1979 Truck 20R carb tuning help? - YotaTech Forums


Go Back   >


Pre 84 Trucks 1st gen pickups

1979 Truck 20R carb tuning help?

Reply
 
LinkBack Thread Tools Search this Thread
Old 07-16-2011, 01:46 PM   #1
Registered User
Thread Starter
 
the big d's Avatar
 
Join Date: Jun 2011
Location: Columbia County, GA
Posts: 36
1979 Truck 20R carb tuning help?

I have looked but cannot find the factory specs for the idle air mixture screw, I know it is running rich, but how much I do not know. It was 5 turns out from closed.
the big d is offline   Reply With Quote
Old 07-17-2011, 09:55 AM   #2
Registered User
Thread Starter
 
the big d's Avatar
 
Join Date: Jun 2011
Location: Columbia County, GA
Posts: 36
Is there a way to tune it?
the big d is offline   Reply With Quote
Old 07-23-2011, 09:14 PM   #3
Registered User
 
Join Date: Jul 2011
Posts: 12
bring it to a shop and get a tune up, sounds like you wouldn't know where to start lol
Yota1979 is offline   Reply With Quote
Old 02-05-2012, 05:34 PM   #4
Registered User
Thread Starter
 
the big d's Avatar
 
Join Date: Jun 2011
Location: Columbia County, GA
Posts: 36
Truck is tuned up. new plugs, wires, cap rotor, air filter fuel filter... everything that I can think of that can affect tuning... I was getting around 15mpg, now about 12mpg. Driving is 60 highway/40city, driven aggressively for the little truck. Nothing rebuilt... any specs? I cannot find them anywhere.
the big d is offline   Reply With Quote
Old 02-09-2012, 10:08 PM   #5
Registered User
 
Join Date: Nov 2010
Location: Portland, OR
Posts: 101
lean it out until it idles highest, then make it a little richer
ConSeann3ry is offline   Reply With Quote
Old 02-10-2012, 05:49 AM   #6
Registered User
iTrader: (2)
 
Lons81's Avatar
 
Join Date: Jan 2012
Location: Stepheville, TX
Posts: 334
Usually, turn the idle mixture screw in until it just bottoms out, the unscrew about 2 1/2 to 3 1/2 turns. Start engine and set the idle speed to around 750-800 rpm. Adjust the mixture screw in/out 1/2 turn to get smooth idle. I usually bump the throttle after each adjustment checking for smooth acceleration off idle.

You can download the FSM here http://www.ncttora.com/fsm/ Scroll down to the 79-85 section. There's a lot of info in this PDF file. Carb adjust is in the fuel section

Last edited by Lons81; 02-10-2012 at 06:22 AM.
Lons81 is offline   Reply With Quote
Old 02-10-2012, 10:11 AM   #7
Registered User
 
funcrazy1's Avatar
 
Join Date: Dec 2010
Location: Bellingham, WA
Posts: 112
Quote:
Originally Posted by Yota1979 View Post
bring it to a shop and get a tune up, sounds like you wouldn't know where to start lol
That is not very nice we are a helpful community my man
Quote:
Originally Posted by the big d View Post
I have looked but cannot find the factory specs for the idle air mixture screw, I know it is running rich, but how much I do not know. It was 5 turns out from closed.
Would this be a stock carb or a weber carb or asia carb?
funcrazy1 is offline   Reply With Quote
Old 02-10-2012, 12:11 PM   #8
Registered User
Thread Starter
 
the big d's Avatar
 
Join Date: Jun 2011
Location: Columbia County, GA
Posts: 36
The factory carb btw.
the big d is offline   Reply With Quote
Old 02-10-2012, 12:35 PM   #9
Registered User
 
nightstalker's Avatar
 
Join Date: Jan 2011
Location: newnan georgia
Posts: 288
5 turns out sounds extremly rich, any mods? i expect your plugs were looking black, most carbs, you will bottom out the air mixture screw(s) then start at 1 1/2 turns out, if doing by ear, i would do what was mentioned above by lons81. jmo
nightstalker is offline   Reply With Quote
Old 02-10-2012, 03:41 PM   #10
Registered User
Thread Starter
 
the big d's Avatar
 
Join Date: Jun 2011
Location: Columbia County, GA
Posts: 36
Stock engine, 360k or 460k miles. (Uncle can't remember how many times it rolled over)
the big d is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Why is Battery Leaking? bigblue82 General Electrical & Lighting Related Topics 10 07-06-2015 08:27 AM
Flowrate needed for Weber carb fuel pump kazuya2416 86-95 Trucks & 4Runners 3 06-27-2015 12:24 PM
Thinking about selling my rig SR5 PU dirtrider0129 Buying & Selling Advice - Feeler/Gauging Interest 10 06-24-2015 12:24 PM
Reese's 86 hilux paxanders 86-95 Trucks & 4Runners (Build-Up Section) 3 06-21-2015 06:29 AM
it runs! 94 First Responder 95.5-2004 Tacomas & 96-2002 4Runners 4 06-06-2002 02:19 PM


Tags
1979, 20r, 79, adjustment, back, carb, carburetor, chevy, columbia, hilux, idle, toyota, toytota, truck, tuning

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -8. The time now is 07:41 PM.


2010 InternetBrands, Inc.