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4bd1t rebuild

Hi GruntMaster

I also am new to 4BBTSWAPS and am very interested in the rebuild mods you will be doing,

westy
 

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...I'm still hoping some one can tell me what the max fuel delivery of the pump is (per cylinder, per injection)...
Perhaps this information from my workshop manual for the 4BD1 and 4BD1-T will help. It gives the following tables for the governor performance/adjustment:

1st column - Adjusting point
2st column - Control rack position (mm)
3nd column - Pump speed (rpm)
4th column - Strokes
5rd column - Injection volume (cc / 1000 strokes)
6th column - Variance (%)
7th column - Fixed
8th column - Remarks

4BD1 with torque cam marked "A50"

A, 11.3, 950, 1000, 67.3 - 70.3, +-2.5, Rack, Basic
H, about 9.5, 290, 1000, 6.7 - 9.3. +-14.0, Rack
A, R1 11.3, 950, 1000, 67.8 - 69.8, -, Lever, Basic
B, 10.95, 1600, 1000, 67.0 - 70.2, -, Lever
C, 11.15, 1300, 1000, 70.9 - 74.1, -, Lever
D, 11.05, 650, 1000, 48.7 - 51.9, -, Lever
E, 11.4, 500, 1000, 49.9 - 53.9, -, Lever

The chart below the table shows the adjusting points A, B, C, D & E along the plot of "control rack position" vs "pump speed" and also shows "Rack limit 14.4 +0.2"

4BD1-T with boost compensator and torque cam marked "A75"

A, 11.3, 900, 1000, 69.6 - 72.8, +-2.5, Rack, Basic
H, about 9.5, 290, 1000, 6.7 - 9.3. +-14.0, Rack
A, R1 11.2, 900, 1000, 70.2 - 72.2, -, Lever, Boost pressure above 110mm Hg
B, R1 - 0.25, 550, 1000, (49.7), -, Lever, Boost pressure above 110mm Hg
C, 10.2, 550, 1000, (29.7), -, Lever
D, R1 - 0.2, 1500, 1000, 78.0, -, Lever, Boost pressure above 110mm Hg
E, -, 150, 1000, Above 90.9, -, Lever

The "Full-Load adjustment" chart below the table shows the adjusting points A, B & D along the plot of "control rack position" vs "pump speed". The control rack position for this plot is displaced by the boost compensator stroke of 0.75 +-0.1 above another plot with adjusting points C & E (no boost).

From what I can tell from the chart, the R1 in the 2nd column appears to be a reference "control rack position" of 11.2mm. So control rack position at adjusting point B (pump speed 550 rpm) is R1 - 0.2, ie. 11.2 - 0.2 = 11.0mm.

Adjusting point H is on a chart for "Idling Adjustment".

John.
 

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Perhaps this information from my workshop manual for the 4BD1 and 4BD1-T will help. It gives the following tables for the governor performance/adjustment:
bounce :eek:
Thanks John.

Assuming point E is max delivery (it might not be) it's about 20% more than that injected at 1800rpm at R1.
I hope there's a bit more headroom in it than that.
 

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Perhaps this information from my workshop manual for the 4BD1 and 4BD1-T will help. It gives the following tables for the governor performance/adjustment:
bounce :eek:
Thanks John.

Assuming point E is max delivery (it might not be) it's about 20% more than that injected at 1800rpm at R1.
I hope there's a bit more headroom in it than that.
Those figures are for calibration of the pump on the test bench. None are limits for what is possible to achieve from the pump.

Those tables were taken from the 4BD1 and 4BD1-T workshop manual. Looking in the injection pump service manual;

Adjusting point A is for setting the full load control rack position. As you know this is the screw that you adjust for more power.

Adjusting point E is for volume of fuel injection at idling.
 

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Discussion Starter #25
wow it just wanted know if a turn here and there on the pump would get some more power know this thresd got techinical on internal mods



:D bounce :idea: :D
 

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..."wow it just wanted know if a turn here and there on the pump would get some more power know this thresd got techinical on internal mods..."

What, giezy, you stupid or something? You can't follow this stuff? WELL DON'T FEEL ALONE! The main thing I would have to add to a few of the above posts is

HUH??!

Come on, guys, give us technically challenged a little break ha-ha!
 

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Okay then



These are the fuel pumps you'll find on a 4BD1T or 4BD2T.
The cam on the side is the maximum fuel adjustment. The screw on that (with the lead seal blob) is the one you adjust to change the maximum amount of fuel you'll get. Winding the screw out (lets cam move clockwise) gives you more fuel.

