieghts do there thang and stop putting fuel in at Xrpm;)

Easily adjusted via a cap on front of the pump, when you fit the Turbo, you'll have a HEAP more grunt down low, so easier to get the next gear

[rovercare]

^^^^I think you've got the long AND the short version of it:D

[abaddonxi]

^^^^I think you've got the long AND the short version of it:D

Ta, ta, :D.

[B92 8NW]

If you want the bloody long version, I have just finished reading a Bosch manual titled "Diesel Engine Management". It was intense. 500 pages. Very good insight if you've got nothing to better to do with the time.


here - http://www.pitstop.net.au/view/products/page/query/plu/15092/
shorter one - http://www.pitstop.net.au/view/products/page/query/plu/8578/

[Blknight.aus]

so you got the abridged version then....

[isuzubob]

I've been driving around in the new toy for a few days and I'm noticing there's a governor.

Simon

Check also for restrictions under the pedal as well as the lock bolt under the pedal is adjusted correctly. When I pick up my '88 County four years back it didn't seem to want to rev out as the carpet under the pedal was stopping me getting full travel. That was an easy fix:D

[abaddonxi]

Ah, swings and roundabouts.

Went out for a long drive the other day and noticed some irritating black smoke.

Drive to the governor, shift up and give it a bit of stick to get it going and instead get the farty noise and puffs of black smoke.

If I did it all with a little less fast pedal everything is fine.

But not quite what I want.

So I'm guessing not enough air, too much fuel, fit a turbo.

More explanations how this works, please.:)

Simon

[rangieman]

^^^^I think you've got the long AND the short version of it:D
As always matt short and sweet;)

[Bush65]

Illustration of type RLD governor as fitted to the A series injection pump used on Isuzu 4BD1 and 4BD1-T.

Black smoke is a result of fuel that has not been burnt completely - often because there was not enough air (could be other reasons such as poor fuel atomisation).

The air may be restricted somewhere in the intake/filtration system.

Turbocharges are great for diesel engines, which like high air/fuel ratios - low air/fuel (rich) results in black smoke and higher exhaust gas temperature.

The maximum fuel adjustment on the governor is easy to adjust for more fuel when a turbo is fitted. This is usually required to get more boost pressure (unless the turbo fitted is on the small side).

Several threads in this forum go into more detail on fitting a turbo. From memory the most recent was started by Isuzurover a few months ago.

[clean32]

Illustration of type RLD governor as fitted to the A series injection pump used on Isuzu 4BD1 and 4BD1-T.

Black smoke is a result of fuel that has not been burnt completely - often because there was not enough air (could be other reasons such as poor fuel atomisation).

The air may be restricted somewhere in the intake/filtration system.

Turbocharges are great for diesel engines, which like high air/fuel ratios - low air/fuel (rich) results in black smoke and higher exhaust gas temperature.

The maximum fuel adjustment on the governor is easy to adjust for more fuel when a turbo is fitted. This is usually required to get more boost pressure (unless the turbo fitted is on the small side).

Several threads in this forum go into more detail on fitting a turbo. From memory the most recent was started by Isuzurover a few months ago.


Thanks

whats the difrence between the Idling set bolt and the idling spring assembly. IE what one should i ajust if i want a bit of a higher idle

[Blknight.aus]

the quick and easy way is to adjust one of the 2 bolts that act on the lever that the throttle cable hooks up to when at rest you will see one bolt is stopping the lever moving back towards the cable any further, just wind that in a turn or 2. the other one sets the maximum throttle position.

[clean32]

any one have the same picture but for the pump side?

[Bush65]

Adjust the idling set bolt as Dave said.

The idling spring is adjust to obtain a specific rack position at a the specified pump speed when the control lever is held against the idling set bolt.

[Bush65]

Exploded assy

[clean32]

OK looking under the bonett, following the fule lines, is the governor full of diesel as its lubricant?
and where do i ajust to cut down on my over fueling ?

[Bush65]

Unlike the VE pumps, which are lubricated with diesel, the inline pump is lubricated with engine oil.

Full load fuel adjustment is outside, on rh side of the governor housing. You will see a cam like plate that rotates with the end of a spindle that protrudes through the housing.

The screw that you adjust, acts as a stop to limit how far the cam/spindle can rotate. Turn the screw in toward the cam plate to reduce the full load fuel rate. Usually there is a tamper proof shroud over the screw head and lock nut.