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If you can take the air/fuel mixture screw all the way out and just plug the hole and it still runs, it means that you have a nasty little fuel leak in the carb, right? I'm not too terribly excited about this. I was just driving around and all of a sudden it started dying whenever I took my foot off the gas, and I'd have to feather it constantly to keep it running and even then it's runnin' like crap.

Does anyone know how hard it is to hold the clutch press the brake AND feather the gas in busy traffic?

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

Another thing is....check those wires that come off the carb an make sure theyre hooked up. On a luv i had awhile back those came undone on me after some off-roading and I was about to pull the carb and junk it and my son noticed my prob. plugged wires back in and it ran great

I'll check those first thing in the morning, cause I wasn't EXACTLY on a paved road when it went shitty. But I thought I did notice some gas leaking into the bore when I was trying to adjust the carb to keep it runnin'. I'll look at my book to try and tell ya exactly where it was leaking from.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

alrity then, yeah ya never know it may be somethin simple, maybe not....will help you trouble-shoot it the best i can

too bad it had to get dark, I'd be out there right now. Since I can't sleep with all the damned fire-works goin' off.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

my speed sensor has a intermittant short somewhere and i had to hot wire the idle stop solinoid to the ignition circut.

that sounds like the same symtoms my truck had too......if you look down into the carb and see large drops of fuel that's the ticket....the solenoid is the one behind the accel pump linkage. wire it to the input side of the balast resistor and see if that helps.

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If you can take the air/fuel mixture all the way out ...........?

Richard, what do you mean by the air/fuel mixture? The idle adjustment screw on the throttle body with the spring on it?

That is sorta what I was thinking. If you take it out, you should have one rich running truck, likely with fuel leaking out of the hole the adjustment screw was in. If you turn it all the way in then the truck should die unless there is fuel coming from somewhere else. I've never tried taking it all the way out before, but I would think it would need some sort of air leak somewhere to run that rich. Could be that even wide open on that adjustment isn't enough gas to starve it for air though.

As for running the brake, clutch, and feathering the gas all at the same time I usually run the gas and the brake with one foot when shifting. My other foot sits on the floor lazily as I shift 90% of the time without touching the clutch pedal.

I would guess vac leaks as the source of sudden running like crap. Most common source (other than cracked hoses) I've had was the air cleaner flapper deal. (Where it pulls hot air over the exhaust until the truck starts to warm up) I've had at least two of them develop serious leaks. Pull the air cleaner off and plug the line going to the T in the vac lines hanging from it.

sorry, meant to put air/fuel mixture "screw" in, but I guess I was thinking faster than I was typing.

I don't even have my "air cleaned flapper deal" hooked up so that's not it. I've got all the "non-essential" parts of the vacuum system plugged off. I'll go check all the lines one more time and try and give a better description of the symptoms.

But yeah, inside the bore I can see fuel dripping from under the blades that go across the bore.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

Well, I just checked over the entire vacuum system and nothing seems to be leaking. I know I've got a small air leak in the throttle shaft, something about bad bushings, but you can't get the butterfly's off without stripping the screws so I can't fix it.

I played with the a/f mixture SCREW, if I get the idle up enough to keep it from stalling I can turn the screw all the way in, and take it all the way out, (as long as I plug the hole with my finger after I take it out) and it still runs. And no, no fuel leaks out of the adjuster screw hole.

Also, All the wiring is hooked up right.

If you're not sure what I mean about my air flapper not being hooked up. Look at the pic of my engine in the gallery. You'll know what I mean.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

one of those selonoids on the carb is an anti-dieseling selonoid (aka idle selonoid) which makes sure your truck doesn't keep running after you turn the key off. so if that is not working properly your truck will run like crap while idleing. but if you idle it up, it will run fine.

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1980 chevy luv 4x4 1.8 liter
1979 luv long bed parts truck
1984 2wd isuzu pup parts truck

"A man who says it can't be done shouldn't interrupt a man doing it."

So is this a problem I'm gonna have to work around until I get a new carburator, or is there a way to fix this?

Is it the one that has a red wire in the end of a nut about three inches long? I might have one on my old carb if it is.

I'll swap that over tomorrow and see, if not any more ideas? Just asking so I don't have to wait for it to break down to know how to fix it, and for other people's references.

