Carb tuning and frustration...
- Thread starter gregnash
- Start date
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- carburetor
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NeverGiveUpYota
Dare me.
I pay attention about 1/2 the time. 
LAMBCRUSHER
SILVER Star
While truck is OFF...
- set idle mix screw to
- set idle speed screw so that the screw is just touching the plate///just BARELY
While truck is ON..
- set idle speed to desired idle speed///about 450-500
- set timing to new spot (so doing this based on the FSM, this includes disconnecting BOTH vac advance ports) at 7* (the bb)
- adjust mixture screw for max vacuum, highest idle speed
- set timing to 7*
- set idle speed to about 600
- set timing to 7*
- adjust mixture screw for max vacuum, highest idle speed
- set timing to 7*
- set idle speed to 650
- set timing to 7*
now it's running fat (rich idle) but we're sure the throttle plate won't interfere with the mixture setting and we're ready to LEAN DROP.
- turn idle mix screw IN SLOWLY till the idle DROPS...(turn, wait, listen; turn, wait, listen; repeat...)
- once idle drops , you're just lean
- back the mix screw out a quarter to half a turn
- set timing to 7*
- set idle speed to 650
- set timing to 7*
- set idle speed to 650
- set fast idle to whatever...
I like to drop the idle LOW after setting it all to let it chug a bit. if it doesn't keep running down low, something still ain't right.
I like to ramp up my idle speed slowly during initial baseline to rich idle so the throttle plate setting can't influence the mixture setting- if you set speed before mix, and open the plate too far to compensate for an unknown lean issue(screw in too far- some carbs want 4 turns; mine did), then you'll never get the mix screw to do anything as you will have mistakenly bypassed the idle circuit, which is where the mix screw does its work.
clear as mud??? hope this helps-
NeverGiveUpYota
Dare me.
Ok call me an idiot whatever... to start the truck the choke has to be pulled or to get it to run w/ the idle speed barely touching would be a feat of magic. Yes/no? I'm being 100% serious w/ an undertone of sarcasm.
And to set timing I was under the idea truck needs to be warm? So start truck, use feat of magic to get truck w/ choke pulled to slowly be off choke down to 500 rpms. Yes/no?
Then shut off truck and hook up timing light. Start again hoping it will start and run w/o choke at 500 rpms then set timing. Let gun sit attached now? And go back to carb and play w/ idle mix and idle speed again.
This is what boggles me everytime. I read it and obviously I had a crack manifold so maybe this will be a whole different scenario once it's welded up. So no, not clear as mud especially seeing that mud ain't clear.
And to set timing I was under the idea truck needs to be warm? So start truck, use feat of magic to get truck w/ choke pulled to slowly be off choke down to 500 rpms. Yes/no?
Then shut off truck and hook up timing light. Start again hoping it will start and run w/o choke at 500 rpms then set timing. Let gun sit attached now? And go back to carb and play w/ idle mix and idle speed again.
This is what boggles me everytime. I read it and obviously I had a crack manifold so maybe this will be a whole different scenario once it's welded up. So no, not clear as mud especially seeing that mud ain't clear.
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NeverGiveUpYota
Dare me.
What I didn't say @LAMBCRUSHER is I really appreciate your explainations and how you type them up so folks like me and break it down better in our heads... I just don't get how you get the truck OFF choke w/ the idle speed barely touching the plate. Furthermore at 500 rpms w/ the idle speed barely touching as well.
LAMBCRUSHER
SILVER Star
I guess I assumed a guy had had his truck faking an idle enough to get warm...you may have to start off somewhere. get it close and warm up the truck. shut it down and set lean drop. a truck without vacuum leaks will idle at about 200 rpms. not pretty sounding, or strong, but running. if you set the idle speed too high to start, you bypass the idle circuit, making the mixture screw useless...I suppose it's a bit of chicken or egg, but then, do you set timing first, or idle speed? the trick I'm highlighting is to set up rich idle so it can drop lean. it needs to be done in baby steps. check out this thread> Cruiser Carb Info - Land Cruiser Tech from IH8MUD.com at the bottom, he outlines the lean drop from cold.....I have added steps to help my own handicap.
4Cruisers
SILVER Star
An even better solution (from a long-term life-cycle perspective) would be to permanently install a rigid tube through the air cleaner housing, assuming the alignment doesn't interfere with the filter element (I haven't checked this out on my '76 FJ40 or '84 FJ60 yet), so that you can run a long-bladed screwdriver through at the proper angle. That way no removing/reinstalling of plugs in the housing would be needed every time you needed to adjust the screw.
