New guy. 1984 720

[2 timer]

I got my weber carburetor all hooked up and now the only problem is that it still over heats I even took the thermostat out to let anti freeze run freely but it still just get really hot. What the hell am I doing wrong?

[2 timer]

Sorry for the language.

[2 timer]

Really, really could use some help on this little predicament.

[synack7350]

with the thermostat out take your hand and pinch off the top radiator hose. then let go. do you feel a surge? if not your pump could be shot. Otherwise running your carb too lean will cause it to over heat. if you are missing your fan shroud even with full flow at a stand still eventually you are going to over heat. with the mech fan, and shroud in place and you're not moving will cause it to get hot. I haven't let mine sit long enough idling to see if it will over heat.

this isn't an exhaustive list of what can cause overheating but it give you a good starting point. If it were mine I'd ensure the pump was working. My carb mix wasn't too lean. then flush the rad, and replace with just water (no coolant) see if it still overheats. If not then add 50% glycol to the mix and see how it does. Glycol isn't as thermally conductive as straight water is. If your glycol mix is too rich besides eating up everything its not going to cool as efficiently.

[woodbutcher5691]

I can think of two things here. 1st would be that the water pump impeller has eroded away so much that it can't push coolant through fast enough or 2nd, the radiator is all cruddy and needs to be rodded out or replaced. If that's the case,the head may be stopped up as well.

[woodbutcher5691]

if you are missing your fan shroud even with full flow at a stand still eventually you are going to over heat. with the mech fan, and shroud in place and you're not moving will cause it to get hot.

I've ran mine for many years without a shroud and never had a problem with overheating. Juss sayin'

[synack7350]

at idle without a fan shroud? the fan barely turns with the motor at 650 rpm. You are hardly pulling any air across a corroded rad. Without a shroud path of least resistance being engine heat inside the bay. You're actually heating up the rad.

[woodbutcher5691]

at idle without a fan shroud? the fan barely turns with the motor at 650 rpm. You are hardly pulling any air across a corroded rad. Without a shroud path of least resistance being engine heat inside the bay. You're actually heating up the rad.

Yes. Come to think of it, I don't remember it having one when I got it.

[fastboatman29212]

My vote is to pull the radiator and have it rodded if it can be salvaged. Better than that is a new Autozone radiator for $150 or RockAuto for $92 plus shipping. Salvage yard stuff is probably a waste of time unless you find one that was recently replaced. I bet they'd charge you $50 or more to have yours rodded.

[2 timer]

Ok well the thing is not even two weeks ago the truck didnt over heat and then I replaced the intake manifold and at the time I did that I replaced the thermostat with a brand new one and replaced all the thermostat wires and thats when it started getting hot. I then replaced another intake manifold and when I toke the hoses off the bottom portion on the manifold where it has an inlet and outlet water connection there was water moving through that so that would indicate that everything up to that point is working right, Right?

[2 timer]

And when I take the radiator cap off I see that the water pump works because the coolant flows while im lookin in the radiator? If that helps someone with helping me.
When im lookin at the flow through the top of the cap sometimes it spirts up coolant when its flowing!

[fastboatman29212]

If the radiator is clogged with rust and corrosion, then it will not cool the fluid well, even though it is moving through the radiator. Basically it would only allow it to partially cool the fluid.

Here's what I'd do cause I hate tearing stuff apart and later find out that it wasn't the problem.

First, I'd pop off the radiator cap and start the motor cold. If the water pump is working well (I assume the thermostat is still out) then you should have a steady and strong flow of fluid coming across the top of the radiator and you can see it with the cap off. That should pretty much confirm that your water pump is working well.

Next, before pulling everything apart, run the motor until it gets overheated and then use a thermometer or some other gauge to get a "true" temperature of the radiator fluid. Maybe the dash light is not right and it's not really too hot. I don't know exactly what you did with the "replaced thermostat wires" but it's good to look at this systematically. You could choose from a number of tools to measure the actual temp of the radiator fluid, there are even super easy to use infrared temp measuring tools that you could borrow from a shop or friend.

http://shop.advanceautoparts.com/webapp ... _T|GRP2001_____

Then, if it really is too hot, to me, it has to be the something wrong with the only thing that cools the fluid - the radiator!

[2 timer]

It gets hot for sure the gauge aint lyin because the coolant burst coolant burst out when I take the cap off. And like I said the inlet and outlet "Y" shaped valve on the bottom of the intake manifold has water in it when I pull the hoses on the, there are no leaks at all so that wouldnt be why its over heating...

[woodbutcher5691]

Ok well the thing is not even two weeks ago the truck didnt over heat and then I replaced the intake manifold and at the time I did that I replaced the thermostat with a brand new one and replaced all the thermostat wires and thats when it started getting hot. I then replaced another intake manifold and when I toke the hoses off the bottom portion on the manifold where it has an inlet and outlet water connection there was water moving through that so that would indicate that everything up to that point is working right, Right?

Sounds like you got an incorrect mani gasket. It should have all the holes in the gasket that are in the head. You have serious blockage somewhere
How old is the water pump BTW?

[woodbutcher5691]

I missed your last post. As bad as I hate to say it, I think your looking at replacing the head gasket

[woodbutcher5691]

It gets hot for sure the gauge aint lyin because the coolant burst coolant burst out when I take the cap off.

Ain't good

[2 timer]

Ok so I drained all the water out of the radiator at the bottom of it and I reattached the hose at the bottom of the radiator and before that I blew through the top just to see if air was getting through and I could see water come out from the bottom everytime. So after putting the hose back on I went and bought some radiator coolant and also a filter and regulator for my carb (Mr.Gasket regulator) and I placed every thing on and put the fluid in and started the truck ran around town for 15 minutes and it did not over heat or get hot so I guess I fixed it!
But I need to figure out which wires from the truck hook to the choke switch on the carb, on my truck it has two wires for the anti diesel switch and one is blue and the other is blue and white it keep dieseling out fuel any tutorial on how to hook the wires up. I have the weber carb if that helps!

[2 timer]

Any body at all know what I hook the wire from the carb to? Anybody?

[fastboatman29212]

If you need to hook wires from the Weber to the truck, I'm not gonna be able to help. Sure wish I could. The guys with the Weber carbs would probably like to see a picture to get an idea of what exactly you are referring to.

[2 timer]

Its so it doesnt diesel out all the fuel when I cut the truck off. Im am just not a electrical guy

[2 timer]

Someone has to know where this wire connects to, cause I look like an idiot everytime I shut my truck off and it diesels out the rest of the fuel!

[2 timer]

Or maybe just point me in the right direction!

Thanks

[synack7350]

weber doesn't have an anti diesel solenoid. The only electrical connection is one wire for the electric choke. As far as dieseling goes. I don't have a problem with it with my weber.

[2 timer]

I have a brand new 32/36 weber carb and everytime I run it for more than 5 minutes and then shut it off it diesels the rest of the fuel out. There has to be something I can do to prevent this?

[synack7350]

can you take some pictures of it? It shouldn't be dieseling like that. this is with the choke plates wide open? hell it shouldn't even be that hot after five minutes. How does it idle?

[2 timer]

It idles fine. runs great also.

[synack7350]

are your choke plates wide open when it diesels ?

[2 timer]

I have no idea. I will connect the wire from the weber carb to the blue wire tomorrow and let you know!

[synack7350]

right on. that might take care of it. um you didn't tune the carb with the choke closed did you?

[2 timer]

Thanks for the help so far though man really preciate it! I didnt tune anything, I just threw the weber carb on there when I got it