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i've replaced the head gasket to take care of the engine problems the engine had. its an 80 4x4 stock except for a header, but it idles smooth picks up rpm good , then starts cutting out about half throttle it then misses till wide open.it doesn;t get better. it doesn not pop back through the card. could it be in the distributer. the timing is ok what do yall think? yall helped out alot on other problems..

thanks alot...... 804x4

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A 1980 luv that chevy 4x4

Cap off all the little vacuum ports, except spark advance, on the carb and intake manifold and see if it settles down. If so, start putting hoses back on until you find the culprit. The EGR valve was flaky on mine.

Checking for vac leaks is the best place to start. If its not vaccum it is probably points. My 76 used to eat points every 8-12 thousand miles and behave just about like that. Look the points over carefully and see if one or the other side is pitted. In my experience they pit on one side and build up on the other. Eventually the gap gets so far off it won't run right anymore. Watch taking them out and trying to reuse them if they are like this, gapping with a feeler guage doesn't work so well when they are screwed up. I took out a muffler that way once.

You might also check the seating on your intake manifold. You could have a vac leak coming from there. An easy way to check is to let it idle and squirt a little carb cleaner or something around each port. If it leaks, you'll hear a change in RPMs when you spray over the leak.

Failing everything else, it could be lack of fuel. Change the filter back by the tank and clean the screen on the top of the carb. (You take off the hose fitting to get to it) Wouldn't hurt to check the flow from the pump as well. The motor will idle a while with the hose off and stuck in a jug or measuring cup. Take the hose off, then start it and measure for 20 or 30 seconds. I forget how much you should get, but if it just trickles you can figure the pump is pretty sad. This test is best done with a buddy, as spraying gas all over the engine could make for a bad day.

vacuum leaks thats why mine's not on the road anymores
i could never get them right

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1980 luv sport 4x4 Just a memory now
Frame rusted from the inside. Truck stripped and now looking for a new donor in southern ohio

My toyota does the same thing when i hit the throttle to take off. i just dont worry about. what you could try is putting some fuel cleaner in the tank. just make sure that you have a full tank.

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Currently no more luv's... But in search of one!

thanks alot, i replaced the points, plugs, condenser,rotor button, cap and wires when i got it plus 2 inline fuel filters before i got it to run.what if the vacume advance doesn't work? or tell me is there only 1 way the distributer goes in?thecap with #1 on it is up tword the front of the engine and the vac. advance points down toward the frame. the engine has no emission stuff on it as i can tell. it has a header on it and i don't have an exhaust on it right now. what do you think???


sorry for the length
thanks alot 804x4

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A 1980 luv that chevy 4x4

The distributor can go in two ways and only one is right. The other is 180 degrees out. With the distributor in, the turn the engine over until the pointer on the front of the engine points to the TDC timing mark on the crank pulley. The rotor should point to the contact in the cap that # 1 spark plug wire connects to on the compression stroke.

Pull the spark advance vacuum line off the carb or intake manifold. Suck on the vacuum line. If you can draw air, the diaphram in the spark advance is leaking.

i'll try that tomorrow.. its dark here in ala. tell me.. the engine shouldn't run if it is 180 off -- right??? when I changed head gaskets last weekend, before I took the head off I made sure the timing marks were lined up and that the rotor button was under the number one connection on the distributor cap. I have not had the distributor completely out since I've had the truck. Somebody else may have. Tell me this, with the distributor in the truck the number one on the cap is pointing towards the radiator. The vacuum advance is pointing down toward the frame. Should it be the other way around. I've got the book the Haynes repair book, and it's kind of vague on that. Any help would be appreciated. Again, this is kind of a father and son project (mostly me) if you know what I mean. But I'll check the vacuum advance tomorrow. Thanks again.


804/4

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A 1980 luv that chevy 4x4

While you can put the distributor body 180 out, you'd have the hose for the vac advance pointing towards the radiator. The shaft can only go in one way. The end looks like a flathead screwdriver tip, but the tip is off center. It won't go in wrong. The only way to get it 180 degrees off is to twist the body of the dist around. On mine, the port on the vac advance points about straight back I think, but I'll have to to go take a look.

The engine will run even with the timing quite a ways off, but I'm not sure if it will run 180 out without swapping some plug wires around. From the sound of where your distributor is pointing with the timing correct, you might have the timing chain a tooth or two off. That would explain the poor performance, and given the fact the head was recently off there is a possibility. It could have been wrong even before you got it. That is a lot to tear into just to check, but it does seem to fit the symptoms.

If you can get your hands on one, hook a vac gauge up to it and see how that looks. It is easy to do and would help to eliminate vaccum leaks from the list.

And if the vac advance isn't working it would not make a lot of difference other than leaking vaccum. Pull the hose to it and plug the hose with something (or cap the port on the carb it is hooked to) and see if it helps. No vaccum advance would basically just make it sluggish under a load like pulling a hill or accelerating.

What'd you do with the timing chain when you had the head off? Did you have the front chain cover behind the water pump off? If not and you didn't keep the chain pulled tight around the bottom, there's a good chance you're off a tooth or so down there even though the marks you put at the top line up.