I noticed recently, in more than several instances during my '86 FJ60 build, that Toyota purposely added bolt/screw access features to body sheet metal. This fix would be an extension of that philosophy.
NeverGiveUpYota
Dare me.
Yea I saw your mention of this elsewhere. Pretty ingenious and total redneck move. I like it but sure as heck don't want to go drilling holes into my air cleaner housing.
Another person added a pix of a long flathead bit w/ a rubber cap on the end for the idle mix screw. I liked that idea better and far easier for me to put together.
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NeverGiveUpYota
Dare me.
Thanks I appreciate your honest comment. But again, 'faking an idle' ?? Meaning off choke correct? And honestly 200 rpms? A nearly 30 year old truck, hmm. When I get mine all back together I'll be very curious to see if mine would idle that low.
gregnash
Anal Retentive Analyst
- Thread starter
- #90
I dont know about 200rpm holding the idle but the 500rpm yes. I have had her where she ran horribly at 500rpm but still was able to idle herself up a small hill (when I first got her and was trying to figure everything out). That is one of the things that I love the most about this old tractor motor.
Thankfully it is supposed to warm up this week and then cool off a little later, mid to high 50s as a high!! YEAH!! Also another member has offered me his spare carb as a loaner until I get mine figured out. This will serve two purposes, 1) to allow me to rebuild my carb AGAIN, and 2) to see if it truly is a carb issue or something else.
Thankfully it is supposed to warm up this week and then cool off a little later, mid to high 50s as a high!! YEAH!! Also another member has offered me his spare carb as a loaner until I get mine figured out. This will serve two purposes, 1) to allow me to rebuild my carb AGAIN, and 2) to see if it truly is a carb issue or something else.
NeverGiveUpYota
Dare me.
Sounds good. Really eyeball all the linkages and plates and brackets well from the photos on SOR. They are a huge help.
And yes we're getting a few days of 50's too but w/ rain. Oh well. Soon enough it will be real wrenching weather again.
gregnash
Anal Retentive Analyst
- Thread starter
- #92
Yup that is the plan plus posting pictures here to see if anyone notices a smoking gub.
And @Output Shaft There may be a partial linkage issue in there as I DO have the ability to pull on the pedal with my toe and drop the idle. Remembered to test that on my way to work this morning and was able to consistently replicate that.. So that means that the spring is dead and not pulling the linkage back to it starting spot, Which would be until the adjust screw hits the linkage adjuster plate right? Or could possibly mean that there is other areas sticking. When I get the loaner carb I am going to purchase a new rebuild kit and rebuild MY carb again plus grab an OEM AC plunger from City Racer. OEM Accelerator Pump Plunger for '79 to '87 Land Cruiser FJ40 FJ60
I plan to do this just in case I missed something and also take care of some other known issues like my secondary diaphragm not opening and my slow cut secondary leaking.
NeverGiveUpYota
Dare me.
You can get a plunger straight from toyota... that's who I got mine from. Not that expensive.
gregnash
Anal Retentive Analyst
- Thread starter
- #94
I will check with Onur but thought he recently (like within the last month) said there were no more stateside and no ETA on more. Could be wrong though. Need to put in an order with him anyways as the wife needs new cupholders for the 4Runner and I need a couple other things.
NeverGiveUpYota
Dare me.
Idk but I'd call w/ the part number anyway. Unless one isn't local to you. For me it's the cheaper route.
It's cool someone is lending you a carb. I know I'm in no place to be shelling out $300 plus on a rebuilt carb right now. Understandably folks do that work for a living but personally friend to friend... it's better to offer things cheaper... we're all in the same place here. We love our trucks and cruiser karma is just as real as karma in any other situation.
It's cool someone is lending you a carb. I know I'm in no place to be shelling out $300 plus on a rebuilt carb right now. Understandably folks do that work for a living but personally friend to friend... it's better to offer things cheaper... we're all in the same place here. We love our trucks and cruiser karma is just as real as karma in any other situation.
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CuCruiser
SILVER Star
Got that video ready yet!?
I kid.
I kid.
When I get a chance this week, I'll ship out that carb via USPS to you.
Lets get these issues sorted out!
Lets get these issues sorted out!
NeverGiveUpYota
Dare me.
I say ship him a 6 of something local.
Alex is a good guy!
Mine came with one of those air cleaner housings that sits off to the front left. I wish I'da had that on my first 60 years ago. I'm not sure where you get the parts, but if I was to do a carb 60 with a desmog, I would definitely swap to the side mount air cleaner housing, it is sooooooo easy to fxxx with the carb that way.
Just a suggestion for you carb lovers out there.
Just a suggestion for you carb lovers out there.
