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my latest luv , a 79 4x4 with a 86 isuzu moter , was cheper than a rebult and has more power. will lose power when the humidity is high, now tha the spring rains are here it makes it imposible to get to and from work on time. She just looses power slowley untill she will go no faster than 3 or 4 miles per hour,no sputtering just a slow los of power. let her sit for 5 minites and it is back to 70mph for about 20-25 miles then lossses popwer. i have peplaced the coil, destributercap ,sparkplug wires , sparkplugs, and carberator, and had the tank coated, and keep a suply of fuel filters on hand but have not been able to figure it out. i have also put silicone around the destributer cap to keep out any mosteure but no luck any help or ideas would be apreacated thanks

keep on luvin

ok here is my stupid suggestion. what about the air filter?

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I like my steak like I like my women, young, tender and bloody.

All I need is my weed, women, and wine. -Edge City Outlaws

Sounds possable that you might have a vacume leak. Also check to make sure your vacume advance is working.

This is the problem. Let me ask first, is the preheat pipe on the air filter housing, the one that goes from the exhaust manifold the the air filter housing. If not then what is happening is ice is forming in the venturi of the carb restricting air flow. When you stop the heat melts it and it runs fine, for awhile till it happens again. What causes this to happens in the venturi is due to the laws of heat flow and expanding gasses. as the air expands just past the the venturi it releases heat into the carb. If the air temp is close to freezing and the humidity is high, then ice forms in the carb. It is similar to the way airconditioning works by expanding the refrigerant and you get cold air. It is a simple fix to hook up the pipe and make sure the thermastatic valve works. If you look inside the filter housing you will see a devise that regulates vacuum to the air valve in the horn on the housing. If you have any questions just ask. I know this sounds rediculous, but believe me , it happens. Good Luck!

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1980 4X4 LUV

Mine used to do that with the fuel filter.... I'd let it sit for a while and it would run fine for a couple of minutes.

Something to think about.

the preheat pipe in missing , it does seem worse the colder it is. i will try to find a replacement, my spair luv did not have one, and see if that helps thanks.

Damm there it is --carb ice--. My Luv lives in Nevada the humidity run about 10 percent here but on rainey days (seldom) my Luv does just that.

I am a pilot and should have though of that but it seldom happended. Yes the carb heat tube is off and the primary venturi is very small it will hesitate and buck at low rpm but clear when the secondary cuts in.

Good thinking Rick Smith. Are you a pilot?

YW! No I am not a pilot, Even here in NC I have delt with the icing problem before. Most people never think of it, and spend unneccessarily to try and remedy the problem (electrical?). I own a c-store and have seen this happen to customers. Most of the time you can remove the hose that brings fresh air from the front of the vehicle to the carb. This usually gives the carb enough warm air to keep from freezing. And I am surprised you didn't think of carb icing! Being a pilot and all. He! He!
Just kidding! I really hope this was your problem.

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1980 4X4 LUV

Rick Smith has my vote. HE'S DA MAN. I am very impressed. I know I could have figured that out, but 20 years would probably been to long to wait for the answer.

This may sound off the wall, but when I swapped my stock carb for the weber 32/36, I didn't get the air/fuel mixture exactly right like weber wants. I was driving down the road, going about 40 mph and it was 75 degrees outside. Foggy. I noticed I had to keep giving it more gas to maintain 40 mph till it was floored. I pulled over and checked my carb. The entire base was iced over and the throttles wouldn't open smoothly. After about 3 minutes, it started right up and ran great. I re-set the mixtures as soon as I got home and have had no more problems with it. You may want to see if your mixtures are right, timing is right, and you have no vacuum leaks. Thats just my 2 coppers worth

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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!!!!!!

Whoever posted under "visitor". I know what you are going through on the aircraft thing. I work on planes for a living. Maybe a little prist is in order . Are you running 100LL in your luv? I put a little in my truck once. Ran pretty good but the engine isn't designed to run on 100 octane fuel with a lot of lead in it. It will fark it up eventually.

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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!!!!!!