ok hey guys its been awhile .hope all is good in terclandia.
got a carb question that one of you might be able to help me with.
my engine is a 3A I have a sealed type carb so I only have that one idle adjustment screw .(the one in the middle passenger side ). somehow with a little help from a friend of the family the screw adjustment got unscrewed or screwed I should say .my question is : what is the start off point for the screw ? example : do I screw it all the way in then turn x amount off times then proceed with adjustments when engine warms up ?it seems when I tried to screw it in ( til it stalls a little then back it off ) it speeds up . and then when I try to back it off (til it stalls a little) it just keeps going and I stop for fear of the screw coming out . just want her royal highness "the tercy" to be the best she can be . thanks guys
carb adjustment is skrewed
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gnarnold
- Top Notch Member
- Posts: 334
- Joined: Sat Jan 04, 2014 7:28 am
- My tercel:: 1983 SR5 4x4 with a tummy tuck and a nose job and now a pace maker!
- Location: jordache ,ca
carb adjustment is skrewed
I used to laugh at the man with a pinto 
, until I became a humble servicer of a tercel 
, until I became a humble servicer of a tercel -
smokerx
- Member
- Posts: 36
- Joined: Mon Jun 27, 2011 9:54 pm
- My tercel:: 1983 SR5 wagon 4WD stock 3A-C Federal
Re: carb adjustment is skrewed
My manual's final mix table says 1981-1983 Canadian 3A. Then gives a separate table for U.S. 1981-1983 3A-C. Unless it's a Canadian we'll assume you have a 1983 3A-C. to make sure, match it to the Emission control systems diagrams in the back of the fuel and exhaust system section in the pdf. manual available here.
Preset Idle mix specs: (number of turns counterclockwise from seated position=turned clockwise until mix screw contacts seat):
1983 3A...............2 and 1/2 turns
1983 3A-C federal and Cali models...........2 5/8 turns
WITH ENGINE AT NORMAL TEMP,RADIATOR FAN OFF AND AIR CLEANER INSTALLED
step1: turn mix screw to obtain fastest possible idle.
step2: turn idle speed screw to 700 RPM for 3AC & 3A engines
step3: Repeat those steps until step1 will not yield a faster idle
Step4: on 1983 cars turn the mix screw clockwise to obtain an idle of 650RPM
Step5: set final Idle speed for 1981-1983 US and Canadian cars 3A-C to
4 speed manual: 550 RPM
5 or 6 speed manual no power steering: 650 RPM
5-6 manual with pwr steering: 800 RPM
auto trans no pwr steering: 800 RPM
auto trans with pwr steering: 900 RPM
There's no tables for US models with 3A in this table; only Canadians 3A. IF your idle mix screw is easily accessible and visible. The carb is earlier than 1981 and dismiss the above tables. If its buried in a hole you can't get to, the process above should help. I use a short screwdriver bit,wrap a piece of duck tape around the chucking tip so it jams into the not opened end of a 1/4 inch opened end wrench to adjust the mix screw while an assistant lifts the air filter high enough so I can get in there, with the air filter lines still installed.
Preset Idle mix specs: (number of turns counterclockwise from seated position=turned clockwise until mix screw contacts seat):
1983 3A...............2 and 1/2 turns
1983 3A-C federal and Cali models...........2 5/8 turns
WITH ENGINE AT NORMAL TEMP,RADIATOR FAN OFF AND AIR CLEANER INSTALLED
step1: turn mix screw to obtain fastest possible idle.
step2: turn idle speed screw to 700 RPM for 3AC & 3A engines
step3: Repeat those steps until step1 will not yield a faster idle
Step4: on 1983 cars turn the mix screw clockwise to obtain an idle of 650RPM
Step5: set final Idle speed for 1981-1983 US and Canadian cars 3A-C to
4 speed manual: 550 RPM
5 or 6 speed manual no power steering: 650 RPM
5-6 manual with pwr steering: 800 RPM
auto trans no pwr steering: 800 RPM
auto trans with pwr steering: 900 RPM
There's no tables for US models with 3A in this table; only Canadians 3A. IF your idle mix screw is easily accessible and visible. The carb is earlier than 1981 and dismiss the above tables. If its buried in a hole you can't get to, the process above should help. I use a short screwdriver bit,wrap a piece of duck tape around the chucking tip so it jams into the not opened end of a 1/4 inch opened end wrench to adjust the mix screw while an assistant lifts the air filter high enough so I can get in there, with the air filter lines still installed.