isuzu 4BD1T swap?! (1 Viewer)

[dieselcruiserhead]

It is perfectly possible the injector pumps are speced differently in different continents. Interestingly enough our friend witha BJ42 has a nearly identical device on his injection pump, did the same thing, and it is a night and day difference, all of a sudden the Land Cruiser has power at boost

 

[Dougal]

It is perfectly possible the injector pumps are speced differently in different continents. Interestingly enough our friend witha BJ42 has a nearly identical device on his injection pump, did the same thing, and it is a night and day difference, all of a sudden the Land Cruiser has power at boost

The governors on the 3B are quite different. The engine itself is throttled and the governor is pneumatic, sensing the pressure difference across the throttle.
They weren't a factory turbo engine, but putting boost to the correct side of the diaphragm will certainly help.

 

[88tlc]

4bd1t injection pump.

Photo is correct, you might need to scroll across to see the altitude compensator, depending on your screen size.

Adding boost pressure to that port is going to reduce fueling on boost.
All the different devices which can be added to the back of an A type pump work by pushing or pulling on one pin.
When that pin is pushed in, it reduces rack travel and reduces max fuel delivery.
When that pin is released, it allows full fuel delivery.

The real aneroid (which my engine has) is set off to the side of the governor housing and it's housing includes a rocker. This rocker is used to release the pin when boost pressure is added to the can.

As you can see the altitude compensator is directly inline with this pin, so adding pressure to the port on the back will push the pin into the housing, restricting rack travel and reducing fuel delivery.
If you want it to deliver full fuel on boost then you need to hook a boost line up to the other side of the can.
But such an endeavour is pointless as when set correctly, your altitude compensator won't be restricting fuelling unless at very high altitude.

Dougal,

thanks for more explanation, it sounds like you have some key knowledge as to what is actually happening on the inside of the pump. I have not taken these apart, and do not know what reaction there is to the ALTCOMP/ANEROID getting more pressure. but I am trying to wrap my mind around some key facts, and the two devices in my mind work the same. one though is for no turbo, one is for turbo.

Something above seems inconsistent. What I think we are comparing is:

ALTCOMP set up without boost, only ambient pressure. Max fuel is delivered at max pressure which is sea level. so more pressure, pushing, should mean more fuel?

Aneroid - set up with boost pressure. Again, max fuel is delivered at Max pressure, in this case max boost pressure. max pressure, pushing, means more fuel?

 

[88tlc]

4bd1t injection pump with altitude compensator

another view of this injection pump.

this is from the port side, the side that is up against the engine.

is it possible this ALT comp does have a rocker in there pulling a rod on the port side?

 

[Dougal]

Dougal,

thanks for more explanation, it sounds like you have some key knowledge as to what is actually happening on the inside of the pump. I have not taken these apart, and do not know what reaction there is to the ALTCOMP/ANEROID getting more pressure. but I am trying to wrap my mind around some key facts, and the two devices in my mind work the same. one though is for no turbo, one is for turbo.

Something above seems inconsistent. What I think we are comparing is:

ALTCOMP set up without boost, only ambient pressure. Max fuel is delivered at max pressure which is sea level. so more pressure, pushing, should mean more fuel?

Aneroid - set up with boost pressure. Again, max fuel is delivered at Max pressure, in this case max boost pressure. max pressure, pushing, means more fuel?

The operation is of the two devices is simply reversed.
The aneroid uses contained air pressure to withdraw the rod and allow more fuel.
The altitude compensator uses contained air pressure to push on the rod and reduce fuel.

To facilitate this difference, the aneroid is offset by around 40mm to the side to allow room for an adjustable rocker. The entire thing overhangs the side of the governor.

It's not a good picture, but I can't get a good photo of this area in my truck so a drawing will have to do.

The large hole shown in the aneroid mount is the location of the plunger rod. It extends through the governer housing to restrict the movement of the cam which allows rack travel. The exact same cam on the outside of the pump with the maximum fuel screw on it.
I have pulled apart both of my pumps with the intention of swapping the aneroids between them. In that I suceeded, but the drive gear bore size was different so I could not use the newer style pump.

It is entirely possible to make an aneroid from an altitude compensator, but it'll involve pulling it apart, ensuring the front side is sealed and fitting a boost line to the front chamber, not the rear one with that nipple on it.

