88 FJ 62 diesel conversion questions

[PurpleFJ62]

Hi all, pondering a isuzu diesel conversion in my 62. Would like to know more about what must be done to the fuel system. I know right off the bat that the diesel pump nozzle wont fit in my current filler. That should be able to be extanged for a diesel model unit, available at the toyota dealer???

On a 62, is the fuel pump in the tank? If yes or know are any mods required to convert to diesel fuel?

I believe on your typical diesel the lift pump is driven by the engine? Is this the correct assumption?

Will the lift pump suck fuel all the way from my tank and thru a filter? This has always been an area of confusion for me. Or must any aftermarket filter/h2o seperators be spliced in after lift pump and before the high pressure injection pump?

I have been thinking of many different diesel engines to use, I personally like the isuzu because I think I will be able to get one with a ps pump and a AC pump, and parts are available.
I know alot of people like 4bt's but they are rattlers IMHO. I listen to those little cab over isuzu trucks all the time and they dont seem to be too loud.

By the way, my name is nate and I think this is my first post in the diesel section. I post alot of questions in the 3rd gen 4runner section, but no one really seems to like me there to much. the 2nd gen section has been more friendly, and gave me alot of help with my last 4runner project.
hope to learn alot here.
-nate-

 

[roscoFJ73]

Hi all, pondering a isuzu diesel conversion in my 62. Would like to know more about what must be done to the fuel system. I know right off the bat that the diesel pump nozzle wont fit in my current filler. That should be able to be extanged for a diesel model unit, available at the toyota dealer???

You can use one from a diesel landcruiser ,either a BJ60,HJ60 or HJ61.
Im sure someone would have a used one in Canada somewhere.

On a 62, is the fuel pump in the tank? If yes or know are any mods required to convert to diesel fuel?

As far as I know its in the rear RH panel somewhere and you wouldn't need it anymore and it could be bypassed.
The petrol 60/62 have 3 fuel lines and diesels have 2. The 3rd line on a petrol engine is for the charcoal canister.It can be safely blocked off/discarded.

I believe on your typical diesel the lift pump is driven by the engine? Is this the correct assumption?


Will the lift pump suck fuel all the way from my tank and thru a filter? This has always been an area of confusion for me. Or must any aftermarket filter/h2o seperators be spliced in after lift pump and before the high pressure injection pump?

The injector pump sucks the fuel all the way from the tank through a filter on its own but some owners decide to help it by adding a small low pressure electric pump.I wouldnt bother unless you have a good reason.
The filters are between the tank and the injector pump.
Pumps are driven by gears off the crank or the camshaft in all diesel engines.
Its crucial they are in time with the motor to deliver the fuel to the correct cylinder at the exact time

I have been thinking of many different diesel engines to use, I personally like the isuzu because I think I will be able to get one with a ps pump and a AC pump, and parts are available.
I know alot of people like 4bt's but they are rattlers IMHO. I listen to those little cab over isuzu trucks all the time and they dont seem to be too loud.

Isuzu make great diesels and claim to be the biggest manufacturer of diesel engines in the world.
However the cheap cost maybe offset by the high cost of getting it all to fit together.
I haven't seen anyone post up pics and a story yet of a fully functioning Isuzu/landcruiser engine swap.
At the moment I think it would easier/cheaper to keep it all Toyota. At least you would have a clearer idea of the total cost.

By the way, my name is nate and I think this is my first post in the diesel section. I post alot of questions in the 3rd gen 4runner section, but no one really seems to like me there to much. the 2nd gen section has been more friendly, and gave me alot of help with my last 4runner project.
hope to learn alot here.
-nate-

Well Hi Nate,I hope I was more helpfull than the 4runner section
We like these questions in the diesel section

 

[fjbj40]

Fuel pump is in the tank in 88 fj62 North American model.
Just remove the flapper assembly from the filler neck...thats what i did.

Daryl

 

[roscoFJ73]

Fuel pump is in the tank in 88 fj62 North American model.
Just remove the flapper assembly from the filler neck...thats what i did.

Daryl

Yeah your right,there is an expansion gizmo in the rear RH panel.

 

[PurpleFJ62]

Dont diesels have lift pumps? Something to transfer the fuel from tank to injection pump?

 

[roscoFJ73]

Dont diesels have lift pumps? Something to transfer the fuel from tank to injection pump?

