My car is a Toyota Tercel 1987 4WD 1452CC DX Wagon (AL25). It has a Aisan 14120 two barrel carburetor.
Is there any rule to tune the carburetor?
I have heard that
1. Get the Idle Mixture Adjustment Screw to the fully closed position
2. Turn it 2-3 rounds to open
3. Then turn the Idle Speed Adjustment Screw to gain the best RPM.
Is the correct?
Question on Carburetor tuning
Re: Question on Carburetor tuning
It may be, but my car came with a carb that includes solid plugs over the idle mixture screw and the FSM indicates to leave it alone unless there is a known problem.
That said, the idle adjust should be set to 800-900 rpm per the spec, but that’s pretty low. If you can set it around 1,200 rpm that seems to work well. Then set high idle per the FSM and you are ready to test drive.
If your car includes the TVSV you have to disconnect/plug a port as well.
Chris
That said, the idle adjust should be set to 800-900 rpm per the spec, but that’s pretty low. If you can set it around 1,200 rpm that seems to work well. Then set high idle per the FSM and you are ready to test drive.
If your car includes the TVSV you have to disconnect/plug a port as well.
Chris
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In remembrance of my friend ARCHINSTL:
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"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
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- Petros
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Re: Question on Carburetor tuning
the way you adjust the idle mixture is, with it at idle speed, you screw it in until the motor speed slows and get jerky, than screw it out slowly, counting each turn as you go. the idle speed should smooth out, and than get rough again as you screw it out further. than you screw it back in exactly half way between the lean rough spot and the rich rough spot.
than you reset the idle speed so it is correct.
than you reset the idle speed so it is correct.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
- Dumindu
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Re: Question on Carburetor tuning
Thank you all for valuable advises.
Is there any rule for Idle Speed Adjustment Screw turning (After Idle mixture screw is adjusted)?
Is there any rule for Idle Speed Adjustment Screw turning (After Idle mixture screw is adjusted)?
- Petros
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- My tercel:: '84 Tercel4wd w/extensive mods
- Location: Arlington WA USA
Re: Question on Carburetor tuning
idle speed is set per the factory spec. I have noticed however on older worn fuel system you may not get a stable idle at the factory spec, so I always set it a bit higher, like at 800-900 rpms.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
- Dumindu
- Top Notch Member
- Posts: 227
- Joined: Wed Aug 02, 2017 12:34 pm
- My tercel:: 1987 Toyota tercle 4wd DX Wagon 1452CC
- Location: Sri Lanka
- Contact:
Re: Question on Carburetor tuning
Again, thank you very much.