Swapping fuel pump governors

[KiwiBacon]

So I've got two inline fuel pumps (diesel-kiki/bosch inline).

One has had about 10 years use since it was last rebuilt and is noisier than I remember it being after the rebuild. This one has an aneroid on the back. It works fine.
The other I bought for a song, was supposely just rebuilt and hasn't been used since. It has no aneroid on the back.

Since I'd like to use the aneroid, I figure I've got two options.
1. Mod the governor on the rebuilt pump to fit the aneroid (looks like a hole needs drilled).
2. Swap the governors.

How hard is it to swap governors and how much of the pump needs dismantled to get it done? I figure the individual pumps are balanced during a rebuild to deliver the same flow which is something best left to the fuel injection experts.

I'll post pictures later.

[ISUZUROVER]

I have never needed to work on a pump myself, but at one stage I owned a diesel kiki (4BD1T) pump with aneroid. I was quoted $1000 by a diesel place to fit the aneroid to my pump, and reco anything that needed doin g at the time.

[KiwiBacon]

What year was your pump with no aneroid?

My engine is 86 (jap import) and has the aneroid. The seller of the recon pump didn't know if it was 4BD1T or 4BD2T.

[ISUZUROVER]

My 110 is an '87 model, and (still!) a 4BD1 - so no aneroid. NFI what year model the other pump (with aneroid) was.

[Dzltec]

You got pics or pump numbers, it may be simple or hard, but need some info to help.

Andy

[KiwiBacon]

Here's a picture



Current fuel pump is shown on the top (a few brackets are missing).
The rebuilt one is below with the plastic plugs.

[KiwiBacon]

Knock, knock.

[Dzltec]

Kiwibacon,

if I was to do this I would be swapping the whole governor section. These RLD governors are a work of art, interfere or play with it and it turns to shite. It can be done , but special tools are needed to undo nuts inside, then it needs to be recalibrated once swapped. It may be easier to do up your old one. It wont be a 5min job.


Andy

[KiwiBacon]

Kiwibacon,

if I was to do this I would be swapping the whole governor section. These RLD governors are a work of art, interfere or play with it and it turns to shite. It can be done , but special tools are needed to undo nuts inside, then it needs to be recalibrated once swapped. It may be easier to do up your old one. It wont be a 5min job.


Andy

Thanks for the advice Andy.
I appreciate the design that's gone into these governors. I'll give it a shot on the spare and see how it goes.

When you say "special tools", how special are we talking? I have the facilities to make or modify most things, but also have a lot of other things competing for my time.

[Dzltec]

They are similar to what u made to adjust your boost compensater. generally a socket plus a fitting inside or tang sockets


Andy

[ISUZUROVER]

KB - if it isn't too much trouble - can you take a pic of the fuelling adjustment screw. It has been so long since I did mine I forgot where it is...

[KiwiBacon]

KB - if it isn't too much trouble - can you take a pic of the fuelling adjustment screw. It has been so long since I did mine I forgot where it is...

The pump on the bottom, it's the one visible on the side with the external cam against it.
On the rebuilt pump it's got wire and a lead crimp seal on it.

[ISUZUROVER]

Thanks mate!

[KiwiBacon]

Thanks mate!

Must have been right, Dzltech would have piped up by now if it wasn't.

It's been about four years since I turned that screw. Memory fades and all that.

[KiwiBacon]

Hey Dzltech.

Are there any forseeable problems with swapping just the back half of the governors?
I've got the rebuilt one apart (not off, just apart) and it appears I can swap the rear half with the aneroid. This will avoid me taking the flying weights off the main shaft (which I'd avoid if I could).

[KiwiBacon]

Okay, it's been an interesting night with the spanners.

Plan A was to modify the recon pump to accept the aneroid.
Plan B was the swap the whole governors.
Plan C was to swap the back half of the governors.

After pulling them apart and seeing I'd have to pull the fly weights off the main shaft (and make a special tool to do it), I was heading toward plan C.

After finding that the secondary shafts have different size endcaps (10mm and 14mm) I breifly considered the drill and lathe approach.

Then with the governors split, it appears to be an easy 1 hole to drill to swap the aneroid over. This hole is already cast part way and should guide well so that's tomorrows plan. Tapping the open hole in the old pump will let me block it cleanly.
I'm back to plan A.

[KiwiBacon]

It is done and appears to work. But in-vehicle testing will be a long way away.

I've gotta confess though, I was getting nervous when I had two fuel pumps governors in pieces and had to start swapping internal parts.

