aisin carburator

[1978freebornred]

background:
runs on 1/4 choke, white smoke from too much fuel, sight glass is showing more than half full, flooding with fuel overnight,

the idle misture screw is that on the side between the carb and the valve cover on my 78? would that make it flood? the float is a possible culprit but i doubt it idk cause it was flooding when parked over night flooded so bad i currently have the fuel line vise gripped. So i have a productive day and can drive it more than in my driveway what would experience say?

 

[crumbo]

you got in/out/ return fuel pump?
second barrel vaccuum broke?

 

[ClemsonCruiser]

The idle mixture screw isn't the source of your flooding, the float though is a possibility. Also could your fuel return line be clogged? You say you are getting white smoke?? Did you mean black smoke? As white smoke is an indication of water/antifreeze in the combustion chamber not running rich. Additionally if it will only run with 1/4 choke could be the indication of a vaccum leak somewhere.

All that said I am no carb. guru but most likely if this carb. has been sitting for a while it could benifit from a rebuild....

 

[Pighead]

If my float bowl was overfilling, I'd probably take a look at the needle valve and the float...

 

[1978freebornred]

what does the idle mixture screw do then? and it only has 1 fuel line to the carb stock fuel pump, as the vapor line really gets it flooding so its capped off. yes white gray smoke as oil is dripping from tail pipe, my head and antifreeze is fine if it wasnt this would become a fuel injected 2fe or whatever or 350 cruiser whichever would be cheaper. anyway... oil was dripping from tail pipe until i vise gripped the fuel line so it cant flood.

 

[ClemsonCruiser]

what does the idle mixture screw do then? and it only has 1 fuel line to the carb stock fuel pump, as the vapor line really gets it flooding so its capped off. yes white gray smoke as oil is dripping from tail pipe, my head and antifreeze is fine if it wasnt this would become a fuel injected 2fe or whatever or 350 cruiser whichever would be cheaper. anyway... oil was dripping from tail pipe until i vise gripped the fuel line so it cant flood.

The idle screw only effects the idle speed, it does this by allowing more or less air into the carb. I am pretty sure you need a fuel return line on a '78 and that is most likely the source of your flooding issues.

 

[broth9640]

Not sure about the return line since my cruiser asin carb knowledge is weak, but I had a similar problem with a different carb and it turned out to be my float. It was leaking and taking on fuel . So the needle valve wouldn't close until it was overfilled . X2 on checking that and the needle valve .

 

[1978freebornred]

return line is for sure not it cause it ran great for 2 years without one... a return line would be great and all but i dont have a charcoal canister or fuel seperator or vented cap so basically when i had it hooked up for 2 months it caused more trouble than help. im checking the float and needle seat in about 15 min from this post.

 

[subzali]

A fuel return line is nice, but not necessary, as earlier Aisan carbs did not have one. It helps with vapor lock issues. On a '78 it doesn't return to the pump (like on the FJ60s) but returns directly to the tank. In the picture above you have the fuel return line connected to the carb, but it sounds like you have it blocked off somewhere downstream.

Your charcoal canister/EVAP system is different from anything being discussed here at the moment.

I tried going back through a couple of your other threads to see where you've come to get to this point - as I remembered it's been a pretty frustrating road.
https://forum.ih8mud.com/40-55-series-tech/527410-40-not-running.html

https://forum.ih8mud.com/40-55-series-tech/526059-carb-rebuild.html

Anyway, if the engine will only run with the choke applied that often means you're getting too much air into the intake. Which means you're likely to have a vacuum leak. Have you checked for vacuum leaks? What kind of vacuum reading are you getting?

There are several screws on your carb, do you have a good reference of which is which? You are right that the idle mixture screw is on the side against the valve cover, and this screw meters in fuel through the idle circuit. If this screw is turned all the way in then no fuel can flow through the idle circuit and your engine should die. If it doesn't that means it's getting fuel from elsewhere. This can happen if you have your idle speed screw (elsewhere on the carb) too high, which keeps the throttle plate open just a tad. Closing the choke plate also does this by engaging the high idle screw at the same time.

Also, have you checked that your idle circuit solenoid (ICS) is connected with switched 12V power and operates properly?

If your ICS is working properly and you have no vacuum leaks, do the lean-drop method of adjusting the carb (you can search for carb adjustment procedures on this site), and see if that helps.

By the way, what do you mean by vise-grip the fuel line? It's metal, so if you vice-grip it it will crush it and you won't be able to get it open again.

 

[Splangy]

what does the idle mixture screw do then? and it only has 1 fuel line to the carb stock fuel pump, as the vapor line really gets it flooding so its capped off. yes white gray smoke as oil is dripping from tail pipe, my head and antifreeze is fine if it wasnt this would become a fuel injected 2fe or whatever or 350 cruiser whichever would be cheaper. anyway... oil was dripping from tail pipe until i vise gripped the fuel line so it cant flood.

The idle mixture screw alters the idle mixture. It affects only the IDLE mixture, not higher RPMS.

Why would oil drip from the tailpipe if it was flooding?

Do you see fuel dumping out of the bowl vents and into the venturis when it's running? (Or did you before vice-gripping the fuel line?).

