Dead KZJ78. Fuel problem? (1 Viewer)

[ye olde blue]

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 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?


One of these days I'll get in the 70 series registry.

 

[AirheadNut]

Sounds like possibly a plugged pickup in the tank, if the Cruiser has been sitting for a while there might be algae growing in the fuel. What did the old filter look like when you changed it out? Does it prime with the hand pump on the filter housing?
To my knowledge there isn't a lift pump or valve in the fuel system; certainly there isn't one on an LJ78. I have a copy of the wiring manual for a KZJ78 I could send you, its all in Japanese but not too difficult to translate.

 

[Waikato Willy]

I've had most of my stuff apart on my fuel tank and there is definitely no lift pump or anything there, just a lot of complicated breather / feed / return lines that all work pretty good
When I was chasing an air leak I ran a jerry can straight to the pump and return line back to the can, strapped it to the roof and drove down the street to see if any difference

 

[ye olde blue]

Sorry for the late reply. Things got busy over the weekend then work happened.

There was nothing crazy about the old filter. I could prime by hand, albeit with great difficulty. Another suggestion I got was that the pickup in the gas tank might be clogged, so I started to remove the tank when one of the welded nuts but that the tank straps screw in to broke free on the top side of the mount. So now I either have to figure out how to cut it out myself or just send it to a shop and let them deal with it.

 

[Waikato Willy]

my primer is super hard to pump, its off a nissan patrol though
you could try a small "lift pump" at the and use it to suck fuel from the line going in to the filter, you can tell if it strains to much if you have a blockage, my old favourite "facet" fuel pumps make a cool noise like a metronome and slow down when they pressure up

 

[ye olde blue]

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.

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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.)

 

[ye olde blue]

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.

 

[JDM Journeys]

Nicely done. Great follow through, and thanks for the follow up.

I have an hzj77 but a kzj90 is my daily driver, so 1kz posts are always interesting.

Cheers! Hopefully you've solved the issue for good!