'88 FJ-62 fuel/ignition problem

slingle

slingle

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Jun 9, 2021
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Location
Pennsylvania
Hi all,
I have a 1988 FJ-62. I'm having a problem where cyls. 1,2 and 3 are loading with fuel. There's spark in those cylinders, but there's so much fuel that it's just blowing it straight through and out the exhaust. It has new plugs and new injectors. It runs, just really rough. I'm hoping someone here will know where to start looking to solve this issue. I really don't want to give up on this thing.

Any help is greatly appreciated.

Cheers & Thanks!
 
L

Lead Head

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Jul 21, 2012
Messages
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Location
Rhode Island USA
The engine has two "banks" for fuel control. Cylinders 1, 2 and 3 are one bank, Cylinders 4, 5 and 6 are on another.

There are only two things that could cause what you describe:
1) Failed front oxygen sensor, causing the computer to inject more fuel into those cylinders
2) Short in the injector circuit, causing the injectors to stay on the entire time.

Easy thing to do would be to disconnect the battery and unplug the oxygen sensors. See if it runs better.
 
4Cruisers

4Cruisers

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The FJ62 factory service manual (FSM) has a detailed section on engine codes and troubleshooting. It contains a lot of information and can be intimidating at first, but checking the diagnostic codes is really simple - no code reader required.

See Post #2 here for a link to the FSM you need:

 
slingle

slingle

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Pennsylvania
@Lead Head - Thanks. I'll try that out and see what happens. Was trying to figure out why it would only be those 3 cylinders, but that makes sense to me now.

@4Cruisers - I didn't think we got anything useful out of diagnostic, but will definitely check that again. Thanks! And thanks much for that link.

Cheers
Scott
 
cruisermatt

cruisermatt

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If you are not getting a CEL then you're not going to get a code.

As @Lead Head stated I would start with unplugging the front bank's O2 sensor. When you go to do that you will probably find it's melted wiring. Post up your results
 

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