KZJ78W dead. Fuel starvtion??

ye olde blue

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I just got my 1994 KZJ78W here in the US after driving it in Japan for three years. While there, it ran nearly flawlessly and started up perfectly after letting it sit for months while I was gone. Here is a different story. I drove it about 30 miles home from the importer to my house with no issues, it sat overnight and I drove it five miles to work and back the next day. Again no issues. On the third day, the problem arose. I turned it on to go to work, drove about 200m out of my driveway and it slowly died. Suddenly I heard a whining from the fuel tank area. My Subaru STI has an upgraded fuel pump, and it sounded just like when that primes. Moments after this whine started, I lost power and was barely able to pull over before the engine cut off. It wouldn't start to save its own life.

Once towed into my driveway, I replaced the fuel filter with one from Napa. When removing the fuel lines, there was zero fuel spill as they were pretty dry inside. I pressurized the return line and again it made the same whining noise and fuel eventually reached the filter.

Does anyone know if there's some sort of solenoid or valve in the supply line? It seems impossible to find any manuals on the KZJ78W as it was only really available in Japan. I have a book for the 1KZ-TE engine, but it doesn't mention anything before the fuel filter. Does anyone have any ideas what this whining noise could be?

Any help is greatly appreciated!
 

Tractionman

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Just a shot in the dark, is the breather hole in fuel cap blocked, or associated pipework in/ out of fuel tank.
Normally the giveaway with that is pressure being released when cap removed, see if it runs without cap.
IIRC, the fuel shut off solenoid is in the engine bay.
Hang in there cos there are some good 70 series lads on here, with vast experience of your engine.
 

goodoldboy

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Hello Pete & welcome . The same engine is used in the 90 series & some areas to check are the fuel pick up inside the tank - they tend to rot away. Also the spill control valve (SCV) can be problematic .hope this helps
 

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Shayne

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Does the 1KZ have a spill control valve same as the 1KZ-TE ?

My first line of attack would be to drop the fuel tank for inspection and if all is good the filter housing would be suspect .
 
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ye olde blue

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Remove the cap and no pressure change. Still couldn't get it running, so I moved on to dropping the tank. As I was taking off the tank straps, one of the welded on nuts broke free so one bolt just spins. Now I have to decide trying to cut it out myself or sending it to a shop and letting them deal with it.
 

Shayne

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I don't know your particular cruiser but its just a strap so drill out the old and use a new nut and bolt ?

A shop will do the absolute minimum to get you going again whereas if you do it yourself you can make things good for another 20 years .
 
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wobbly

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Is there an inspection hatch in the rear load area that gives you access to the top of the tank, if so can the unbolt the in-tank unit and lift it out to check it?

Sounds like a fuel pumping problem.
 

Tractionman

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Presumably you have primed and bled the system, is there fuel filter full and fuel actuallly reaching the injector pump? Maybe if it had a rough crossing over, bits of rust/ crap have become dislodged and blocked lines, therefor the dropping of the tank, as already suggested, is good.
I changed the filter on lj78 years ago and that wouldn't prime/fill the filter after. I got a cheap pull/push 12v pump, and connected that between the filter and pump. That dragged the fuel through, disconnected 12v pump, connected fuel line and bled, no trouble any more. Just more ideas to add to the mix. Good luck !
 

ye olde blue

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TLDR: 1kz runs after reinstalling the fuel tank with no changes, but now with a lot more oil related issues than the prior three years of ownership.


A slightly more loquacious update on the situation:

Pulled the tank to check the pickups. The filter wasn't clogged and the pickups themselves look in decent condition (Unless I don't know what I'm looking for). Let me know if I'm dead wrong.

IMG_20201108_131857175_HDR.jpg
IMG_20201108_131834157_HDR.jpg

I put it all back together, primed it for a long time, and it decided to start back up...albeit running extremely rough for about 30 seconds and nearly unresponsive to throttle input. When I stepped out to do a walk-around, I noticed it was pretty smokey compared to the last three years where it was perfect. It was a nice blue smoke and it even left an oily skidmark on the ground. Both of these symptoms are new.

I took it for a drive around the block and the oil pressure light came on a couple times and it started to die, the the light went off and the power came back in full. Oil level is well within limits, erring toward low.

(In Japan I would sporadically get this same oil pressure light coming on, but no changes in power or function. It seemed more like an electrical short, then the gauge would also jump back into operation.)


IMG_20201111_164558819_HDR.jpg
 
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Shayne

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A bit of research suggests your engine is 1KZ-TE so assuming that "oil" is diesel suction control valves could be the problem , fuelling is electronically controlled so that might explain why it feels like an electrical fault .

I'm guessing by the way but the control valves are known to fail eventually .
 

ye olde blue

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A bit of research suggests your engine is 1KZ-TE so assuming that "oil" is diesel suction control valves could be the problem , fuelling is electronically controlled so that might explain why it feels like an electrical fault .

I'm guessing by the way but the control valves are known to fail eventually .

Would you also call this the spill control valve?
 

Higgy

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Have you tried the good old straight from a can to the Injector pump, Just run fuel from a can Direct to the pump, That will Eliminate any problems with air getting in /blockages /Primer housing etc etc ...Its always my first thing to try when there are Fuel related Headaches.....
 

ye olde blue

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This would've been my next step, but it's running again. Today, as I drove it around the block it shut off. When I went to prime the system, fuel started coming out from the Heater Assembly! This makes total sense why every time I go to start it I have to prime it again. I'm going to call Toyota tomorrow and see if they even have these in the US.

One more thing soon to be fixed.
 

ye olde blue

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Final update...hopefully.

One time my Landcru died, I was priming the fuel system with the pump and noticed a significant leak around the fuel heater in the cap assembly. Once I got home, I pulled the heater element and attempted replacing the o-ring itself. No o-ring at Napa Auto Parts fit perfectly and the one I selected didn't do the job. I looked all over for a fuel heater, but they were either out of stock or exorbitantly expensive. In the end, I bought a new cap assembly, fuel filter without the heater (23301-54620) from partsouq (very fast btw. Ordered on a Saturday, part arrived from UAE to WA state on a Wednesday). After replacing the old cap, my Landcru started on the fourth crank and ran perfectly for the 20 minutes I drove around.

I guess the moral of the story is: When you hear hoofbeats, look for horses, not zebras.
 

MailEscort

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I had this exact issue last fall, new filler cap, filter housing and heater fixed it. I'm sure it was a leak in the primer pump, it would allow fuel to drain back to the tank overnight. Wish I had seen this thread earlier. Glad it's running now!
 
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