Stanadyne/roosa master injection pump

rockcity

rockcity

everyday is a chance to get better
Joined
Apr 10, 2005
Location
Greenville, NC
Anyone familiar with these injection pumps?

Dozer keeps cutting out and I have a fairly newer replacement pump so the rubber weight retainer should be updated. And I removed the glass ball check valve to keep the pump from over pressurizing.
Dozer cuts off after about 20 minutes then fires up after I relieve pressure. Not sure what the continued issue is…


@jeepinmatt
@braxton357
 
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I dont have any useful knowledge on this one. Do you run it WFO or mid throttle?
 
WFO like everything else. Duh. :lol:





But really, I’m at a bit of a loss. The pump over pressurized, usually due to the return line check valve clogging up with remnants of the old plastic weight retainers that fail. This pump is newer so it should have the updated metal one. And I removed th check valve, so it “shouldn’t” overpressurized, which causes the pump to stop working.

I removed the return line and made sure it was clear. The only other thing I think that might cause the return line to plug up is maybe the fitting at the bottom of the tank. I didn’t/couldn’t remove tbat easily, so I didn’t mess with it. I’m kind of hoping that fitting is plugged up so I can get back up and running. Aside from that, I’m at a loss with this pump.
 
braxton357 said:
Is there a transfer pump or is it gravity fed? When you turning engine over with the return line unplugged does fuel come out?
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There is a transfer pump but it looks like someone added it in at some point. The IP is below the fuel tank, so I’d imagine from the factory it was probably gravity.

And yes, fuel does come out of the return while cranking and running.

It will run great for about 20 minutes. Then shuts itself off like it’s starved for fuel. Bleed down the pressure on return or injector line and it starts and runs great, for 20 minutes until it dies it again.


I’m still wondering if there is something blocking the return line, at least partially. My next step is to run a long flex return line back to the tank through the fill cap and see if there is some obstruction in the stock line that I’m missing when I try to clean it.
 
Well damn. Temporary return line doesn’t seem to be the resolution. Line is open and allows for free flowing return of fuel to tank, so that isn’t the issue. Something else is causing over pressurization of the IP and it cuts it out after about 15 minutes of operation.

Now I’m lost. Time to trouble shoot even more I guess.
 
Is the lift/aux pump still running when it gets hot? We had an aux lift pump on a skid steer that would get hot and stop working causing similar symptoms. Would rarely ever do it in the winter but as soon as the outside temp was above 70 I had issues every damn day til I replaced the pump.
 
StretchASU said:
Is the lift/aux pump still running when it gets hot? We had an aux lift pump on a skid steer that would get hot and stop working causing similar symptoms. Would rarely ever do it in the winter but as soon as the outside temp was above 70 I had issues every damn day til I replaced the pump.
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The electric pump feeding the filters and then the IP is still running when it dies, at least I hear it running. I haven’t pulled a line to verify but I hear it running.

I’m tempted to replace the IP but it’s a $900 part, so I’m a little hesitant to just replace parts for the hell of it without really thinking and trying to find the issue. I’m betting it’s something simple I’m overlooking.
 
I have an 50 horse intl tractor in Alabama that I dicked with for 3 years... Was gravity feed. Added a fuel pump, new fuel lines, finally new injection pump. It would run great pto speed for 20-40 minutes then would completely lose power. Anyway long story short it was a piece of garbage in the fuel tank would randomly fall into the fuel pickup that was on the bottom of the tank and starve it.

Try pulling fuel from a Jerry can instead of the fuel tank.
 
Still tinkering. Spent the weekend helping the wife with flower beds and deer prevention, so will trouble shoot on Monday.
 
My 304cr Caterpillar excavator was doing about the same thing, I checked and replaced everything from the tank to injection pump. it still would run for about 10 minutes and it would die under a load. i even had 3 diesel mechanics and a cat mechanic check it out and called there expert and couldn't tell me what was wrong with it. Finally pulled the injection pump and sent it to a pump shop to get it checked out. The barrels and looked like little pistons were worn out and when the pump or fuel was cool it would run decent when it started to warm up it the fuel would get thinner and lose pressure and die under a load. $1400.00 later for the pump rebuild it runs better than it ever did.
You probably need to get the pump checked out by a shop.
 
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After replacing both of the large napa fuel filters I was still having issues. Found this inline edelbrock filter tucked up under the seat and well, you can see the outcome when I pulled it.

$12 for a new one and it’s been running well for the last 2 hours. Probably a lot of trash in the tank, so I suspect this filter will continue to give me a fit for a while until I run a few tanks of fuel through it (and probably several filters) and hopefully flush most of it out.


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