LUVTruck.com

Greetings All,

I have a major problem and I need help so I can get to work in the morning!!!

1979 Chevrolet LUV 4X4 bought 3 months ago.
(only problems so far have been loose alternator and minor oil leak)

On the way home last night I noticed that I was going too fast.
I let my foot off the gas and slowed a little.
I popped it out of gear and the engine took off.

When I got home I looked for damaged vacuum hoses and found nothing.

General inspection reveals nothing major.

There is an oil leak that has been putting some oil in engine compartment.
(I have replaced the valve cover gasket but that was 4 months ago)
(the leak appears to be coming from the timing cover)

The distributor is not loose.

On my way out now to check the throttle plate for slop and snap a couple pics.
(Pics to follow in a few minutes)



What happened? Where do I go from here? What carb is this?

Thank you in advance for your time.

Clint

the date is off on my camera... I just took those pictures. Didn't find any sloppiness in anything on the carb.
Was operating perfectly on the way to work, is there some electrical control device?

well, start with the obvious stuff first. make sure the accel cable is not kinked or damaged. then check to make sure the butterfly plate is not stuck open. I would consider a rebuild as a later resort, but make sure everything is free and clear.

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To the Oquirr hills for awesome thrills! Go-go 4wd, Activate!

well one thing is what about the t coming out of the valve cover and then hit it with wd-40 all over see if that changes anything if there is a leak the wd-40 will temporary make it stop then you can look in that spot just an idea

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http://www.facebook.com/ez.cracker
dangerous-toys4life
73 3-door avalanche bdydropped on 18s
86 1-ton 4x crewcab short bd 15"lift
75 k-5 2x
94 king cab

Butterfly not stuck, cable is free and in excellent shape.

Not leaking anywhere I can find.

Its rapping out hard, it will hold 55 in 4th with no accelerator...

i have been having a charging issue, thought it was the battery...

Thanks to both of you for the fast reply!

Please keep it coming everybody!

That's the stock hitachi carburetor.

If it's revving high, but running smooth, the problem can only be a throttle plate open too much. Any leaks, like vacuum leaks, would make it run rough.

When it's at idle, the secondary throttle plate should be fully closed. If it's open at all, then something's wrong with it, or with the mechanism that opens it.

At idle, the primary throttle plate should be almost closed.

I notice from your picture the choke is almost closed. I assume it's because the truck is cold. However, when the choke is closed, it bumps the idle up. If the choke isn't fully opening, the truck will idle too fast.

Look carefully at the throttle mechanism on the carburetor. I suspect something's keeping it open too much. Things I've seen that could cause this:
- a weak return spring not pull the throttle all the way back
- the choke mechanism not allowing the throttle to fully close
- the throttle cable catching on the carburetor and not allowing the throttle to fully close.

Hope this helps.

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You went there in that?!?!

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To the Oquirr hills for awesome thrills! Go-go 4wd, Activate!

Make sure your choke is working correctly as i bet if it is on fast idle that you could drive it at that speed as most are set to fast for my liking.

Leave the air cleaner off check that the wires to the carb are connected then stat the truck and watch the choke as it should take only a couple of minutes for it to start to open then make sure it opens all the way.

My choke pull off used to pull the choke off when the motor was warmed up but the pulloff is getting bad.

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1978 pro street step/side 455Buick, 4sp,4.11s, 31/18.5s

And check the fast idle solenoid...

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If you think no one cares, try missing a couple of payments...



FIAA!

SFPP!

I suspect maybe the wire fell off the electric choke or it lost its 12V power and the choke went to fast idle when it cooled off while driving. The choke internal heater could also fail.

Thank you all for these suggestions.

egg> the wire is attached. I will test the voltage

mytmouz> the wire is attached, how can i test it?

tjwhite> the engine is revving out hard, i can't stand to let it run like that, just sitting there. In desperation, I drove it to work today and will have to again tomorrow. The choke is free and no difference is noted when holding the choke open.

1okey2go> thank you for id on the carb. it seems to fully operational as far as linkages and closing of plate etc.
I have operated the throttle manually with the engine running it is coming all the way back.

Thanks again all, but this persists, anybody know which parts store carries the idle parts? Autozone does not.

its not like high idle, its like i am holding my foot on the gas pedal. but with the cable unhooked its still revving.
i was driving down the road like any other day, nothing special had happened or been done. Just started taking off.
Very hard to navigate town... destroying the clutch... no money for a "professional" (grew up on a junkyard fixing chevy trucks all the time... but this is not a chevy except in name. now don't get me wrong, i love my LUV. wanted one for years. plan to have this one around a long time. once i figure this out, i think a newer style distributor and...

but I have to drive it now. and this has me stumped. never was any good with the import motorcycle engines/carb issues not gonna cram a small block in it. thats not what i want from my LUV. i want it for what it is, an economy Light Utility Vehicle.

more as it develops...

Check your vacuum secondaries. Sounds like it's sticking. Spray a little carb cleaner on it to free it up. Check to make sure nothing is binding it or if it's loose. Stick a pencil in it and open it and the motor should accelarate and see if it returns to it's reg position when you let go.

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Ok, got some extra time before work this A.M. Took the carb off and turned it over.

The secondary plate was indeed held open.

by this:


It was lying on the top side of the secondary, sticking out just a little and holding it open.
It was held there by just a bit of oil creating suction kinda.

Where did this piece come from? It is made of steel. What is it?

I looked through a rebuild kit a my friends shop, didn't see it.
He happened to be rebuilding the SAME carb but off a 1970 Datsun... imagine the odds.
He told me he didn't recognize the piece from anywhere.

Thanks again all for your input.
I know this is the wrong part of the forum to ask but anybody got spare rebuild kit parts of any kind they want to off load?
Also in the market for alternator, starter, exhaust pipe, muffler, stock fog lights?, gasket set, newer style distributor?

About the new style distributor, what is involved with swapping that? is it a good idea?

Thanks again for the info and trying to help me with this issue, who could have guessed. but you guys were right, it was stuck, just not on the outside. Thank God that this piece didn't make in inside the engine! Ouch!

One more thing--disconnect the coasting richer solenoid wire and see if that helps. Its the round cylinder thing sticking out towards the valve cover, maybe try rapping on it in case it is stuck.

Carb cleaner and work the vac.secondary you can also take a good flashlight and look at the secondary throttle blade and see if it is open any.Also grab the top of the carb and twist to see if it moves, if it dose move any then the screws are loose that bolt the base to the body.

Better yet pull the carb off then look at the throttle blades i bet the secondary is stuck part open then tighten all screws.

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1978 pro street step/side 455Buick, 4sp,4.11s, 31/18.5s

There is a bi-metal operated thermo vacuum valve inside the stock air cleaner that operates the warm air door in the air cleaner snout. Could it be part of that? It is about the right size.

Except for it being metal it looks like the lid to a hitter box. I say you got lucky it got stuck where it did.

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1980 4x4

AMEN!

2X

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1978 pro street step/side 455Buick, 4sp,4.11s, 31/18.5s