Case 580C fuel starvation

[silverstr8p]

Starts and runs fine, but then seems to starve. Was running fine after fixing clogged fuel lines and tank, but then started trying to starve the more I run it. I temporarily ran external fuel tank tied 4 feet up ROPS so plenty of gravity flow.

Replaced filters multiple times and cleaned all fuel lines. Also, removed fuel inlet to pump and didn't see any debris. What else should I be checking? I don't want to just rebuild the pump unless I can prove it's the pump. Sounds like a hard job swapping a pump (and expensive).

 

[Billrog]

Vented ?, How long does it run before before starving?

 

[thepumpguysc]

Pull the return connector on top of the top cover..
It might have a checkball and spring in it..
If the pump is coming apart internally, the connector will be partially clogged..
Hold the connector up to a lite, u should be able to “see thru” it..

 

[silverstr8p]

@Billrog yes, I created a temporary tank out of a cranberry juice plastic jug, cap slightly unscrewed for venting.

It idles for a few minutes then dies, sooner if you rev it up. Couple days ago it ran and drove just fine, but we've been debugging since original tank was clogged with rust and we cleaned it out after huge amount of effort. That's why we used the temp tank to eliminate tank issues until we got it running well.

@thepumpguysc I'll try to get in there and look, thanks!

 

[MG84]

To add to what thepumpguysc said, check the entire return line from the injection pump to the tank. Maybe even take it loose completely at the pump and run a temporary return into a jug. My 480E was acting like it had fuel starvation issues but it was actually the return line being plugged so it couldn’t get the excess fuel out of the pump. Symptoms were very similar to starvation. Plug was in the fitting on the bottom of the tank from rust and gunk in the tank.

 

[thepumpguysc]

A lot of times, the broken flex ring bits will accumulate in the corner of the small side cover window..
If u take the window off and hold a wad of paper towels under the window while it drains, u can usually find a bunch of little black bits..(mouse turds) THEN look in the corner of the window for more..

 

[silverstr8p]

Thanks all, will take a look!

How hard is the pump to rebuild if I decide to? I think the rebuild kit is like $40. I've rebuilt engines and put airplanes together, is this within my reach, or should I find someone to do it?

Is there anyone on the forum that sells this service?

 

[thepumpguysc]

Engines r easy.. but have u ever built a watch.??
I’ve got about 37years building pumps for a living..
I’d be happy to help you out..
U save a couple hundred and I get to hone “my skills”..(lol)
U can reach me on here by clicking my screen name and send me a private message..or. Put my screen name “at aoldotcom” in your home mail service..
There’s no shortage of “happy” customers on this site.. all ya gotta do is ask..

 

[T-town]

The Pump Guy is the best you'll find. Will fix your pump, and give you all the important info you'll need to get the pump off correctly..... and back on.
Don't think you would find a better deal.....

.... all sorts of folks on here would say the same.... a search would bring those up.

Good luck!

 

[thepumpguysc]

Thanks T-town..

 

[Honcho]

There is a dirt or debries clugg in the tank . take tha tank ff n clean it.

 

[Honcho]

There is a dirt or debries clugg in the tank . take tha tank ff n clean it.

 

[silverstr8p]

Okay, took off the covers, here's what I got out of it, tiny little black pieces, probably a mix of rust, gunk, and who knows what else.

Cleaned things out a few times. Each time I did, the 580 ran a little better, but would eventually starve for fuel. Is the pump officially done, or something else?

 

[thepumpguysc]

The little mouse turds are pieces of the broken plastic flex ring.. it’s done..
The more u run it, the worse it’ll get and eventually the engine will rise in rpm’s and you won’t be able to shut it down..
It’ll start surging first.. it won’t just run-away without warning..
If THATS any consellation..??

 

[thepumpguysc]

What ur calling starving for fuel.. is actually the return getting stopped up..& if u can’t get fuel out of the pump, u can’t get any more in..so it shuts down..
I hope that makes sense..

 

[stinky64]

Removing and replacing the pump is not that difficult if you're pretty mechanically inclined, rebuilding said pump by yourself is not advisable unless you're extremely mechanically inclined and have an awesome set of tools. Besides the $40 rebuild kit your gonna need a new pilot tube pressed in and an upgraded governor weight basket to eliminate future "mouse turd" issues . Oh then you're gonna need a second rebuild kit for when you rip one of the o-rings from the first kit upon reassembly. Then there's the dreaded cam advance screw that can snap off if you're not careful. If you have no clue what any of these parts are or not completely confident in your ability, hook up with Pumpguy he'll save you some loot and heartache and will also school you on pump removal and installation. Disclaimer: not a paid spokesperson

 

[thepumpguysc]

Lol… it’s a dam good thing I don’t hafta pay for spokesmen .. I’d be broke..
U guys r great.. thank you..

 

[silverstr8p]

How hard is it to get these things out? Just unbolting the shaft from the gear and undoing the pressure lines, or do I have to speak Swedish and have fingers the size of needles or something? Hoping I can get it out in less than a day

Any steps I should "definitely avoid"?

 

[thepumpguysc]

Shut off the fuel or pinch a rubber line.
Remove the side cover and let the pump drain.
Inside the window you’ll see a stationary line.. there’s also one that rotates..
Rotate the engine by hand in the correct normal rotation until the 2 lines meet AND STOP..
Now pull off the lines and linkages and the 2 or 3 nuts holding the pump to the block..& wiggle the pump back..
The drive shaft will stay in the engine.. & your pulling the pump over the shaft..
I find it easier to loosen and/or remove the lines AT THE INJECTORS..because u have to have the room to pull the pump back off the drive shaft..
U can pull the pump without timing it 1st.. BUT.. it’s 100x easier to get it back on if u time it 1st..
This is a RoosaMaster/Stanadyne pump.??
If it’s a CAV/DELPHI PUMP, ignore the above instructions..

 

[stinky64]

A crescent shaped box end wrench is very helpful for the nut on the stud at the back of the pump.