FJ40 Carb issue--rich at idle

[FJ40Jim]

The distributor is a late 1960's style. vacuum advance w/ pertronix added.
Carb is 1970 US-spec, later replacement.
All good stuff.

The vac hose should not be connected to the dissy. The port on the carb is decel fuel cut, not ported dissy vac.

For now, remove the vac hose, cap the fitting on the carb and set base timing to 12 degrees @600rpm.

 

[Shes Mad]

Thanks for the input. Should the vac lines be switched, or just do as you say, ie i don't need vac advance.

 

[subzali]

It did not look to me like your carb has provisions for vac advance. There is no ported vacuum connection on your carb. Mark and Jim (or you, with the right measurements/technique) could drill one, however. I believe your advance will come mechanically.

 

[FJ40Jim]

Should the vac lines be switched?

No. There is no ported vac fitting on the carb, so no way to power the vac advance.

or just do as you say, ie i don't need vac advance.

It's not that vac advance is unneeded. There is no port on the carb to connect to the dissy. So for the time being it will have to operate as a centrifugal advance only distributor.

 

[softdrinkviking]

altitude

Except if you're at altitude, which can drop that number down to the 12-13 range (in Denver for instance).

The user manual for my Allstate vacuum gauge states that you should take off one inch of pressure for every thousand feet above sea level.

 

[Shes Mad]

The distributor is a late 1960's style. vacuum advance w/ pertronix added.
Carb is 1970 US-spec, later replacement.
All good stuff.

The vac hose should not be connected to the dissy. The port on the carb is decel fuel cut, not ported dissy vac.

For now, remove the vac hose, cap the fitting on the carb and set base timing to 12 degrees @600rpm.

What should be connected to the decel fuel cut port. I did get it running better, but I am still getting popping out the exhaust on decel, which I assume is unburnt fuel

 

[Shes Mad]

Anybody? The port has vac, so I plugged it, but I would like to get the port routed to the correct place

 

[subzali]

Unless you have the VSV for your model year for that port to connect to, I think it should be plugged as Jim recommends.

 

[Shes Mad]

I dont, not even sure I know what it is, or where it is. Can you post a pic? Might have something in my spares pile

 

[subzali]

Check the SOR diagrams:
Specter Off-Road Land Cruiser Parts - Page 048 Land Cruiser Emission Controls

 

[FJ40Jim]

Cap it. The decel vac port is useless without the computer & switching valve.

Popping in the exhaust is unburnt fuel AND air. There's not an easy fix for unburnt fuel on overrun, but the air is usually present in the exhaust from an exhaust leak. Make sure manifold gasket, downpipe gasket, etc is perfectly sealed.

 

[Shes Mad]

got it. I did take it in for a new exhaust. It was only 6 months old, but the muffler was cracked-probably from backfire. Got it fixed.

It's running a lot better now. I was able to get the idle down so that it was drawing off the idle port (no fuel running in the carb. It is at 600 RPM now.

Thanks for all your help

 

[Nhirsch]

Hi, I know it's an old thread but...
I rebuild my 1982 fj40 aisin carb and now I have a weird problem: the mixture screw works wrongly - when fully closed rpm is increasing instead of shutting down the engine.

I'm trying to debug it and have some questions:
1. Is the shutdown solenoid suppose to close vacuum or fuel circuit?
2. From what I see, the mixture screw close the passage to the hole below the throttle plate. The question is if mixture screw control the amount of vacuum/air on this circuit or amount of fuel?

I took the carb apart 2 times already and re-checked all passages clearance and components but can't find the reason.

Another note, I have a new Chinese carb which works well on same setup (manifold, insulator etc.) So I believe the problem is on my rebuild....

Thanks

 

[Nhirsch]

Hi, I know it's an old thread but...
I rebuild my 1982 fj40 aisin carb and now I have a weird problem: the mixture screw works wrongly - when fully closed rpm is increasing instead of shutting down the engine.

I'm trying to debug it and have some questions:
1. Is the shutdown solenoid suppose to close vacuum or fuel circuit?
2. From what I see, the mixture screw close the passage to the hole below the throttle plate. The question is if mixture screw control the amount of vacuum/air on this circuit or amount of fuel?

I took the carb apart 2 times already and re-checked all passages clearance and components but can't find the reason.

Another note, I have a new Chinese carb which works well on same setup (manifold, insulator etc.) So I believe the problem is on my rebuild....

Thanks

Another clue - when disconnect the solenoid engine doesn't stop (solenoid is working fine - tried with a new one as well)

 

[Nhirsch]

Hi, I know it's an old thread but...
I rebuild my 1982 fj40 aisin carb and now I have a weird problem: the mixture screw works wrongly - when fully closed rpm is increasing instead of shutting down the engine.

I'm trying to debug it and have some questions:
1. Is the shutdown solenoid suppose to close vacuum or fuel circuit?
2. From what I see, the mixture screw close the passage to the hole below the throttle plate. The question is if mixture screw control the amount of vacuum/air on this circuit or amount of fuel?

I took the carb apart 2 times already and re-checked all passages clearance and components but can't find the reason.

Another note, I have a new Chinese carb which works well on same setup (manifold, insulator etc.) So I believe the problem is on my rebuild....

Thanks

Another clue - when disconnect the solenoid engine doesn't stop (solenoid is working fine - tried with a new one as well

 

[Nhirsch]

I re-checked all passages clearance and also cleaned a weird jet on the carb cover which sits in front of the primary slow jet. Does anyone know what is this jet and what's the size suppose to be?

 

[Nhirsch]

This jet doesn't appear on the carb diagram....

 

[Nhirsch]

BTW- vacuum is around 18 and no leaks on manifold.

 

[Nhirsch]

I realized that the idle circuit is too rich. I read that normally on carbs, idle circuit should have an air bleeder for mixture of fuel/air. Anyone knows where air suppose to come from, to idle circuit?
Thanks in advance.

 

[Nhirsch]

Is this the idle air bleeder?