Stuck in the jungle: Low speed shut off

[ChaseTruck]

Chase truck, I did not reset the IAC, but I just cranked it up this morning and it is idling fine now. So maybe it had something to do with the fusible link install....

Our '93 wouldn't like to run after some fusible links shenanigans. This helped:
1993 Fj80 Rough Idle, runs great other than that

I doubt IAC would cause the shutdowns, though. You state that a new EFI relay was installed - how hot (see post #9) is that relay when the truck shuts down?

 

[notathomie]

I agree. I don't think the IAC is causing the shut downs. My IAC is brand new.

The EFI relay is warm. But you can touch it without burning your hand. On my last shut down, I cranked the engine 15 times to no avail. I finally got out, opened the hood and pushed the (new) EFI relay down into the fuse box. (There was no noticeable play). It started right up. This might just be coincidence. On the next shut down, I will check to see if pushing the EFI relay down works again.

One of the leads on my original Denso EFI relay had noticeable carbon build up. It almost looked charred. A week ago I put in a new EFI relay (made by a Taiwanese company) and have since replaced it with a Denso part. The same lead on the Taiwanese part had some very slight discoloration. But hardly any.

I already cleaned the EFI relay contacts with electronic contact cleaner. I have not cleaned the contacts with a matchbook strike plate.

 

[notathomie]

I am checking back in on my hot shut off problems on my FZJ80. It was the fuel pump relay (FPR). I am writing to warn readers to watch out for false negatives on tests of fuel delivery with the FPR socket directly wired to the battery.


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The “Emergency Start Procedures” pdf was extremely helpful in diagnosing the problems with my ride (thanks buddy). Just beware of false negatives when checking fuel pumps via the FPR socket. To confirm your fuel pump is shot, definitely do the fuel delivery check one last time with the white plastic piece removed from the FPR socket before buying a new fuel pump.


I put a wire into the third receptacle of the FPR socket and connected it to 12 volt positive. No fuel emerged from the fuel regulator. So I assumed my fuel pump was dead. I was not sure my wire was getting a good contact with the female receptacle, so I removed the white insert on the FPR socket. I assume this white insert is to prevent arcing. When I inserted a wire into the third receptacle of the FPR socket with the white plastic thing removed, fuel shot out of the regulator.


I waited a month for Toyota Costa Rica to ship an FPR in from Japan. I installed it a few days ago and I have driven about 80 miles on the new FPR and have not experienced a hot shut off.


Another note on FPR failure: my relay degraded slowly. I got intermittent shut offs for awhile. But it always started back up again. After a few weeks, the hot shut offs became more frequent. And I had to try ten or more times to get the car to start. In the “death phase”, hot shut offs became a regular occurrence on each drive. And it would not start up easily. I tried cleaning the FPR contacts but it did not work (I may have cleaned it incorrectly). I had some luck getting the car to start after removing the FPR and whacking it on the hood. But who knows if this really helped or if I just got lucky.


I strongly suggest carrying a new FPR as a spare or at least a purpose made cable to make the jump from the FPR socket to 12volt positive. I would not buy a used FPR.


Thanks to everyone who helped.

 

[Maleficio]

Congrats on solving the problem. I would next have a good look at the alternator based on a couple of your comments.

 

[Wayne]

Really happy to hear you found and fixed the hot shut off problem. Great work!

 

[Lumpskie]

Thanks for checking in and updating us on what really failed. I'm glad to hear you're back on the road.