Not as a rule. I dont think any toyota diesels have them and mine certainly doesnt.

The injection pump can pump much more fuel than the engine needs and this extra fuel cools the pump and is returned to the tank.
Also the fuel tank is usually kept at a height close to that of the injector pump to minimise the pumping effort.

 

[PurpleFJ62]

what happans when you go up or down steet inclines?

 

[roscoFJ73]

what happans when you go up or down steet inclines?

We only drive them on flat roads

Seriously ,you've asked this question 2-3 times and if you don't believe me have a look around for yourself .
Look at the puny little pumps gassers run and very few have an extra pump to help them.
Because the fuel pump is only 6-8 inches higher than the tank it doesnt take much effort to keep the fuel flowing.
Its not the distance that counts so much in moving fluids,its the height difference between A and B


Diesels will run upside down, back to front ,underwater and in any hemisphere as long as they have fuel and air.
If you add a turbo or supercharger they will work at almost any altitude.

 

[PurpleFJ62]

no need to get angry at my ignorance :whoops: . I have just never had to deal with fuel systems before, on a gas or diesel. In fact have not had to do much engine work at all. Always took very good care of my engines. Many oil changes and such.

What is exactly inside the tank, because if it was not full I could see a potential problem. Is there just one suction point, like a hose or something? Any pics would be great.

 

[astr]

On most diesels, the lift pump appears to be part of the injection pump, but is actually a separate pump. It has the little hand pump as part of it, used to initially purge the fuel system of air. The lift pump is a mechanical pump that is driven by the same gear that drives the injection pump. It draws fuel from the tank and then pumps it through the final fuel filter before the fuel enters the "injection" part of the injector pump. This is the way I have seen it set up on the in-line injection pumps.

 

[rick_d]

fuel starvation can be an issue if upsized lines are not used. 2002 and later HZ and HDT 70 series have 12mm supply lines. Many of the conversions with 3/8" lines have added a booster pump (electric) to kick the fuel up to the primer etc.

I have a 1980's converted BJ70 series with 1HD-T. I used factory primary 12mm (firewall) and secondary supply lines AND a 12mm factory fuel tank pick up and bent 1/2" (12.7mm) line for the 3rd line which only exists in factory pickup/troopie versions (too long for my application).

I used a factory prefilter/primary filter w/ pump primer on the right fender (80 series are on the left). I have zero fuel supply issues.

lift pumps or secondary pumps are for smaller supply lines. make the lines big and have no issues.

 

[PurpleFJ62]

if I had to use a electric booster pump how exactly do I wire it up. Such that when the key is turned on its on. But say If I am sitting in a parking lot with the radio on, than my electric pimp is still on and its pumping fuel to an engine thats not running. I would love to get some info on the wiring part...thanks -nate-

 

[roscoFJ73]

fuel starvation can be an issue if upsized lines are not used. 2002 and later HZ and HDT 70 series have 12mm supply lines. Many of the conversions with 3/8" lines have added a booster pump (electric) to kick the fuel up to the primer etc.

I have a 1980's converted BJ70 series with 1HD-T. I used factory primary 12mm (firewall) and secondary supply lines AND a 12mm factory fuel tank pick up and bent 1/2" (12.7mm) line for the 3rd line which only exists in factory pickup/troopie versions (too long for my application).

I used a factory prefilter/primary filter w/ pump primer on the right fender (80 series are on the left). I have zero fuel supply issues.

lift pumps or secondary pumps are for smaller supply lines. make the lines big and have no issues.

If the petrol 3F uses %25 more fuel than a 1HZ/D-T why doesnt it get starvation issues with a 6mm fuel line?
Im still using the 6mm line on my FJ73 and no issues and I will be putting it on the dyno in the near future for a service
My old 3F could use well over 20 litres an hour and the 1HZ uses 15-16 an hour under heavy going at 120 klm so why would you need a bigger fuel line.

I can appreciate Toyota did it for a reason but Ive never seen or heard of anyone with fuel starvation issues.

The turbo versions use the bigger fuel line and I think Toyota decided to use one size fuel line for all and particularly when they began to fit the 1HD FTE to the 78/79 series.

I think the larger fuel lines are there in an attempt to cool the injector pump as the pumps on these have been the weak link since the inception of the 1HZ/1HD T.