 

[Oregon FJ80]

4BD2T in my 91 FJ80

Okay,,,, so after researching the hell out of this, i think i've found out some news,,,

I have a 93 4BD2T (Fresh Rebuild) with a 700r4 allready attached (its in my shop truck which were now replacing)

Soooo From what i've seen here on from Advance Adapters it looks like with the adapter ring that mating the current 700r4 to my diesel, i should be able to mount 4BD2T with the adapter ring directly to the stock FJ80 transmission with Advance Adapters Chevy to Toy kit. (P/N 712535-D)

Thoughts anyone?
T~

 

[dieselcruiserhead]

Check about page 4 or 5 of this thread, heavily discussed. I recommended using the 700r4 because it is valved to the lowerr shift points of a diesel. If you had a diesel spec 80 series transmission that would be fine I think, but these are non-USA.

 

[Oregon FJ80]

4BD2T in my 91 FJ80

Given the 700r4 may have better shift points, i'm looking for the most direct swap possible.

Does my assumption of the D2T set up sound correct from everyones experiance or could i be missing a step?

T~

 

[ThePookieBear]

I'm not sure, but it seems that some have said it won't work with two plate adapters. Not sure though.

 

[Dougal]

hey fellas been looking at this forum for a while now and iv'e only just registered, thought i'd let you know i'm doing an apprenticeship at an isuzu dealership here in oz so if you need any help with stuff out of workshop manuals i'd be more than happy to help, been some pretty sweet work done here to get these motors into cruisers.

If you could find the factory power/torque curves for the 4BD1T/4BD2T it'd be handy.
I have the non turbo 4BD1 curves but haven't been able to find the turbo ones.

 

[andrew.fletcher]

Can't get the FSM downloaded!!

I've been trying over the last few weeks and everytime I try to download it times out as it slows to about 5kps. Can I send someone a few bucks to have you send me a CD with the FSM??

Also, is Tom's Isuzu in Santa Ana the recommended place to get parts? I just need the bellhousing bolts, manual flywheel and valve cover bolts.

 

[Dougal]

I've been trying over the last few weeks and everytime I try to download it times out as it slows to about 5kps. Can I send someone a few bucks to have you send me a CD with the FSM??

Also, is Tom's Isuzu in Santa Ana the recommended place to get parts? I just need the bellhousing bolts, manual flywheel and valve cover bolts.

Are you using a download manager? They can often get around such problems and there are plenty of good free ones.

 

[hayes167]

700r4

Are there differences between a gasser 700r4 and one that was stock behind a diesel?
I am looking to get a rebuilt one and want to know exactly what I need to ask for. Right now I'm thinking I need one built heavy duty/towing to put behind my 4bd1t. Does it need anything else to function properly behind a deisel?

 

[rtarh2o]

I had a 700R4 rebuilt for my 6.2 conversion. I found an experienced rebuilder and told them what I was doing. I am pretty sure they used the heavy duty kit and also installed the hydraulic lock-out. As far as shift points, from what I have learned in the last couple days, you can adjust those with the TV cable and some springs that adjust the pressure. I am about to drive mine for the first time this afternoon so maybe I can tell you more then. Rusty

 

[coog]

Are there differences between a gasser 700r4 and one that was stock behind a diesel?
I am looking to get a rebuilt one and want to know exactly what I need to ask for. Right now I'm thinking I need one built heavy duty/towing to put behind my 4bd1t. Does it need anything else to function properly behind a deisel?

Make sure that you spec a low stall torque converter; the power from the diesel comes on right away,as opposed to the gasser that needs some revs to make its' power.

 

[jb BJ73]

If you could find the factory power/torque curves for the 4BD1T/4BD2T it'd be handy.
I have the non turbo 4BD1 curves but haven't been able to find the turbo ones.

should be able to do that. we've got the sales spec sheets back to about the mid 80's or so on computer as .pdf files so i'll see if i can post em from work.

 

[andrew.fletcher]

Are you using a download manager? They can often get around such problems and there are plenty of good free ones.

astr is hooking me up, thanks for the idea though. I'll have to look into that for the long term though.

 

[jb BJ73]

heres the spec sheet for the 4BD1-T.

 

[coog]

Would any of our friends in Oz be interested in sending the needed bits to convert my NPR to 4x4??? I just don't understand why we can't get them in the States,

 

[gifu]

just a quick sanity check for Hayes 167 and Oregon 80... when/if you decide to get a 700R4 built, call advance adapters first... some of their adapter kits (ie: 700R4->Fj60 splitcase) require a special shaft. Would be a shame to build a new transmission, then need to have it rebuilt with the correct shaft.