First carb rebuild...hard earned success (1 Viewer)

[FJ Noob]

This is on a 1987 stock 2F...short story, died taking off from a light when I gave it gas in 1st. Acted like fuel line problem. Eventually got home by keeping higher RPM (1800 & up).

Got home and saw fuel leaking at the carburetor.

Here...

Backed out for reference...

Cruiser’s are new to me as are carburetors.

Just putting this out there while I dive into the FSM

 

[Spike Strip]

Mr. Toyota calls that a 'Secondary Slow Cut Valve" Long NLA from anywhere and it's not serviceable.

Unless it's really gushing bad prolly not the reason for stalling, but could be. Common to leak, so should be fixed.

Common repair is to remove that plunger, cut off the arm, and use a short 8mm bolt and JB weld in to block the passage.

You could also send the carb to a MUD guru rebuilder to have it rebuilt and repaired. Or, if you don't need smog equip, you could replace the carb entirely with a City Racer clone or even New Non-USA Toyota Carburetor.

And of course, someone will quickly also chime in about Fuel Injection but that's not my thing... I like carbs!

 

[OSS]

Secondary slow cut valve. They all leak a bit now. Shouldn't be dripping gas though.

search "secondary slow cut" on this forum. Lots of info

 

[FJ Noob]

Mr. Toyota calls that a 'Secondary Slow Cut Valve"

Secondary slow cut valve. They all leak a bit now. Shouldn't be dripping gas though.

search "secondary slow cut" on this forum. Lots of info

Spike...thanks for id'ing the part.

OSS...thanks for the lead.

So, after doing a search I see the modification. From that, it also looks like I'm missing some parts that would actuate the SSCV if left in original configuration.

Also sounds like, with no mod, without the SSCV actuating it could cause fuel starvation going from idle RPMs to "driving" RPMs.

If the SSV is just coincidental, any other ideas what would suddenly cause a low RPM fuel starvation situation? Pump seems to be working ok...or at least there is fuel consistently making it's way into the fuel filter.

 

[Dr. John]

Sounds like the carb's accelerator pump has failed. The stock Aisin leather one is best. Most rebuild kits have rubber ones that don't last. They can be replaced without removing carb.

 

[Spike Strip]

Troubleshooting Secondary Slow Cut Valve Modification on Aisin 2F Carb

Hey Folks, I'm looking for suggestions on how I might go about diagnosing whether or not the modification I did to the Secondary Slow Cut Valve (see image below) is working correctly. This is on a OEM Aisin Carb (PN 21100-61141) from a 2F 12/1981 FJ60 USA. After having successfully rebuilt...

forum.ih8mud.com

 

[FJ Noob]

Troubleshooting Secondary Slow Cut Valve Modification on Aisin 2F Carb

Hey Folks, I'm looking for suggestions on how I might go about diagnosing whether or not the modification I did to the Secondary Slow Cut Valve (see image below) is working correctly. This is on a OEM Aisin Carb (PN 21100-61141) from a 2F 12/1981 FJ60 USA. After having successfully rebuilt...

forum.ih8mud.com

Yep, read through and got the best understanding from that. As I think more, the SSCV shouldn’t have anything to do with dying out at idle...right?

 

[OSS]

try easy cheap things first. Replace the fuel filter & reassess

 

[FJ Noob]

If there’s a rubber one in there and the PO was running mostly 10% ethanol, would that make it deteriorate faster?

 

[Spike Strip]

First check your ICS (Idle Control Solenoid) - The thing with the wires going to it. With Key On Engine Off, tap the halves of the green connector together and listen for a 'Click-Click-Click' if yes, move on. If no, then check for 12v to connector (Green wire side).

Also, what OSS says is easy to try first. Use the Toyota OE Fuel filter. It's the best available.

 

[FJ Noob]

try easy cheap things first. Replace the fuel filter & reassess

Brand new OEM fuel filter got put in last week

 

[FJ Noob]

So...ran over to my donor truck and looked at the carb. Looks like it has a complete SSCV “assembly”.

Going to run through the diagnostics you guys mentioned while the carb is still on first.

Worst case is swap carbs and go from there.