Tweak at your own risk and always wear an EGT gauge.:)
 

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Discussion Starter #28
I think it's cool but when it comes to internal enginering I get a little lost :( but give me the motor and parts an I mfab it into any vehicle with room or make room:rasta: just like to learn a bout the little tunes i can do later in the van for a little power and efficiency:D i kinda think it's cool you guys jumped in and added you 2 centsbounce
 

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both of those are a bit different,, and they are both a bit different from mine hmm. ok so we have the max fuel screw, now in those pics on the back of the pumps, the top one has a big "thing" and the bottom one does not, however under that big "thing" is a big nut looking debacle,,,, mine has that with what i think is a high altitude bit attached? ibelieve i can screw it in or out to change altitude performance but i'm still working on that info, however, behind that piece and under a cap, (on mine) is another screw with jam nut,,, i though that was max fuel, but maybe its pressure?? anyone know?? in the FSM it shows a pretty good reference to what i'm talking about with a cutaway showing whats under the cap.
does any of this make any sense??
 

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Whoaa Ther Nelly!!!

:nuke: I think I smell burnt brain matter coming from this thread.:nuke: Love the info, even if I'll never need it for my swap. :D
 

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both of those are a bit different,, and they are both a bit different from mine hmm. ok so we have the max fuel screw, now in those pics on the back of the pumps, the top one has a big "thing" and the bottom one does not, however under that big "thing" is a big nut looking debacle,,,, mine has that with what i think is a high altitude bit attached? ibelieve i can screw it in or out to change altitude performance but i'm still working on that info, however, behind that piece and under a cap, (on mine) is another screw with jam nut,,, i though that was max fuel, but maybe its pressure?? anyone know?? in the FSM it shows a pretty good reference to what i'm talking about with a cutaway showing whats under the cap.
does any of this make any sense??
I know what you mean.
The photos on www.isuzudieselswapper show a pump with what looks like a big pressure can on the back of the pump at main shaft level.
Inside the pumps at that point is the main spring that the governor works against, I haven't spent enough time thinking about those to figure out what the effect of playing with that spring will be.

The pump you see with the big nuts out the back is from my 86 4BD1T, the cylinder above with a hose attached is the aneroid (boost compensator).
The other pump (no nuts, no aneroid) is a rebuilt one I bought from a guy who knows nothing about it other than Isuzu 4BD1T/4BD2T. I tried to fit it to my 4BD1T but the shaft sizes have changed and the drive gear doesn't fit.:pissed:

But I learned a lot in the process. I actually swapped the aneroid and several internal governor parts across before finding they didn't fit and had to swap it all back.
 

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... however under that big "thing" is a big nut looking debacle,,,, mine has that with what i think is a high altitude bit attached? ibelieve i can screw it in or out to change altitude performance but i'm still working on that info ...
Sorry I'm not familiar with high altitude bits.

... however, behind that piece and under a cap, (on mine) is another screw with jam nut,,, i though that was max fuel, but maybe its pressure?? anyone know?? ...
The hexagon cap screws onto the guide screw. The thin nut that the cap screws up against is the guide screw lock nut.

The guide screw guides the govenor shaft. The guide screw is adjusted so that it's inner end is flush with the inside of the govenor cover - when adjusted correctly the distance from the back of the govenor cover (the surface under the lock nut) to the outer end of the guide screw, should be 14mm +/- 0.5mm.

I don't know if this value may be different on your pump with high altitude bit.

The screw you are referring to, in the center of the guide screw, is the threaded end of the govenor shaft. There are 2 nuts (lock nuts) on the govenor shaft.

The adjustment of the guide screw and govenor shaft determine the govenor spring force apposing the flyweights. Screwing the govenor shaft out (from the govenor cover) increases the spring force.

As the pump speed increases, the flyweights move out and pivot the tension lever against the govenor spring. As the tension lever pivots, it turns the torque cam. The profile of the torque cam acts as a limiting stop for other mechanisms in the govenor. The rotational position of the torque cam and it's profile (specifically designed for the engine the pump is fitted to) determine the position of the control rack.

The position of the control rack, determines how much fuel is injected.
 

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...The photos on www.isuzudieselswapper show a pump with what looks like a big pressure can on the back of the pump at main shaft level.
Inside the pumps at that point is the main spring that the governor works against, I haven't spent enough time thinking about those to figure out what the effect of playing with that spring will be...
I may be wrong, but it looks to me that, what you call a pressure can, is not at main shaft (pump cam shaft) level, but at the level of, and to one side of, the govenor shaft and spring.
...The pump you see with the big nuts out the back is from my 86 4BD1T, the cylinder above with a hose attached is the aneroid (boost compensator)...
The big nuts (hexagon cap and locknut) are inline with the pump cam shaft and the flyweights. The screw under this cap adjusts the force of the idling spring.
...The other pump (no nuts, no aneroid) is a rebuilt one I bought from a guy who knows nothing about it other than Isuzu 4BD1T/4BD2T...
That pump looks the same as the one on my 4BD1-T.
 

