86FJ60 leaking fuel at Carb (1 Viewer)

[Elbert]

Can someone tell me if there is any connection between modifing the exhaust and fuel leaking at the carb. I've not owned the truck for very long (couple of weeks)...what I can tell that has been done is that the egr vaccum hose is plugged, the converter no longer resided in the exhaust, the air pump is still there and apparently working?

When the exhust was modifed I've noticed that sometimes gas is leaking at the base of the carb, before exhaust work it was not leaking. I don't know if this is just considence or is there some connection.

I do plan on removing the smog crap.....since I don't have to deal with inspections where I live currently.

The leaking gas business cf course concerns me and I need to get that fixed. Its so nice that the carb bascially sits on top of of the hot exhaust manifold (right near it anyway)...

Truck seems to run fine.... after driving for a while I noticed the smell of raw gas and opened the hood to see that it looks like gas is leaking out of the drivers side of the bottom of the carb.

 

[jgordon]

First make sure the bolts holding the carb on are tight, if they're good, check the gasket between carb and intake manifold. I can't think of how they (exhaust and carb) would be interrelated. seems like the gasket between carb and manifold may have just given out.

 

[NocalFJ60]

Try and clean up around the carb and find out exactly where the gas is coming from. The fuel window on the front leaking? or the two bolts on either side of the window loose?

 

[60wag]

Or is the fuel leaking from the fuel line whre it connects to the carb? I doubt there is any connection to the exhaust work - a timely coinsedince.

 

[Elbert]

Well I have a nice picture of where its leaking but I've got to figure out how to reduce the size of the picuture before I post it. Anyway it looks like a small plunger and it on the drivers side at the base of the carb, it has two screws that connect it to the carb and on top is a little punger type rod that feeds off the throttle shaft....it appears that gas is leaking out of this..

I'll post a pic as soon as i figure out how to reduce the size...

Truck will idle all day without leaking.... once you drive it and give it pently of gas is when I've noticed it leaking.. Its only at the base.....not on the top or at the fuel line.

 

[soggy60]

Slow cut valve.

coincedence that it's leaking,,,,possibly banged while removing egr stuff...

can't be fixed, only replaced, about 50 bucks for the part.

did mine a few years ago.

Pete

 

[S&S1stCruzer]

Well I have a nice picture of where its leaking but I've got to figure out how to reduce the size of the picuture before I post it. Anyway it looks like a small plunger and it on the drivers side at the base of the carb, it has two screws that connect it to the carb and on top is a little punger type rod that feeds off the throttle shaft....it appears that gas is leaking out of this..

I'll post a pic as soon as i figure out how to reduce the size...

Truck will idle all day without leaking.... once you drive it and give it pently of gas is when I've noticed it leaking.. Its only at the base.....not on the top or at the fuel line.

Coincidence...maybe but I just had some headers installed, new cat and catback system from MAF and about 2 days later I start to smell gas within minutes of start up. I sent an email to the mechanic today but if you got somewhere with this please post pics and/or info thanks.

 

[Elbert]

S&S,

post your fix if have the time. I've got a picture of the item that's leaking I'll post a pic as soon as I can get the size of the picture reduced or I find another pic that works.

Mine is leaking at the base of the carb, driver's side, where there is a little plunger looking "valve" thats connected to the throttle linkage. As you give it more gas the throttle linkage engages this plunger, theough a mechanical arm.

of course a picture is more helpful...I'll try to do that later on this evening.

 

[Elbert]

ok there should be a pic attached to this post. See the small plunger looking thing at the base of the carb. What is this part called and what is involved in replacing it, also any sources? I've ordered a part through a local toyota dealer but they are not sure its the right thing, and its not come in yet.

 

[Elbert]

soggy you were right.... I'm told its called "secondary slow cut valve", I've ordered a part based on a faxed part list from a dealer....the parts guys did not know for sure what it was so I guess we'll see when it gets here. Price is about $130 now.... which is pretty expensive for this little part.

its just starting leaking by itself...I guess thats ok with a 20 year old part. But I've not gotten around to any EGR removal just yet. I'm trying to run down all the litlle things first and make sure I don't have other issues, before I tackle the EGR.

Truck will idle all day just fine, no leaks. At slow speeds no leask.... highway speeds are hard throttle....thats when it leaks. My assumption is that its has something to do with fuel deliverly, Yea I know...you don't have to be to bright to see that one...?

Anyone know what it does? Mine leaks gas at the present

 

[Elbert]

Ok for future reference that may help others. it was indeed the secondary slow cut valve and it was leaking gas from this valve (the rubber boot had split) on the side against the carb where you could not see it. I had a minor issue in removing the valve (one of the screws was in bad shape) but anyway it just unsscrewed and I replaced the vlave and gasket. If you ask me its a little expensive part...$130 range plus gasket about $5.