 

[brownbear]

The answer IMOP Rosco is flow. Like you said the pump pulls more fluid than needed and cycles it back again. SO it needs more flow.

Restricting the flow may not cause starvation problems, but may turn up that the parts are not cooling or be lubricated by the fuel enough. Thus causing premature wear.

That's why I think they may have a larger diameter line.

As for wiring of a boost pump, they should be wired to be on when the ignition is on. But I think the standard pumps put out too much pressure and could cause problems with an inline pump. They were not meant to have posistive pressure IMOP.

I would not run a pump unless I had amassive filter in place to knock down the PSI. If your running factory filters no need for pump. Just no need.

 

[PurpleFJ62]

in wiring the booster pump it will be on all the time, when key is turned. Is there some way you could wire it up so it was only making oressure when the engine was on. Like wire it to the altornator????

 

[astr]

If you insist on using an "electric boost pump", use a pump designed for a carburated car - they only put out low pressure (1 - 2 lb) rather than a pump designed for a fuel injected car (capable of 100 psi). If the car originally had a gasoline engine, the ignition switch has terminal that is hot when the key is in "start" and "run" positions. This is where you would wire the pump.

 

[roscoFJ73]

The answer IMOP Rosco is flow. Like you said the pump pulls more fluid than needed and cycles it back again. SO it needs more flow.

Restricting the flow may not cause starvation problems, but may turn up that the parts are not cooling or be lubricated by the fuel enough. Thus causing premature wear.

That's why I think they may have a larger diameter line.

.

I asked 2 very experienced diesel techs and they reckon dont worry about it.
One of them (with 30 years exp) believed the earlier 1HZ/1HD T may get a harmonic hum or vibration from the timing gear. I think the later models 96- had different gears.
He told me early pump wear in the Denso rotaries had always been a mystery because the Zexel rotary pump pump used on 6cyl 4.2 Patrols had a smaller dia pump shaft and smaller bearings ,yet was getting over 400000 klms between rebuilds.
In diesel pump circles ,bigger dia shaft and bearings is supposed to be better.
The difference was 18mm vs 21 mm I think.
He showed me a box of destroyed 1HZ pump parts and it was hard not to agree with him.

I may pull the return line off and measure the flow and temperature after its warmed up just to see whats happening.

 

[PurpleFJ62]

thanks for the info. On my 62 would it be a good idea to use the stock fuel lines, so to fab up a new system of stainless braided hose? Or custom bend hard lines? If you can do that.

 

[roscoFJ73]

thanks for the info. On my 62 would it be a good idea to use the stock fuel lines, so to fab up a new system of stainless braided hose? Or custom bend hard lines? If you can do that.

If you want to change to 10mm diesel fuel lines,which is what a HJ61 diesel has,I would contact G&S cruisers or Radd cruisers. One of them was stripping some diesel 60 from Japan.
For the engine bay you could buy a flare and bending kit and make your own.
Or you could use straight pieces of metal fuel line and connect them with rubber fuel line at the bends.

The Isuzu 4.2 engines Ive looked at use the same filtration and similar Denso rotary pumps so you should have a look at that fuel system for any bits and pieces you can use

 

[Greg_B]

If you want to change to 10mm diesel fuel lines,which is what a HJ61 diesel has,I would contact G&S cruisers or Radd cruisers. One of them was stripping some diesel 60 from Japan.
For the engine bay you could buy a flare and bending kit and make your own.
Or you could use straight pieces of metal fuel line and connect them with rubber fuel line at the bends.

The Isuzu 4.2 engines Ive looked at use the same filtration and similar Denso rotary pumps so you should have a look at that fuel system for any bits and pieces you can use

Thanks for the rops rosco. Just about evey fuel line we ever strip off goes with the engine to the buyer, for ease of install. We might have something on the wall, but Sheldon would know better then I.

As bb and rick_d have mentioned, it is about flow and making sure the pump has the fuel to lubricate and keep cooler. Many people (go to the 80'scool list, or check out Willam-Jans site) with HD-T's have put a low pressure pusher pump at the rear, thus making sure fuel volumn is there. Responses are quite positive. If one was also to run additional filters the pusher pump will ensure there is no starvation issues, as the stock pump may well have issues drawing fuel through.

I think it's one of the best things you can do for your pump, much the same as re and re the connecting rod bearings to ACL on any 1HD-T/FT/HZ.

hth's

gb