Thanks

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

Richard: Think about this. When you take out the idle adust screw and cover the outside hole with your finger, you've enlarged the diameter of the bore of the hole inside the throttle body. That needle end allows you to fine tune the mixture. Anyway, your allowing more fuel into the carb. That means the carb is getting more air somewhere to compensate for the extra gas. In other words, the carb's got a vacuum leak somewhere to allow it to suck extra air in. Get a can of WD-40 and spray around the places that bolt together where air could leak in. Base of the carb onto the intake manifold. Intake manifold to head. Etc. If the engine starts idling better while you're spraying any particular spot, then the spray is temporarily plugging a leak. Some guys like to use starter fluid for this. That could be dangerous.

On the other hand, a leaky needle valve seat would let fuel leak into the throat of the carb. How fast does it idle with the screw out. A real fast idle? Fast or smooth?

My carb just took a turn for the worst also. the secondary won't work at all, the vacum pump thingy that opperates the the secondary's butterfly doesn't seem to be working. it'll hold a vacum but when i get the thing started it doesn't work. I already tore the thing apart and put in a rebuild kit, and checked the wiring and the vacum lines but still nothing, so prett much i'm dead in the water with it. oh and by the way i know how hard it is to hold the clutch in and press on the brakes, AND feather the gas in heavy stop & go traffic, it sucks big time

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'80 Luv 4x4, 3" BL, 1.5" SL, 32/36, 2.25" exhaust...and fuzzy dice.
'95 Toyota 4Runner Limited 5-Speed.

What'll hold a vacuum? The carb? Vacuum is what opens the secondary. After the primary opens far enuf and unlocks the secondary linkage.

Robert: I'll try the WD-40 thing. I'm having trouble with the anti-dieseling solenoid because the one on the carb you gave me had the wire trimmed really, really short. But I honestly don't think that is it. I've got the carb tuned out and it runs a little better, it hasn't stalled on me today, but that may be because I set the idle kinda high. But when I have the screw out, it idles smoother than it ever has with any tuning I've done, kinda pissing me off.

Rezkid: Yuo really have to watch to even see the secondary open, you have to be looking right into the bore with the engine warmed up and romp on the gas. I've seen mine flap open for half a second, but was afraid my motor was gonna blow up so I left it be.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

do you have that idle selonoid hooked up? i'm not sure i read ur post right? you said the wire was real short so i don't know if you meant it was hooked up or not. if its not the truck will not idle. i've had mine run like crap and see it unplugged. you might also buy a vacuum gauge. they are fairly cheap. and will give some info oin a vacuum leak. plug up all the vacuum lines including the brake booster. it hooks up to the intake manifold. chances are the secondary barrels will never open up with you reving the engine up. only going down the road and you stomp on it and really load the engine down.

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1980 chevy luv 4x4 1.8 liter
1979 luv long bed parts truck
1984 2wd isuzu pup parts truck

"A man who says it can't be done shouldn't interrupt a man doing it."

do you have that idle selonoid hooked up? i'm not sure i read ur post right? you said the wire was real short so i don't know if you meant it was hooked up or not. if its not the truck will not idle. i've had mine run like crap and see it unplugged. you might also buy a vacuum gauge. they are fairly cheap. and will give some info oin a vacuum leak. plug up all the vacuum lines including the brake booster. it hooks up to the intake manifold. chances are the secondary barrels will never open up with you reving the engine up. only going down the road and you stomp on it and really load the engine down.

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1980 chevy luv 4x4 1.8 liter
1979 luv long bed parts truck
1984 2wd isuzu pup parts truck

"A man who says it can't be done shouldn't interrupt a man doing it."

I have the one on my truck hooked up, but the one on my spare carburator has the wire trimmed really short so I'm having trouble attaching another wire to it.

I've checked, double-checked, and re-checked all the wires and nothing is unplugged, I've double-checked my vacuum system, it there's a vacuum leak, it's in the carb.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

After 12 rebuilds, (yup, 12) I bought a weber 32/36 dgev. Why waste your time and give yourself headaches when you will have a much better carb with the weber.

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Hammer to fit, paint to match.
If it aint broke, don't fix it.
There's always room for duct tape and bailing wire.

WATCH YOUR PIEHOLE!!!!!!