Does my Prado (KZJ78) have a fuel lift pump? (1 Viewer)

[Joshua225]

I'm digging around in the electronic parts catalog (EPC) and don't see a lift pump in the tank, on the injection pump or elsewhere. Has anyone done a fuel delivery/supply write-up? I can see all the parts in the EPC, but it would be nice to understand the basic fuel delivery.

It's 18°F outside and while the engine started on the 3rd try it then died after maybe a minute of running. I'm attempting to warm the engine and fuel system to see if I can get it going. My uncle is in the hospital and probably won't make it and I'd like to visit.

 

[AirheadNut]

I don’t think there is a lift pump on those, there isn’t one on an LJ78 and the fuel systems are pretty much the same. Did you use the manual throttle to let it idle high (1200rpm or so)? At 18°F you shouldn’t have issues with fuel gelling, but it probably wouldn’t hurt to put some additive in the tank.

 

[Joshua225]

Yes, I hit the Idle Up switch and the RPM came up for a little before it stumbled, recovered briefly and then died.

I put a propane heater under the engine while I recharged the batteries. It still didn't want to start, but then I discovered the primer on the fuel filter mount. It pumped easy for about 8 strokes then got firm. It started normally on the next attempt. My glow plug light is out so I had been jumping the gun with cranking. But now I have to figure out why I don't have 4WD. I suspect hub motor brushes as I have 228k km on the clock.

 

[AirheadNut]

Glad to hear you got it running. If I were the betting kind I would lay good odds on your fuel filter housing having a leak and letting air into the fuel system. For some reason I assumed you have a KZJ78, but now noticed that you didn't specify in your original post. What model is your Prado?

 

[Joshua225]

KZJ78W to be exact. Yes, the filter housing is leaking. There was fuel on top of it when I opened the hood. I'll be ordering all the seals.

 

[AirheadNut]

You're best off just getting a new filter housing/primer pump. The filter o-rings don't generally fail, it is the primer pump that tends to leak and I don't believe the primer pump is serviceable. The part number is 23301-54620 for the filter housing for your model.

 

[AirheadNut]

For the glow plug light I would check to see if the bulb is burnt out, otherwise you might have a fault in the glow system.

Lack of 4WD is most likely a problem with the electric hubs, they're actually fairly easy to service if they haven't been mangled by a previous owner or shop. Lots of good info on those here on Mud.

 

[Joshua225]

You're correct, Toyota doesn't offer any parts to rebuild the primer. I'm not a big diesel guy, but what little I have done has been more industrial and serviceable. My Prado's fuel filter mount has the heater so I'm looking at p/n 23301-54630. I'll examine it closely to see if maybe it's the heater or its seal that is leaking. Of course the heater o-ring isn't serviced separately.

The glow system is working. I can see the voltage sag abate when they turn off.

I have done some reading on the hubs elsewhere. Hopefully it's just worn brushes. I like the auto hubs. Especially since it's so expensive to swap in manual hubs.

 

[AirheadNut]

I'm in the same boat with the electric hubs. Have considered swapping to manual hubs several times but I can't bring myself to spend the money. Besides, the convenience of the electric hubs is really nice (until they don't work when you're stuck in an icy mud puddle...). I have had mine apart a couple of times, really the only trick to them is getting the correct grease and making sure to properly retain the brush holders upon reinstallation.

 

[Tigris]

I'm in the same boat with the electric hubs. Have considered swapping to manual hubs several times but I can't bring myself to spend the money. Besides, the convenience of the electric hubs is really nice (until they don't work when you're stuck in an icy mud puddle...). I have had mine apart a couple of times, really the only trick to them is getting the correct grease and making sure to properly retain the brush holders upon reinstallation.

That right there is correct ^

Toyota prescribed a specific grease for the hub. Many of the issues with the electric hubs were stemming from not using the correct grease in there. I learned that the somewhat hard way.

After I took the hubs apart again and ultrasonically cleaned them from the wrong grease I put. Using the correct stuff ended my hubs issues. The only downside is that the good stuff ain't cheap. I wonder if there is a non-toyota product out there that has the same or similar formula

 

[AirheadNut]

I used Molykote 44 Light as a substitute for Toyota Castle Body Grease, at the time is was significantly cheaper and according to documentation someone here dug up it has basically the same properties.

 

[Joshua225]

I went to start the Prado this morning at 20° F and had the same issue as yesterday. It starts easily then dies. I caught it the first time it stumbled by operating the primer, but then it quit. Priming produces fuel at a little cutout on the metal fuel heater body where you can see the nylon(?) innards. If I knew the dimensions of the heater o-ring I'd get one locally.

After writing that I decided to open up the fuel heater and see if my Harbor Freight o-ring kit might have anything for me. The cutout I described is one of the notches where the metal cap snaps onto the nylon body of the heater. The nylon body and the brass heater element both have two o-rings, one large, one small, which seal it to the filter mount. To keep fuel inside the filter mount both large o-rings need to seal. The large heater element o-ring was hard as a rock. I had to stretch the p!ss out of one of the o-rings to get it to fit, but at least the truck runs.

 

[Joshua225]

My locking hubs work! Next traction improvement is probably a locker in the rear. Anyone use the Yukon Grizzly Locker? Do I want the V6 version?
I'm still getting a little air in the fuel system when the truck sits for a while so I have a new fuel heater on the way. Hopefully that's the only air leak.

 

[Tigris]

My locking hubs work! Next traction improvement is probably a locker in the rear. Anyone use the Yukon Grizzly Locker? Do I want the V6 version?
I'm still getting a little air in the fuel system when the truck sits for a while so I have a new fuel heater on the way. Hopefully that's the only air leak.

A little something about air leaks into the fuel system.
In terms of the supply/return fuel loop (aside form the rigid metal lines), you really only dealing with three different sizes of rubber lines. Getting a few feet worth of some good quality rubber hoses like the ones from Evil Energy, would be a wise and cheap investment. A few OE style constant pressure clamps will finish it all off. Nothing is more annoying then hard starts, actually, there's a quiet few things that might be more annoying

Good luck!