LUVTruck.com

Yes the throttle closes on its own. The choke thermostat and vacuum actuator are missing along with whatever else attaches to that assembly. (I have pictures attached to one of my previous posts, a few posts up, showing what is missing) When I close the choke flap it bogs down and nearly dies then idles and blows black smoke (over fueling) and when I have the choke flap wide open it revs really high regardless of throttle position. No matter what though it seems to be over fueling, I think the carb jets or needle are excessively worn.

EDIT: And when I go to shut the key off it stays running and I disconnect the fuel pump wire and it still runs until the carb runs dry, is this another common issue?

I've been messing with it for two days now and I think need to either find a better carb or the missing parts for the current carb to fix this issue methinks.

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned

Well it should definitely shut off with the key. That it likely a wiring issue. Either someone wired the coil to be hot all the time, or there is a short in the harness powering it somehow. I'd look over any non-stock wiring around the coil and fuel pump relays. Sounds like someone has gotten creative to me. I did have a short in my 79 that did this though. The main alternator wire had melted in the harness and melted a couple other wires. It had shorted battery power to the wire for the reverse lights, which back fed through the rest of the switched ignition powered part of the harness to power the coil even with the key off.

The carb sounds likely that it has already been tweaked and messed with. The idle mixture screw might be WAY out and causing it to run rich. Sounds like it won't do any more harm to mess with it than has already been done. The idle mixture screw is in a recessed hole in the cast iron base of the carb facing the passenger side fender. Tighten that screw until it bottoms out (gently, its a needle valve threading into a seat. AND Count the number of turns until it bottoms You need to know where its at to begin with before you do any adjusting and to try to troubleshoot what it is doing.

If I recall correctly you start it at about 1 1/2 turns out and adjust from there. If it is adjusted way farther out than that then it could be the source of the high idle. I remember some write-ups here in the past, probably search for "mixture screw" will find some good info.

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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good

Well once the key is off it starts to run really bad like it's trying to shut off but doesn't stop completely until the carb runs dry. I'll have to look into it.



It was supposedly rebuilt from what the previous owner tells me. I've messed with the AFM adjustment screw, but no significant change. That is the screw you're talking about correct? The screw on the outside of the carb at the bottom with the spring on it?

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned

This one would work, right?

http://www.ebay.com/itm/Hitachi-DCH340- ... 65&vxp=mtr

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned

Doesn't look correct for a LUV throttle cable, lets see what 800 says since he knows a ton more on the stock stuff then I

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Certified pilots, looking down on people since 1903.

Well I tried tinkering with the carb some, definitely over fueling, it's burned up the 2 gallons I put in the tank and is now out of gas, have to wait for payday to get more gas.

But I noticed both the idle screw (The next to the throttle mechanism with the spring around it?) and the AFM screw (the one at the base of the carb with a spring around it?) were both adjusted ALL the way out. Turned them both all the way down and tried to start it to adjust from there, but no gas. (Pulled fuel line off and turned on fuel pump and could hear the fuel line bubbling from no gas in the tank.)

Looks like its time to play the waiting game lol

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned

That is likely the problem to begin with. I don't know what it is about these carbs that is so touchy, but rebuilding them is like some sort of voodoo art form.

That ebay link I don't know about. It looks similar to a LUV carb but I see a few different parts.

The running after the key is shut off could also be the anti-dieseling solenoid on the carb. It should have one wire coming out and I think its on the engine side of the carb. The choke should have also had a wire going to it too, so you might have some missing wiring there or something just not plugged in.

You might check the pressure your fuel pump is putting out. If it is too high it could be blowing past the needle valve into the carb. You could also have a sinking float. The fuel level should sit right about in the middle of the view port in the front of the carb.

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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good

I will check that. The pump is a 5-9 psi universal pump from RockAuto.

But even if I leave the fuel pump disconnected and hook up a hose with a funnel on it (and slowly pouring fuel) to the fuel port on the carb, it still idles high.

EDIT: Also noticed that the portion of the fuel line from the tank to the fuel pump had split (old hose). Fixed it up and fuel is back! lol

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned

So I'll post it here instead of my carb rebuild thread since this relates to more possible missing parts?

I noticed the secondary was staying wide open, which is causing my high idle issue (I think?).

I noticed that the metal arm on the throttle linkage was dangling below the secondary linkage. It's supposed to sit on top correct? When moving the throttle only the primary valve opens, while the secondary stays open.

I took the throttle linkage apart and re-aligned the metal arm, shown in the attachments. (Circled in red in one of the two photos.) Now when moving the throttle both secondary and primary valves open, but the secondary won't close all the way and if I use my finger to push it closed all the way, the throttle won't open at all...

When on the motor the throttle seems to get stuck, if I mess with the secondary to free it up (opening it slightly) the truck lets off a loud BAAAA then dies. BUT it does idle more normally now... My problem now is the sticky throttle...

Note: when doing this I had the carb upside down on the table so that the throttle valves would not get bent up or snagged on the table.

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned

Here are some pics of the throttle valves "closed" and "open".

You can see in the closed pic how the secondary stays slightly open. If I push it closed it locks up the throttle and is hard to get the throttle open.

I've also notice how the primary won't open completely when I hold the throttle open. Whoever rebuilt this carb must've got some pieces backwards?

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1980 Chevy Luv (1.8L I4, 4-speed) - Should never have bought this pile of crap
1987 Nissan 300ZX (3.0L V6, 5-speed) - Best car I've ever owned