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Hey guys

I just got my 56 3/4 ton 261(I think)running for the first time. It idled great and was running pretty well as I drove it around the neighborhood. The firs time I took it over 30ish all of a sudden it sputtered and died.

After a few minutes of sitting it started back up after lots of cranking, but it only ran for about 30 seconds before it died again. It did this about 4 more times running for a shorter amount of time each time and now it won't start at all.

It will try and start the first time i hit the starter but it just revs up a little and then dies and after that won't "hit at all"

It has a rochester 1 BBL.

This forum has been awesome! I've searched and found that maybe the carb is plugged from gunk in the tank. I'll check that out tomorrow when I have some light, just looking for any other ideas to look at.

thanks

sounds like gunk in the carb to me

I cleaned out the carb this morning, but still no luck. Any other ideas?

It doesn't even try and start with a little tarting fluid down the carb, I'm starting to think ignition system.

I go tit to start tonight, but now it's only running on 4 or 5 cylinders.

Guess I'll be doing a compression test tomorrow. Plug 4 was wet when I pulled it, so I assume that is the missing cylinder.

I really want to get this beast back on the road.

I found a major problem tonight. I did a compression test to get a better look at the status of the motor. 2 cylinders were not getting compression. I pulled the VC off and foudn that 2 lifters were not on the rocker arms. I loosened the adjusters enough to get them back on, adjusted them to specs, but as soon as the motor turned over the popped right back off.

Can I remove the side plate on the passenger side to get a peek at the lifters?

I'm afraid of what I am going to find.

what it sounds like is you stuck a couple of valves, check the height of the valves,most likely there the exhaust valves, start there and see if they are all the same height.

What do you mean by "Stuck"? I've got the rocker cover off I'll go check them.

How do I get them "unstuck"

Other than the valves that are open because of the cam shaft, they all appear the same height.

IT was the #2 intake and #4 intake that jumped the rockers.

PS thanks for the input

If the rods jumped the rocker it is likely they have been bent.

It is very common for old gas to cause the valves to stick. If the valves stick the pushrods will bend.

The good news is the rods can be straightened with a hammer on the driveway, and the engine likely wouldn't know the difference. Make sure those valves aren't still sticking.

If using gas that is several years old... STOP! Drain the tank, remove it and have it cleaned. Replace all fuel lines and filters. If you must try to run the engine before properly cleaning the tank and replacing the lines, use a gas can with a rubber hose going straight to the pump.

Believe it or not, if the lifters are too bent, you can get new ones at your FLAPS. I purchased a pair at Autozone for $3 each.

I did drain the tank completely and replaced the fuel filter before I tried to start. I did not take it out and clean it though. Is it possible to clean the tank, or is it better to just buy a new one? It was running on fresh gas, but I did notice a lot of sediment in the fuel filter after running it for a bit.

I pulled the push rods and rolled them on a flat surface, and they don't appear to be bent. Is it possible to bend the lifter?

I really appreciate all the help.
father and son

I've never seen a bent lifter. If you have a soft faced hammer give each of the valve tips a wrap with the hammer. The valve should move. If not you will notice if you have a stuck valve.
The clean gas is washing the varnish out of the tank and giving you problems. If you can find a radiator shop that still has a hot tank you can maybe get it done, ask a price first. It may be cheaper in the long run to buy a new tank.

have you messed with the dizzy or plug wires prior to this problem... lifters can collapse, sort of strange that both would,
usually they start to making clicking sounds first but..........

check the basic, like firing before you start taking things a part...strange that it would run when you first started and then nothing ...not usually a major problem when that happens

I did get it running again when I got it back to my house. It idles but misses hard when I give it any throttle.

At this pit I'm fairly certain I have two stuck valves. I'm going to play with it tonight and see what happens.

It was idling and running very well before this happened, So I'm pretty sure the ignition system isn't at fault.

it's got to be valves, the valves not closing, put air into the cyl. and see where it's coming out.if you hear air coming out of your exhaust pipe then its a exhaust valve, if you hear air coming out of the carb, then it's the intake valve. unless something went down the carb and is stuck or bent the intake valve my bet it's the exhaust valve.

if you are a lucky kind of guy you can try and remove the manifolds and spray carb cleaner in the exhaust ports and with a soft hammer try and tap the top of the valve to move the valve down and spray while doing this and it might free up, its just varnished up from old gas,...maybe you dont have to take it apart, hope this helps.

I would unhook the gas line and not run anymore of the tainted gas through it.

i forgot to say also to spray the carb cleaner in between the springs and spray the valve thats inside the springs so you can free up the crap from the top and maybe the juice will run down the stem of the valves and set it free, if you have a valve spring tool to remove the springs would be a good idea too, then you can work on freeing it with the spring pressure not there.

thank you guys for all the input, tomorrows agenda is draining and pulling the gas tank.

The two valves are soaking in seafoam and PB blaster tonight and I'll see what kind of action we get tomorrow.

Worst case scenario I pull the head and freshen it up. The truck has been sitting for an absolute minimum of 3 years, likely much much longer. I wasn't expecting every thing to go smoothly.

Would it be a bad Idea if I got it running on 4 cylinders again and ran some seafoam through the top end?

Would it be a bad Idea if I got it running on 4 cylinders again and ran some seafoam through the top end?

It couldn't hurt it any more than it is now... it may not help, but it won't hurt.

Would it be a bad Idea if I got it running on 4 cylinders again and ran some seafoam through the top end? yes! bad no good! you could damage your engine even more if something breaks!

did not realize the truck had been sitting for 3 yrs before you got it running, no wonder it might have stuck valves.. why not just do a valve job and be done with it........

link to some tips about valve adjustment, etc

I believe that's the route I'll be going. Worked on freeing them up for a couple hours last night with no luck.

Where's the best place to get a gasket set.

your Flaps , or vendors that support this site. should not be hard to get...

Heads off and ready to be delivered to machine shop.

probably money well spent, and not that much

Once the valve guides get gunked up with varnish, the only sure fix is to pull the head, remove the valves, and clean the guides with a stiff-bristle brush and carb cleaner. Time-consuming, but effective! Anything short of that risks more problems!
Jerry

Especially when you have friends at a machine shop.

Only took about 1.5 hrs to pull the head.

Just wanted to say THANKS for the advice everyone gave! It's been a while, but I got her up and running yesterday and she purrs like a kitten!

I need to rebuild the carb, as the accelerator pump is shot, but I was able to drive it around the block a couple times yesterday.


PS. I used the eastwood tank restoration kit to clean the tank, time consuming smelly process, but the tank looks sparkling new now!

Here's quick vid of her running
261 first idle

You can also see that I recoated the exhaust manifold with a baked on finish and powder coated the intake manifold.

Had here running for a couple days, and noticed a drip of coolant coming from the back of the head. traced it back to the head gasket. bummer.

Not sure what I could have done wrong.

Do you have to copper coat the head gasket? I followed all the correct torque specs and sequences for the 261. Head was straight with no cracks.

I always spray the head gasket with that copper stuff.

Have you re-tourqued the head after the first few runs? Often the gasket compresses and things settle in.