Next time I'll be calling cruiser dan... I guess to see what he can do. I had dealt with a place that I worked at before and did not even think to look into other sources at the time...guess I learned a little lesson.

Part #

Gasket 21641-38310
valve 21346-61140

none of the parts diagrams I found clearly references this part, I had the above mentioned dealer fax me a print screen and I took a wild guess at a poorly illustrated diagram. Maybe the above note will help someone else out.

 

[grant5127]

I take that little valve and throw it away & plug the holes in the carb base... just did one yesterday........

 

[FJ40Jim]

I take that little valve and throw it away & plug the holes in the carb base... just did one yesterday........

Though Grant has not noticed or doesen't care, it does make a noticeable difference. W/ the secondary slow circuit totally closed off, there is a stumble as the secondary opens, since there is no fuel flow initially.

A better application of Grant's technique is to break the arm off the valve and extract the plunger guts. Then thread a small stubby bolt into the plunger hole. Now the valve is always open inside, but cannot leak outside. IOW, the carb now works like any other non-smog unit.

That's another freebie, y'all can keep that.

 

[grant5127]

Never had a stumble issue... but at the same time I cut a couple of rounds off the secondary diaphragm spring & do some tweaking over on the linkage side .... I'm gonna try removing one today just strait-up & your way... Thanks

 

[Elbert]

Well I've got the same problem again. I've been smelling gas again and noticed it leaking fuel around the "new" valve. Got home this evening and opened hood to check it out...no leak. Left hood up for about 5 min and came back out side and gas is leaking out of the valve pretty good (engine off), I'll check the valve tomorrow to see if the rubber diaphram is broken, and I may try the modification suggested by Jim. Kind of wired that it would leak gas at the valve after the engine is off for a few minutes? Anyone experienced these type symptoms?

 

[Elbert]

Ok so I tried the modification as Jim suggested (removed the lever and contents of the valve, and then plugged the plunger hole at the top without restricting the holes at the bottom of the valve). Truck started up and idled fine...drove for a 20-30 miles at highway speed,and all of a sudden it woul dnot idle. Would really have to pump the gas at idle or maitain about 1500 rpm or truck would die. Sounds like running rich. I then tried the trick of grounding the fuel solonoid. Truck would idle to start with and after a few min of driving I would have the same problem. (will not maintain an idle at normal RPM). At full throttle trucks runs great///in fact better than it ever has, will accelerate a lot faster and rev higher through the rpm's.

I assume the little modificaitn to the cut valve has improved the gas flow through the carb, and it may be running to rich at idle? Truck is a half breed on the smog business. (no smog pump, eger valve disabled, no cat). Is there an easy fix beyond going back to a new cut valve. Seem like you would need to do that and or have the carb totally rebuilty and the rich / lean adjusted correctly. Any comments?

 

[beaufort-fj60]

I take that little valve and throw it away & plug the holes in the carb base... just did one yesterday........

Though Grant has not noticed or doesen't care, it does make a noticeable difference. W/ the secondary slow circuit totally closed off, there is a stumble as the secondary opens, since there is no fuel flow initially.

A better application of Grant's technique is to break the arm off the valve and extract the plunger guts. Then thread a small stubby bolt into the plunger hole. Now the valve is always open inside, but cannot leak outside. IOW, the carb now works like any other non-smog unit.

That's another freebie, y'all can keep that.

Never had a stumble issue... but at the same time I cut a couple of rounds off the secondary diaphragm spring & do some tweaking over on the linkage side .... I'm gonna try removing one today just strait-up & your way... Thanks

what exactly does the valve do?...

 

[beaufort-fj60]

well, this thread explains it pretty good... https://forum.ih8mud.com/60-series-wagons/130815-carb-leak.html

 

[FJ40Jim]

The secondary slow cut valve is normally closed, preventing the flow of fuel to the secondary slow port in the carb base. When the throttle linkage is opening the secondary butterfly, the lever also opens the valve, so fuel can flow out the secondary slow cut when the second barrel is opening.

Dangit, Beaufort, you type faster than me.

 

[HeadacheManNYC]

Though Grant has not noticed or doesen't care, it does make a noticeable difference. W/ the secondary slow circuit totally closed off, there is a stumble as the secondary opens, since there is no fuel flow initially.

A better application of Grant's technique is to break the arm off the valve and extract the plunger guts. Then thread a small stubby bolt into the plunger hole. Now the valve is always open inside, but cannot leak outside. IOW, the carb now works like any other non-smog unit.

That's another freebie, y'all can keep that.

Jim - is there a trick to getting the plunger bits out?