Case IH 495 Sporadic Power Loss

[koop]

My 1991 Case 495 developed a sporadic power problem today. RPM's would drop even at full throttle and sometimes even stall and then power would return. The problem seemed less prevalent if the RPM's were kept closer to idle.

It seemed like a fuel delivery problem so a checked the two fuel filters by opening the drain cocks. The first one drained fine but when I opened the second, I first heard air (going in or out, I could not tell) then nothing. Then after some time a drip then after more time fuel poured out as it should.

Is the filter shot or am I drawing air in the system somewhere??

Any insight would be most help

Thanks everyone for your help.

 

[gerard]

Sure sounds like air in the fuel line. Mine did that when my wife ran it dry and I had to bleed the system and get the air out. Try changing the filters (if they're partially plugged they may be able to supply enough fuel at lower rpms but can't when the engine needs more fuel at higher rpms) then go through the purging process for that tractor.

 

[banjodunn]

Sounds to me like you have got a blockage in the system the air you can here as you crack the drain is probably vacuum and that is why it is taking a long time for the fuel to get out i would be undooing all the fittings on the fuel lines one at a time and check for any foreign matter start at he tank and work your way forward. Also would not hurt to check tank breather not sure if you have a breather in the fuel cap or small line on the fuel tank it may be blocked

 

[Yankee Clipper]

koop,

I remember a check valve in the fuel system on those rotary Bosch pumps on Neuss built diesels. If it was trashed up and allowed flow both ways, tthe engine would run out of fuel like you saw and then the air would come back to fill the void.

I don't have the manual anymore but your local dealer parts department would have the system onlline where you could see it. The check valve is fairly cheap as well.

Good luck!

 

[David-Davies]

koop,

I remember a check valve in the fuel system on those rotary Bosch pumps on Neuss built diesels. If it was trashed up and allowed flow both ways, tthe engine would run out of fuel like you saw and then the air would come back to fill the void.

I don't have the manual anymore but your local dealer parts department would have the system onlline where you could see it. The check valve is fairly cheap as well.

Good luck!

Koop

Their is a flex hose from the left fuel filter to the injector pump. If this hose fails you'll have all the symptoms, you have. I have a IH 454 [same tractor just a lot older] I had the same problem, a new hose fixed it. What kind of oil pressure do you have on your engine? I have a turned crank and bearings, new oil pump, liners ect. I have only 5 psi at idle and 30 psi at full RPM. with 15-40 oil.
David-Davies

 

[RickB]

Koop

Their is a flex hose from the left fuel filter to the injector pump. If this hose fails you'll have all the symptoms, you have. I have a IH 454 [same tractor just a lot older] I had the same problem, a new hose fixed it. What kind of oil pressure do you have on your engine? I have a turned crank and bearings, new oil pump, liners ect. I have only 5 psi at idle and 30 psi at full RPM. with 15-40 oil.
David-Davies

Your cam bearings are probably shot.

 

[RickB]

My 1991 Case 495 developed a sporadic power problem today. RPM's would drop even at full throttle and sometimes even stall and then power would return. The problem seemed less prevalent if the RPM's were kept closer to idle.

It seemed like a fuel delivery problem so a checked the two fuel filters by opening the drain cocks. The first one drained fine but when I opened the second, I first heard air (going in or out, I could not tell) then nothing. Then after some time a drip then after more time fuel poured out as it should.

Is the filter shot or am I drawing air in the system somewhere??

Any insight would be most help

Thanks everyone for your help.

Change both fuel filters. While you are at it, check the fuel flow from the tank to the primary filter head, then after installing a new primary filter, check flow to the secondary head. After installing the new secondary filter, check the flow at the injector pump. Simple stuff first. These tractors are prone to plugging the tank outlet and tank balance tube with debris.

 

[David-Davies]

Nope cam bearings ar fine. All checked out at the machine shop

 

[David-Davies]

Rick B
You got me thinking, about those cam bearings. If I were to remove the inspection plate for the can and lifters, and I put a dial indicator on the cam shaft some how, then pryed the cam shaft up, would it show the bearing clearince?