Case 500 has a dead cylinder

Larry

This is apparently the same engine that had (has?) the pushrod oiling problem in a thread down the page. Was the valve lash way out of adjustment when you got this? Was the oiling problem present when you bought this, or after some work had been done? 15 lbs at anything other than hot low idle is pretty low pressure.

Without knowing the history, it's very difficult to eliminate anything at this point, because God only knows what the last guy might have done....

Fuel coming out the manifold and fuel in the oil are from a non-firing cylinder(s?), which you already know is #3, and probably NOT an injector problem now that we know you had the problem before and the injectors have been rebuilt. Insufficient oil to the head could cause major valve problems very quickly. I think I would do a compression check or just go ahead and pull the head off #3 and take look.

Good luck.

Larry

This helps. Oil pressure is ok.

To check compression, you will need either a special adapter to insert into the injector opening, or you can make one from a bad injector - remove the innards then braze a fitting onto the external side that you can hook to a compression gage.

Curious that decreasing the valve clearance may help compression - both valves have this effect? The only thing I can think of offhand that would cause that is a flat cam, but something may come to me in a dream later on.....

Larry

Yes, the book does say to check the powrcels whenever you have injector problems, but I have no experience with them. (IT book does explain the procedure). Maybe someone else can tell us more....

The only problem I see with checking compression through the powrcel hole is that you'll be changing the volume of the cylinder by pulling the powrcel.

My gut feeling is that the last guy may have had something apart and put it together incorrectly. Simply because that seems to have happened a lot in my experience.

And yes I'm over 40!

Larry

That's another possibility although I'd expect misfiring on both #3 and #4 and that apparently (?) is not the case. A compression test would narrow things down quite a bit...

Larry

If the gasket were bad between cylinders, you would expect to have poor compression on both. If it were bad between the cylinder and the water jacket or an oil passage, you would be burning antifreeze (white smoke) or oil (blue smoke). Finally, if the gasket were bad between the oil and water passages, they would be mixing. I don"t think the head gasket is a likely problem in this particular "case" based on what you"ve told us although anything is possible....

One other thing you might check is the lift on the push rods (compared to those on one of the other cylinders). I"m still intrigued by your comment that the cylinder seems to miss less if you decrease the valve lash (a dangerous thing to do, by the way....).

Good Luck,

Larry

Good news, sounds like a valve job on one head will probably get you running.

BTW, I recall a discussion of some tricks to getting the powrcels out - you might want to search the archives....

Larry