 

[65swb45]

Do you see fuel dumping out of the bowl vents and into the venturis when it's running? (Or did you before vice-gripping the fuel line?).

THAT is the most relevant question at this point.

If you can pull one of the jet access plugs on the front of the carb, drain the bowl, and then watch the bowl refill and overflow thru the vents, you've got a needle/seat issue or a float issue.

And if pinching a fuel line REALLY does anything, I'd double check vapor pressure in the fuel tank by removing the gas cap.

Best

Mark A.

 

[shelfboy1]

if its flooding that bad you may want to check the oil.the excess fuel has probably thinned it out ,but fix the problem first.

 

[FJ40Jim]

Problems visible in 1st picture:
1. HIC hose is connected directly to manifold fitting in front of carb (HIC valve is missing). This a vacuum leak into the front runners of the manifold. Remove hose, cap fittings.
2. ICS wire is not connected. It needs plugged in to a 12V power supply to idle.
3. Hose for CB is in OOP clip for HIC hose, connected to who knows what. Connect CB to manifold vac.
4. Choke cable is improperly positioned in clamp. Chrome thimble on end goes in clamp, then adjust inner cable for full choke opening when knob is pushed in fully.

Edit: biggest problem: installed Aisin carburetor. Aisin makes feewheel hubs and transfer cases. They don't know nuthin' about fuel systems. Recommend installing Aisan carb. They make good fuel related parts.

 

[duffontap]

Edit: biggest problem: installed Aisin carburetor. Aisin makes feewheel hubs and transfer cases. They don't know nuthin' about fuel systems. Recommend installing Aisan carb. They make good fuel related parts.

Jim for the win.

 

[65swb45]

Problems visible in 1st picture:
1. HIC hose is connected directly to manifold fitting in front of carb (HIC valve is missing). This a vacuum leak into the front runners of the manifold. Remove hose, cap fittings.
2. ICS wire is not connected. It needs plugged in to a 12V power supply to idle.
3. Hose for CB is in OOP clip for HIC hose, connected to who knows what. Connect CB to manifold vac.
4. Choke cable is improperly positioned in clamp. Chrome thimble on end goes in clamp, then adjust inner cable for full choke opening when knob is pushed in fully.
5. Bolt on accel pump arm looks like it's about to fall off!
Edit: biggest problem: installed Aisin carburetor. Aisin makes feewheel hubs and transfer cases. They don't know nuthin' about fuel systems. Recommend installing Aisan carb. They make good fuel related parts.

Fixed.

 

[1978freebornred]

ok theres rubber 3/8 hose to the fuel pump that is vice gripped because it was flooding the whole engine so bad that it went throught 6 gal of gas... thats how oil was dripping from the tail pipe my exhaust manifold and sparkplugs... the vise grips are on the supply line so that fuel from the tank dosent keep pouring out when its not running because i changed the oil, the solenoid has never been hooked up in 2 yrs and ran fine without it so it probably should be hooked up but not the worst problem which is venturi leaking like a sive. it will now run after some idle adjustment and manifold gasket without choke but still dies now when i let off the gas when driving... so as of now the problem is dieing after i let of the gas when driving and sputtering when i let off the gas when driving. the accel pump bolt is junk but is there tight with tfe paste but as for a vacum leak i sprayed carb cleaner looking for one around the seams of the carb and put some high temp black silcone where it leaked also replaced the manifold gasket as it leaked and sealed up the exhaust horn cause it was leaking where the end part comes off...

what its doing now
1 dieing/sputtering while driving when i let off the gas
2 still idling a bit rough but i can adjust that
3 i dont beleive it is still leaking at venturis when it is turned off but just to be safe i still vise gripped it

To do list so far
cap off HIC hose
run over power line to solenoid hopefully it clicks but dont know
find out about number 3 on the list

 

[My71FJ40]

OR....make life easier and buy a new carb, trollhole carb, Aisan...good luck.

 

[1978freebornred]

well thatd be easy and ive thought of that, i dont think trollhole would do it for 50 bucks... so ill have to suffer through it.

 

[edwjmcgrath]

If it idles without idle solenoid, you have adjusted it so that you aren't using the idle circuit.
Connect the solenoid. Set the idle mixture screw to 2-3 turns out from all the way in. Then adjust the idle speed and mixture to spec. This all assumes that you have solved the fuel overflow problem.

 

[Splangy]

the solenoid has never been hooked up in 2 yrs and ran fine without it so it probably should be hooked up but not the worst problem which is venturi leaking like a sive.

It did not run fine without the solenoid hooked up. You may have thought it did, but it did not. You probably had the idle up around 1000rpm (which is not an idle) to compensate for it.
If the venturi's are dumping fuel at idle, it's not idleing. You're compensating for it by cranking up the idle screw. Hook the idle solenoid back up and then try to get it idleing.

Are you sure the fuel is actually coming out of the venturis, or is it coming from the bowl vents?

You seem to have a plethora of problems working against you. Unforunately, it looks like somebodys been tinkerin' with that there carburetor and it's gonna take some work to get it runnin' right again. Just fix all the problems that have been pointed out to you and take it from there.