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the one on dieselswapper site is the same as mine, there seem to be differences in countries..
that "pressure can" is what i was refferring to as maybe an altitude thing. looks like whats on the toyota pumps.
so it looks like there are many adjustments to be made, but the main two are timing (rotate pump body) and fuel (screw/cam on side of body) is that about right??
i dont care for needing to get in and start messing around with all the other things unless they are improvements over stock as well.
on my pump it didnt get a "blob" on the fuel screw instead it has a nice cap that is semi permanent, like the caps on carbies. so i think my pump is all stock from the factory and unmolested, thats a good thing.
seems to be a bit of a dead spot between 1st and 2nd gears, not a big deal and i can compensate by revving up a bit more in 1st gear before i shift, what do ya think about that? i have the non wastegate turbo so i am thinking i dont have a boost adjustment eh?
 

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Let us know when you get gauges hooked up to it Rhino. I'm interested to see what factory boost and EGT's numbers come out like.

The other adjustments which may interest you are on top of the pump (two limit screws on one lever). They are idle speed and max speed.
 

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I may be wrong, but it looks to me that, what you call a pressure can, is not at main shaft (pump cam shaft) level, but at the level of, and to one side of, the govenor shaft and spring.
Here's the pic and you're right it's not at main shaft level.
http://www.isuzudieselswapper.com/images/dsc00066.jpg

It appears to be in the exact same location as the aneroid pushrod. So altitude compensator quite possibly. The aneroid works by restricting the rotation of the cam which the max fuel adjustment acts on. Essentially moving the max fuel limit.
Looks like the altitude compensator works the same way.

When you're feeling brave Rhino, pull it off and tell us what's there. It is external to the main pump function, so not that many bad things can happen.:D
 

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you got it dougal,,, i did point an infra red temp guage at the turbo exhaust body under load at brisk acceleration, didnt quite get to 900 F, of course that just the body and it will be a little less than the actual tamp of the air flowing inside, but its a pretty good estimate. i have played with the idle screw, lowered idle a bit to what sounded good to me, the engine runs tops and i dont want to goof it up so tinkering will be a slow deliberate process. but i will be keeping updates and my impressions.

BTW that can thing our version of what you guys got for altitude compensator, its cool bacuse i can adjust for altitude manually buy loosening the jam nut and turning the body of that cylinder.
 

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...BTW that can thing our version of what you guys got for altitude compensator, its cool bacuse i can adjust for altitude manually buy loosening the jam nut and turning the body of that cylinder.
Sorry in my earlier post, I had misunderstood the nut you were talking about.

Seeing the pic that Dougal linked to and your last post have cleared it up.

I don't have a pump with the boost compensator, and neither the boost or altitude compensator are mentioned in my engine workshop manual or injection pump service manual.

In the pic of the pump with altitude compensator, that Dougal linked to, the govenor shaft (and spring) are under the welsh plug above and to the left of the altitude compensator.

Some pumps have external adjustment of the govenor and idling springs. The adjustments have a hexagon cap over them.

The hexagon cap over the idling spring adjustment can be clearly seen on the back of the pump with boost compensator in Dougal's 1st pic. It is in line with the pump camshaft and flyweights.
 

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Some people think of boost compensators as devices to increase fuel as the boost pressure increases.

But it is valid (perhaps more so), to think of them as devices to reduce fuel and hence black smoke/particulate emission, when the boost pressure reduces.

An altitude compensator probably works in a similar way, to reduce the fuel when the barometric pressure reduces at higher altitudes.
 

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...I'm still hoping some one can tell me what the max fuel delivery of the pump is (per cylinder, per injection)...
I was looking at the technical instruction manual for the VE pump (4th edition 1999), and table 1 gives properties and characteristics data for different bosch diesel fuel injection systems.

Some of the data for the 'A' type pump (like that used on 4BD1 and 4BD1-T) are:

- injected fuel quantity per stroke 120 mm^3
- maximum nozzle pressure 750 bar
- maximum speed 2800 rpm
- maximum power per cylinder 27 kW

The power per cylinder appears conservative. 4cyl x 27kW = 108kW (~145 hp). But I assume the injected fuel quantity is determined from the plunger diameter and stroke.

FWIW, the values for the P7100 pump that the performance cummins people like are:

- injected fuel quantity per stroke 250 mm^3
- maximum nozzle pressure 1,200 bar
- maximum speed 2500 rpm
- maximum power per cylinder 55 kW

And for the VE pump:

- injected fuel quantity per stroke 120 mm^3
- maximum nozzle pressure 1,200/350 bar
- maximum speed 4500 rpm
- maximum power per cylinder 25 kW
 
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