1982 F250 4x4 351W auto

[nic55kel]

It's an open center spacer.But the problem got worse: I have taken the intake manifold away and I discovered this:

Two pushrods were bent. So more work to do, but very little time at the moment

My experience with bent pushrods is sticky valves. If the valve guides are all gummed up it over stresses the pushrod.I would check for the valves moving freely. Remove the rocker arms and smack the valve with a dead blow hammer.It will be very obvious if the valves are sticky.I am having a similar problem with a 300 six that I ran on bad/old contaminated fuel.Good luck.

[Wagoneermaster]

My experience with bent pushrods is sticky valves. If the valve guides are all gummed up it over stresses the pushrod.

I would check for the valves moving freely. Remove the rocker arms and smack the valve with a dead blow hammer.

It will be very obvious if the valves are sticky.

I am having a similar problem with a 300 six that I ran on bad/old contaminated fuel.

Good luck.

I have already taken the head off. I have also checked the first valve of which the pushrod was bent. Sticky as superglue. I had to use a punch to gently tap the valve out of the guidance. The guidance is so gummed up, that I am not able to push the valve in, after genlty using scotch-brite on the head of the stem. I also do need to look at the lifter, but it seems that the pushrod caught the retaining ring from the lifter, at the moment the pushrod was snapping out of it.

Since some amount of the gasket between the carb base and the carb spacer, came loose and dissapeared, I figured the valve guides are gummed up by gasket partikels. Maybe a bit dissolved in fuel and than stuck to the guide walls? I don't know. But maybe very old fuel. Before connecting the fuel tank to the fuel pump, I have flushed the fuel tank and fuel lines with new fuel. I also place 2 fuel filters in the fuel lines. One between the tank and the pump and one between the pum and the carb. But I have no clue about the history of the truck.

Anyway, I need to make it work again. Does anyone have tips for me on how to un-gumm the valve guides? I was thinking of spraying a dissolvent in the valve guides and use a nylon or brass circular brush (gun barrel cleaning brush kind of thing) to get the stuff out.

To be continued.....

[Gary Lewis]

I have already taken the head off. I have also checked the first valve of which the pushrod was bent. Sticky as superglue. I had to use a punch to gently tap the valve out of the guidance. The guidance is so gummed up, that I am not able to push the valve in, after genlty using scotch-brite on the head of the stem. I also do need to look at the lifter, but it seems that the pushrod caught the retaining ring from the lifter, at the moment the pushrod was snapping out of it.

Since some amount of the gasket between the carb base and the carb spacer, came loose and dissapeared, I figured the valve guides are gummed up by gasket partikels. Maybe a bit dissolved in fuel and than stuck to the guide walls? I don't know. But maybe very old fuel. Before connecting the fuel tank to the fuel pump, I have flushed the fuel tank and fuel lines with new fuel. I also place 2 fuel filters in the fuel lines. One between the tank and the pump and one between the pum and the carb. But I have no clue about the history of the truck.

Anyway, I need to make it work again. Does anyone have tips for me on how to un-gumm the valve guides? I was thinking of spraying a dissolvent in the valve guides and use a nylon or brass circular brush (gun barrel cleaning brush kind of thing) to get the stuff out.

To be continued.....

I use O'Reilly's store-brand brake cleaner for lots of things, and that would be my go-to for that task as well. But I think I'd start with a Nylon brush as a brass brush might score the guides.

[nic55kel]

I have already taken the head off. I have also checked the first valve of which the pushrod was bent. Sticky as superglue. I had to use a punch to gently tap the valve out of the guidance. The guidance is so gummed up, that I am not able to push the valve in, after genlty using scotch-brite on the head of the stem. I also do need to look at the lifter, but it seems that the pushrod caught the retaining ring from the lifter, at the moment the pushrod was snapping out of it.

Since some amount of the gasket between the carb base and the carb spacer, came loose and dissapeared, I figured the valve guides are gummed up by gasket partikels. Maybe a bit dissolved in fuel and than stuck to the guide walls? I don't know. But maybe very old fuel. Before connecting the fuel tank to the fuel pump, I have flushed the fuel tank and fuel lines with new fuel. I also place 2 fuel filters in the fuel lines. One between the tank and the pump and one between the pum and the carb. But I have no clue about the history of the truck.