Fired the truck up right away with 3/4 choke and it’s a bit more than a little leakage...that’s about a tablespoon after about a min.

Also found this...what would someone do this? Vac line plugged and where it should attach.

 

[Spike Strip]

Can't exactly tell from the pic but looks like they disabled the EGR (perhaps to stop a stumble?) ...

Either way, if you're putting on a carb that's 35 years on, needs rebuild for RFG compatibility and clean out the schmutz.

 

[FJ Noob]

First check your ICS (Idle Control Solenoid)

It clicks...moving on.

 

[FJ Noob]

Can't exactly tell from the pic but looks like they disabled the EGR (perhaps to stop a stumble?) ...

Either way, if you're putting on a carb that's 35 years on, needs rebuild for RFG compatibility and clean out the schmutz.

Talked to Previous PO the other night (he sold it a year ago). Said the carb was “newer”.

If my current SSCV is leaking that much....with piston in the closed position, think it may be enough to starve it at idle?

Excuse my ignorance...RFG? ****EDIT**** Haven't been using RFG. The engine feels/sounds MUCH better with non-ethanol so I have been using that.

 

[Spike Strip]

SSCV is seperate from the Idle Circuit. As stated, if it dies when you press the pedal, could be Accel pump or Power Valve, or could be dirt...

If the other carb is vaguely 'newer' swap that on and go, if you don't want to do a rebuild...

 

[NeverGiveUpYota]

If there’s a rubber one in there and the PO was running mostly 10% ethanol, would that make it deteriorate faster?

Per if your asking about the accelerator pump... as @Dr. John mentions, the rubber on the acc pump is prone to just stick whereas the leather one slides better. When replacing its wise to soak the new one (you can get from the dealer (~$20) or from o’riellys. Both have the leather one tho aftermarket comes in a whole carb rebuild kit for $40.... in oil for a few hours before installation. You don’t need to pull the whole carb to change it out.

 

[FJ Noob]

SSCV is seperate from the Idle Circuit. As stated, if it dies when you press the pedal, could be Accel pump or Power Valve, or could be dirt...

If the other carb is vaguely 'newer' swap that on and go, if you don't want to do a rebuild...

Yeah...as I talk it out, the SSCV doesn’t make sense.

I think I found a better starting point...

The boot over the pump plunger is falling apart and quite a bit of gas is coming out. It’s flowing across a plate under the carb and towards the bottom of the SSCV, making it look like it’s leaking more than it is.

Since I’m guessing the boot isn’t the only thing making a seal on the plunger, it’s a sign that other seals have probably gone out?

Looks like it’s definitely time for a carb rebuild?

I may pull and try the other one just to get this truck running while the original gets rebuilt. If not, I’m kind screwed come work time on a Monday .

Never rebuilt a carb before...should I give it a try or send it off?!? I’ll start searching MUD, but who are the carb gurus?

 

[NeverGiveUpYota]

Yeah...as I talk it out, the SSCV doesn’t make sense.

I think I found a better starting point...
View attachment 2123607

The boot over the pump plunger is falling apart and quite a bit of gas is coming out. It’s flowing across a plate under the carb and towards the bottom of the SSCV, making it look like it’s leaking more than it is.

Since I’m guessing the boot isn’t the only thing making a seal on the plunger, it’s a sign that other seals have probably gone out?

Looks like it’s definitely time for a carb rebuild?

I may pull and try the other one just to get this truck running while the original gets rebuilt. If not, I’m kind screwed come work time on a Monday .

Never rebuilt a carb before...should I give it a try or send it off?!? I’ll start searching MUD, but who are the carb gurus?

Edited. Yes, as I wrote you can replace that part w/ a carb rebuild kit.... not terribly hard to do yourself.
JimC does them but there are others outside of mud that do them too. All depends on time, money and how set on mud you are... I have one non mud name in my signature. Flip your phone sideways and it will be revealed.

 

[FJ Noob]

Sounds like the carb's accelerator pump has failed. The stock Aisin leather one is best. Most rebuild kits have rubber ones that don't last. They can be replaced without removing carb.

Dr...is this the part you're talking about? Specifically, the seal inside on the end of the rod. I'm envisioning something like the pumps on old Coleman lanterns or stoves...about right?