# Waukesha 310 fuel issue



## mlappin (Jun 25, 2009)

So about a month ago was running the vertical tub grinder with the 1755 and I noticed it was dropping RPM's. Grabbed a few fuel filters and changed em then it ran fine, for awhile. Have checked the entire fuel system, not sucking air anywhere and it has a full stream of fuel to the injection pump. Even pulled the primer pump apart, it's fine, uses the same one as both my Perkins 354.4 that my Whites have, both of those one of the poppets came unseated, one would just miss wide open and the other just plain died immediately.

Problem is this, and it did it again yesterday, RPM's drop off from 2400 to 2000 and even under no load sounds rough like it's missing or starved for fuel, notice more smoke as well. Now for the strange part, shut it off for 5-10 seconds, restart it and it runs just fine for days or even a few weeks. At first I thought it was a heat issue as in pump is about shot, but it restarts immediately, I've had a few Roosa-master pumps in the past that were wore enough of you shut em off hot you had to wait on em to cool off to restart. That isn't the issue here.

I'm thinking internal governor? Something is wore enough on a real hard pull something comes out of alignment, shutting it off lets the springs pull whatever is acting up back to where its supposed to be?


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## PaMike (Dec 7, 2013)

Algae in the fuel tank that starts getting sucked in and clogging up the intake? I kinda doubt it on a tank that draws out the bottom like a tractor, but I had this happen to a skidsteer that had a draw tube pulling out of top of tank.

Might be worth a check in the tank...

Mike


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## mlappin (Jun 25, 2009)

I have a full flow of fuel to the injection pump.

Haven't had algae issues in years and the one time we did it the transfer tank was the culprit, this tractor is filled straight from the storage tanks and no other tractors have any issues. Also wouldn't explain the shut it off and start it up then its fine.


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## Gearclash (Nov 25, 2010)

I'm going to guess you have a Roosa Master pump and that the leak off return for the pump is plugged. Usually it is the check ball fitting screwed into the housing of the pump, but it can be the tank return fitting as well. The problem originates from a disintegrating governor damper ring that produces debris inside the pump. To test, remove the check valve fitting and run the engine using a catch pan for leak off fuel. If the engine runs normally, that is your problem.


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## mlappin (Jun 25, 2009)

Problem is, soon as you shut it off to remove that fitting, it will run normally once restarted. I know the fitting your talking about I think, has a tiny check ball and spring in it?


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## Gearclash (Nov 25, 2010)

Correct on the fitting. Also correct that if the fitting is plugged the engine will restart just fine, might even run decent for a while, then will lose power and or quit. Depends how plugged the leak off is.


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## Gearclash (Nov 25, 2010)

BTW, the debris in the fitting will be trapped between the spring and the barrel of the fitting. The only way to get that crap out is to use a small piece of welding wire with a tiny bend in the end to massage the spring, and occasional air gun use. If the ball doesn't seem to travel freely in the bore, there is crap behind the spring. FWIW I despise these pumps.


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## mlappin (Jun 25, 2009)

Gearclash said:


> BTW, the debris in the fitting will be trapped between the spring and the barrel of the fitting. The only way to get that crap out is to use a small piece of welding wire with a tiny bend in the end to massage the spring, and occasional air gun use. If the ball doesn't seem to travel freely in the bore, there is crap behind the spring. FWIW I despise these pumps.


I take it the cavity of the pump actually gets pressurized since the bleed off can't bleed off?


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## Gearclash (Nov 25, 2010)

The pump body is supposed to have a small amount of pressure in it, which is the purpose of the check valve. If the pressure rises beyond what the check valve generates, first the timing is affected (shows as unburned fuel), then the fuel delivery is increasingly reduced until the engine quits running. Stopping the leak off flow on a Roosa pump will just as surely kill the engine as stopping the fuel supply.


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## glasswrongsize (Sep 15, 2015)

I listened to Gearclash on a Roosa Master pump on my skid steer and he was right on the money. Also Tx Jim gave a helpful point: if you take a screw(s) loose on the timing plate (mine was held on my two standard slotted screws), it will let the back pressure bleed off and will run fine. That is something you can do without shutting the tractor off when it starts to die.

My understanding can be refuted, but I see it as there is fuel going to the little pistons in the pump and when the check valve gets blocked, the pressure builds to equilibrium inside of the pump and the fuel doesn't flow into the pistons any longer and doesn't move...or doesn't move as much. My pump is due for a rebuild, but (for now) I have taken the check valve completely out; it's probably not recommended, but I just needed to limp it until winter when I should be able to do without it longer.

Mark

PS, this video really helped me get my head wrapped around the problem.






PPS, the check ball is opaque and I didn't have my glasses on when I first pulled it apart; I held it up to the light and could see through it. Therefore, I thought Gearclash and TxJim were mistaken about my problem...they were not! The ball gets crud around it and behind it and can't move enough, but you can still see daylight through it.


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## mlappin (Jun 25, 2009)

Okay, gotcha, too much internal pressure restricts the travel of the spring loaded pistons. Kinda how our 903 cummins works, more pressure the charge pump delivers the farther the internal pistons move in the injectors before being activated by the rocker arm.


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## mlappin (Jun 25, 2009)

Gearclash said:


> I'm going to guess you have a Roosa Master pump and that the leak off return for the pump is plugged. Usually it is the check ball fitting screwed into the housing of the pump, but it can be the tank return fitting as well. The problem originates from a disintegrating governor damper ring that produces debris inside the pump. To test, remove the check valve fitting and run the engine using a catch pan for leak off fuel. If the engine runs normally, that is your problem.


We have a slew of those roosa master pumps on the farm, I think all the Waukesha's have em, one oddball has a Bosch I think. Even my 354.4 Perkins have em as well as both our JD loaders.

Even more annoying, we have like four 3208 Cats on the farm, in the space of two or three years we replaced three of em, they'd sit as little as a week then refuse to start. Zero smoke no matter what you did, the internal rack would stick in the off position. No matter how much fartin around you did they'd stay stuck in the off position.


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## Gearclash (Nov 25, 2010)

The scary thing about those miserable Roosas is that they morphed. There are a number of slightly more modern variants of them that are just as perfect at turning diesel fuel into an obnoxious haze. Strangely, one of the names is Lucas, some of which pumps were used on 5.9s in Case construction equipment and CIH Maxxums. I never hated an injection pump until those things came into my life. There should be federal funds available to replace them with Bosch P-pumps.


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## mlappin (Jun 25, 2009)

I must be lucky then eh? Have 8 of em on the farm atm and for the most part don't have issues with em.

As much as people hate em and bash em, I have four Cat 3208's as well, 3 in tractors and one in a grain truck. The one in the grain truck has been running since 2001, I remember that clearly as it did have a gas engine, I shoehorned the Cat in, I remember it quite clearly as I was laying under it building an exhaust system when the wife came out and told me the first plane had hit the World Trade center.


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