Anyway, I need to make it work again. Does anyone have tips for me on how to un-gumm the valve guides? I was thinking of spraying a dissolvent in the valve guides and use a nylon or brass circular brush (gun barrel cleaning brush kind of thing) to get the stuff out.

To be continued.....

I would bet that the problem was fuel contamination. Fuel that sits in the tank for years slowly oxidizes and turns into

something resembling varnish. When one decides to resurrect the truck the varnish gets carried into the intake and

deposits there and on the valves. It works okay when the engine is hot but when it cools it sets up like tar.

I had flushed the tank on my truck and that obviously was insufficient.

Gary had suggested lacquer thinner to me and I have had some success with that.

I feel your pain as I am still in the process of cleaning my cylinder head and valves.

I too am hoping that the camshaft and lifters have not been damaged.

[Wagoneermaster]

I would bet that the problem was fuel contamination. Fuel that sits in the tank for years slowly oxidizes and turns into

something resembling varnish. When one decides to resurrect the truck the varnish gets carried into the intake and

deposits there and on the valves. It works okay when the engine is hot but when it cools it sets up like tar.

I had flushed the tank on my truck and that obviously was insufficient.

Gary had suggested lacquer thinner to me and I have had some success with that.

I feel your pain as I am still in the process of cleaning my cylinder head and valves.

I too am hoping that the camshaft and lifters have not been damaged.

Due to having not too much spare time, it took a while, but I finally assembled the engine again. At least, most of it. It appeared that in total, 4 push rods were bent. All intake valves and all of those valves were sticky

Hopefully this weekend I will finish the engine again. But I had taken all valves out and cleaned the head, valve seats and valves inside & out.

But now I am a bit afraid the start the engine again. I am not 100% sure about the cause. Was it partial gasket material or just a tiny bit of old fuel inside the tank. I thought the tank was empty in the first pace. I have poured in about 30 litres of fuel. The first couple of litres were only used to flush the fuel lines and the fuel pump. I have discarded that amount of fuel. But what to do next??? I have ordered a bottle of Ethomix. This additive should also clean up gumming issues. Does anyone has experience with this stuff? Any tips or tricks to prevent a second overhaul ?

Help is very much appreciated.

[Gary Lewis]

Due to having not too much spare time, it took a while, but I finally assembled the engine again. At least, most of it. It appeared that in total, 4 push rods were bent. All intake valves and all of those valves were sticky

Hopefully this weekend I will finish the engine again. But I had taken all valves out and cleaned the head, valve seats and valves inside & out.

But now I am a bit afraid the start the engine again. I am not 100% sure about the cause. Was it partial gasket material or just a tiny bit of old fuel inside the tank. I thought the tank was empty in the first pace. I have poured in about 30 litres of fuel. The first couple of litres were only used to flush the fuel lines and the fuel pump. I have discarded that amount of fuel. But what to do next??? I have ordered a bottle of Ethomix. This additive should also clean up gumming issues. Does anyone has experience with this stuff? Any tips or tricks to prevent a second overhaul ?

Help is very much appreciated.

If you've gone to those lengths to clean the fuel system it is probably good. But, a new fuel tank isn't all that expensive, so if you are still concerned that would be my suggestion.

It is possible that there's enough old fuel that's turned into varnish in the bottom of the tank to cause problems as it softens and comes up and out later. And while I don't have any experience with Ethomix, I can't imagine that a small bottle of anything would clean out the system w/o causing other problems.

And I doubt that a fuel filter is going to catch varnish. A filter would catch big chunks of it, but wouldn't the real issue be that there's so much sticky stuff in solution to gum up things? Not big chunks?

Don't get me wrong, I think two filters is a good idea, but if the issue is gummy fuel then that probably isn't going to fix it.

[Wagoneermaster]

If you've gone to those lengths to clean the fuel system it is probably good. But, a new fuel tank isn't all that expensive, so if you are still concerned that would be my suggestion.