Here's the view inside the half attached to the pump. I had to swap the bar you can see across the middle, the one in the aneroid pump has a flat plate attached (where the "5" is cast into the case) which the aneroid push rod hits.
The two big bits on the lower shaft are the flyweights which spread out more as the speed increases.



Here's the view inside the other half. The red dot shows the point where I had to drill a 5mm hole for the aneroid pushrod.



Gotta say, it's one of the coolest devices I've ever been inside.

[Dzltec]

Kiwi bacon,

happy to see someone likes a challenge, if you are going this far, you might as well swap the torque cam, it looks like a flat disc with steps on it. This acts as a control on the rack position. It may be different to the standard one and may be beneficial.

Now you can see why I am hesitant in saying if its possible or not, these governors are an intricate piece of work, control rack movement to with .01 mm. You may be creating a headache for yourself, but no harm in trying.

Andy

[KiwiBacon]

Kiwi bacon,

happy to see someone likes a challenge, if you are going this far, you might as well swap the torque cam, it looks like a flat disc with steps on it. This acts as a control on the rack position. It may be different to the standard one and may be beneficial.

Now you can see why I am hesitant in saying if its possible or not, these governors are an intricate piece of work, control rack movement to with .01 mm. You may be creating a headache for yourself, but no harm in trying.

Andy

Well bugger it. I didn't try swapping the front gear and timing advance until I'd bolted both pumps back together. Needless to say, they changed the taper size and the f**king thing doesn't fit.

I'm sitting here trying to decide whether I swap the aneroid back again or just fit the old pump with no aneroid for the time being. My future plans do require an aneroid, so I guess that's decision made.

Where is this torque cam situated?

[Bush65]

... if you are going this far, you might as well swap the torque cam, it looks like a flat disc with steps on it. This acts as a control on the rack position. It may be different to the standard one and may be beneficial. ...Andy

...Where is this torque cam situated?

Dougal, my 4BD1-T has the RLD type governor, but doesn't have an aneroid. I had a look in my pump book and it doesn't show the aneroid on an RLD governor.

From my book:

In the bottom pic, the large spring to right of centre is the governor spring. The torque cam is close to the side of the governor spring (LH side looking from rear of engine).

In the bottom pic part of it can be seen - the bright surface about halfway down the governor spring.

The flyweights push the large sleeve (left of centre in the bottom pic), and thus pushing the tension lever against the governor spring.

A rod and spring connected between the top left (looking from rear of engine) of the tension lever, and top rear of the torque cam, rotates the torque cam on it's pivot as the flyweights push the tension lever.

In the top pic, at right of centre is the U shaped lever. Inside, and pivoting on the left hand leg of the U shaped lever (upper in pic), is the sensor lever.

The sensor lever has a fork slot at it's upper end that connects to the control rack. The lower end of the sensor lever contact the torque cam.

So the shape of the torque cam, and it's angular position (determined by flyweights), limits how far the control rack can travel to increase fuel.

[KiwiBacon]

Dougal, my 4BD1-T has the RLD type governor, but doesn't have an aneroid. I had a look in my pump book and it doesn't show the aneroid on an RLD governor.

From my book:

In the bottom pic, the large spring to right of centre is the governor spring. The torque cam is close to the side of the governor spring (LH side looking from rear of engine).

In the bottom pic part of it can be seen - the bright surface about halfway down the governor spring.

The flyweights push the large sleeve (left of centre in the bottom pic), and thus pushing the tension lever against the governor spring.

A rod and spring connected between the top left (looking from rear of engine) of the tension lever, and top rear of the torque cam, rotates the torque cam on it's pivot as the flyweights push the tension lever.

In the top pic, at right of centre is the U shaped lever. Inside, and pivoting on the left hand leg of the U shaped lever (upper in pic), is the sensor lever.

The sensor lever has a fork slot at it's upper end that connects to the control rack. The lower end of the sensor lever contact the torque cam.

So the shape of the torque cam, and it's angular position (determined by flyweights), limits how far the control rack can travel to increase fuel.

So it's on the same shaft as the cold start enrichment lever. It makes sense that the aneroid pumps would have a different cam than the non aneroid pumps.

My old one is JDM and approx 86, haven't found a casting date on the recon one yet but it's significantly different. Almost all the shaft dimensions inside are different, screw sizes and machining all have minor or major differences.
The main gasket is one of the few parts that's directly interchangable.

Thanks for your help guys.