Question about oil pressure and engine hesitation.

Joined
Apr 3, 2005
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Kyunggi, South Korea
Hi,
I have two question about my 3F carb. motor powered FJ62

1. Oil pressure drops when engine is hot and idle.

After I start engine, oil pressure guage indicates about middle of guage whether it's idle or running.
But when engine is hot and idle, it drops to bottom and start running, it goes to middle again.
Which is suspect ? Engine oil, oil pump, or relief valve ? ....


2. Engine hesitate once when I accelerate.]

When I press acceleration pedal, it hesitates once and start running.
This happenes everytime whether engine is hot or not.
I suppose this might be realted with carburetor but I don't know.

Could anybody help me ?

Thank you,

Oh, Min Seok
 
Joined
Jan 8, 2004
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I have zero experience with your non-us 62's - that said...

sounds like your carb has a "stumble" in it. Mine is exactly the same (carb'd 2f) - stumbles right at 1100ish rpms every time - hot or cold. I intend to rebuild mine - hopefully that will fix it.

as for the first question - what weight oil are you running? i think that as it thins/heats up it will fluctuate more - but this is just a guess. someone will likely chime in w/ more experience. I run 15-40 Delo. great stuff.

hth - good luck

rob
 
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sl33py said:
I have zero experience with your non-us 62's - that said...

sounds like your carb has a "stumble" in it. Mine is exactly the same (carb'd 2f) - stumbles right at 1100ish rpms every time - hot or cold. I intend to rebuild mine - hopefully that will fix it.

as for the first question - what weight oil are you running? i think that as it thins/heats up it will fluctuate more - but this is just a guess. someone will likely chime in w/ more experience. I run 15-40 Delo. great stuff.

hth - good luck

rob
Thank you for your kind answer.
My FJ62 has no EGR craps. (No EGR related systems, no charcoal canister)
So, It may be similiar with de-smoged US FJ60. It's very simple configuration.
When Idling and if I press acceleration pedal, engine stumbles but if I press very slowly, don't.
I can't find reason why it does.

I use 5W-40 engine oil through all year.

Thank you,

Oh, Min Seok
 
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Messages
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I did some more rearch about my hesitation.
When I press accelerator pedal, fuel is discharged from primary small ventury and then, hesitation happened.
It looks like too much fuel cause hesitation.(only my assumption)
Are there any guy who know about this kind of phenomenon ?

Oh, Min Seok
 

Tapage

Club 4X4 Panamá
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I thought the hesitation taht your feel aren't related with oil press .. but if you want to be safe, test your oil press with a Oil Press mechanical gauge .. and check it ..

Need to be aprox 62 psi @ 2000 rpm at normal operation temp.
 
Joined
Feb 27, 2002
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Do you know how to rebuild your carburator? If you do, (or think you can) you could replace the accelerator pump in the carb and it might solve your problem. The discharge of fuel when you depress the accelerator pedal IS the issue here, in your case (probably) not enough fuel being discharged, resulting in the stumble. You see, the idle circuit in the carburator works independent of the others. So does the main metering circuit (ok, let's suppose here). The accelerator pump discharges a jet of fuel to "smooth over" the transition between one metering circuit and another, so that you don't notice it.
But you do, and that's the stumble or hesitation.
Try it, rule the accelerator pump out and we can suggest different things if it doesn't work.
 
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Feb 27, 2002
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oh, and about the low oil pressure, first of all get a mechanical gauge to give you an actual pressure reading (the factory and most electrical gauges use a sending unit and a wire, not an actual small diameter oil hose to the gauge itself) before you try other stuff. While having 50-60 psi is great, the factory manual (1991 3FE) says:
@ idle (650rpm) 4.3psi or more,
@3000 rpm 36-71psi
You might still be ok...
 
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crawlin60 said:
Do you know how to rebuild your carburator? If you do, (or think you can) you could replace the accelerator pump in the carb and it might solve your problem. The discharge of fuel when you depress the accelerator pedal IS the issue here, in your case (probably) not enough fuel being discharged, resulting in the stumble. You see, the idle circuit in the carburator works independent of the others. So does the main metering circuit (ok, let's suppose here). The accelerator pump discharges a jet of fuel to "smooth over" the transition between one metering circuit and another, so that you don't notice it.
But you do, and that's the stumble or hesitation.
Try it, rule the accelerator pump out and we can suggest different things if it doesn't work.
Thank you for your kind answer.
Yesterday, I disassembled carburetor and cleaned, checked.
I checked pump operation also and found it operates well.
Everytime I press carburetor accelerator pump by hand, fuel was discharged from jet(It looks like needle) very well.
In Korea, because my FJ62 is unique 60 series landcruiser that getting part is always problem.
So I must order parts to other country.
Following your suggestion, I'll change accelerator pump but it'll takes some time.
Thank you again.

Oh, Min Seok
 
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Tapage said:
I thought the hesitation taht your feel aren't related with oil press .. but if you want to be safe, test your oil press with a Oil Press mechanical gauge .. and check it ..

Need to be aprox 62 psi @ 2000 rpm at normal operation temp.
Yes, I think so.
Low oil pressure has no relation with hesitation problem.
Now she's running more than 9000km after last changing oil that I'll change motor oil and inspect more.

David, Do you know ? I love your land cruiser and cruising way. Especially on muddy road :D
It looks like real land cruising :)
I want to see your land cruiser and trailing pics more.
If possible, could you please inform me about link where I can see more pictures ?

Thank you,


Oh, Min Seok
 
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sound like the acelerator pump Couldbe do for a replacement to me. Ive never worked on a cruiser carb befor but on all the chevys ive had it would either be the acelerator pump or a dirty needle valve inside the valve body of the carb. You may be able to take the top off pull out the needle valve and clean it with realy fine emerycloth and stick it back in
 
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I changed to noew motor oil (same 5w40) and oil pressure drop problem was disappeared.
So, I think it was caused by poor quality of old motor oil.
But still I can't figure out hesitation problem.

Thank you,

Oh, Min Seok
 
Joined
Jun 6, 2011
Messages
6
Did you come right here. I have the same issue where it hesitates. (3F, with standard carb)
I rebuilt my carb last night (OEM Toyota rebuild kit), replaced everything that is concidered to be a consumeable (Including the accelerator pump plunger, the new plunger sealer from toyota looks to be leather) except the little ball that was at the bottom of the sleave accelerator sleave. Was battling to get the retainer off in the bottom of the sleeve, to get the ball out.

Well if you came right with this hesitation let me know.
Thanks,
Spencer
 
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