It is possible that there's enough old fuel that's turned into varnish in the bottom of the tank to cause problems as it softens and comes up and out later. And while I don't have any experience with Ethomix, I can't imagine that a small bottle of anything would clean out the system w/o causing other problems.

And I doubt that a fuel filter is going to catch varnish. A filter would catch big chunks of it, but wouldn't the real issue be that there's so much sticky stuff in solution to gum up things? Not big chunks?

Don't get me wrong, I think two filters is a good idea, but if the issue is gummy fuel then that probably isn't going to fix it.

Hi Gary,

Thanks for the reply. I have been looking for fuel tanks here in the Netherlands, but that is not so easy. Shipping from the US can be done, but the cheapest tank would set me back about $350 (that includes shipping, taxes and import duties)

Perhaps I can get an aft tank from a later year a bit easier. Do tanks from 1996 also fit the 1982 truck?

In the meanwhile I will also keep on looking for a way to clean the tanks.

[Gary Lewis]

Hi Gary,

Thanks for the reply. I have been looking for fuel tanks here in the Netherlands, but that is not so easy. Shipping from the US can be done, but the cheapest tank would set me back about $350 (that includes shipping, taxes and import duties)

Perhaps I can get an aft tank from a later year a bit easier. Do tanks from 1996 also fit the 1982 truck?

In the meanwhile I will also keep on looking for a way to clean the tanks.

I forgot where you are!

Yes, the later tanks fit, sorta. I'm running a '96 tank in Big Blue and it fit perfectly. BUT, you need to run the '96 fuel delivery module as the slots in the tank don't match the Bullnose senders. And the later FDM's have a pump, switching valve, and sender in them.

You could notch the new tank's opening to take the Bullnose sender, but you'd need to paint the notches to ensure they don't rust as you'd be taking the galvanizing off.

Or, you could do as I did and use the later FDM, but that creates several problems. First, the switching valve needs power to it and you don't have power to your tank so you'd have to run a wire for that. Second, you don't want the pump to run, and I think you could cut the wire to the pump to prevent that. Last, the sending units have a very different resistance range and your gauge would read backwards and wrong. That can be fixed with a MeterMatch, but that's more money.

So it is probably best to try to use your tank.

[Wagoneermaster]

I forgot where you are!

Yes, the later tanks fit, sorta. I'm running a '96 tank in Big Blue and it fit perfectly. BUT, you need to run the '96 fuel delivery module as the slots in the tank don't match the Bullnose senders. And the later FDM's have a pump, switching valve, and sender in them.

You could notch the new tank's opening to take the Bullnose sender, but you'd need to paint the notches to ensure they don't rust as you'd be taking the galvanizing off.

Or, you could do as I did and use the later FDM, but that creates several problems. First, the switching valve needs power to it and you don't have power to your tank so you'd have to run a wire for that. Second, you don't want the pump to run, and I think you could cut the wire to the pump to prevent that. Last, the sending units have a very different resistance range and your gauge would read backwards and wrong. That can be fixed with a MeterMatch, but that's more money.

So it is probably best to try to use your tank.

Slowly, but steady, I am making some progress. The engine is kinda back to where it was.

Now I am focussing on the fuel tanks. Before, I used the midship tank. Again drained it and look at the difference between gas that I have put in the tank about 2 months ago and fresh gas:

Guess what is what...

I have also put some gas, about 20 liters, in the aft tank. I also put about 50cc of cleaning stuff in. After some flushing, it looked pretty similar to the fresh gas. I let it rest for a couple of day, but if it remains like this, I plan to fire the engine up again this weekend...

Fingers cossed

[Gary Lewis]

Slowly, but steady, I am making some progress. The engine is kinda back to where it was.

Now I am focussing on the fuel tanks. Before, I used the midship tank. Again drained it and look at the difference between gas that I have put in the tank about 2 months ago and fresh gas:

Guess what is what...

I have also put some gas, about 20 liters, in the aft tank. I also put about 50cc of cleaning stuff in. After some flushing, it looked pretty similar to the fresh gas. I let it rest for a couple of day, but if it remains like this, I plan to fire the engine up again this weekend...

Fingers cossed

Looking good! But that old gas looks baaaaad. Glad you replaced it.

Here's hoping your startup going wonderfully.