Injector pump not pumping to 2 injectors

[msponer]

My injector pump barely dribbles fuel from two of its output ports. It pumps vigorously to the other two injectors, and the engine starts immediately and runs on those two cylinders. Above idle it sounds normal, but under way there's a lot of vibration, black smoke, and diesel in the exhaust.

So far I've:
- Cleaned the needle valves on top of the injector pump.
- Run the engine with the two high pressure fuel lines off to confirm that fuel barely flows out at idle. At high RPM there is more flow, but given the black smoke, I'm not sure its enough to get the two cylinders firing.
- Replaced fuel filters.
- Had injectors checked.

Should I try anything else before replacing the injector pump? I thought these things never break...

This is a Yanmar 4JH2E with less than 1000 hours on it.

[a64pilot]

Any good Diesel shop can rebuild one, to be truthful I've never had one apart, always thought it need more expertise and equipment that I have, but I've had several re-built.
I'd go the rebuild route as opposed to new. At least you know the problem, that is 99% of the work right there

[DougR]

Take the injection pump to a diesel injection repair facility to be checked. Most likely the pump plungers on the two cylinders that aren't putting out fuel are gummed up to the point that the return springs can't return the plungers all the way back down to the cam lobe, so each stroke is really only getting a partial fill. That's the normal cause of your described scenario.

Of course there could also be other internal problems, but the shop can tell you that.
DougR

[capt jgw]

I took the pump off my Universal 5411 to the local diesel injection shop. They replaced a couple of springs, cleaned and tuned it and tested the nozzles for $200. Replacement cost would be over $600. Money well spent.

[msponer]

Thank you, guys, for confirming what's probably wrong. It seems to make sense but I wanted you all's opinion, to be sure I wasn't missing another possibility.

We are in Carriacou, so the plan is to fly a replacement into Grenada, get it through customs (ugh), then put it on a ferry to here. The closest diesel shop capable of rebuilding this is either Trinidad or Martinique-- so sending this one out on a round trip to be rebuilt can be chaotically slow and expensive.

Do you think there could be a problem with my fuel, that caused this? I hate to fix it and then kill the next injector pump with bad fuel. If that's possible?

Thanks again.

[a64pilot]

It could be fuel, dirt and or "bugs" in the fuel, but then of course that means it's gotten by two filters, pretty unlikely, but possible

[Xthewater]

Water does a number on injector systems. It will get past the filters and causes seizing in pumps and injectors.

[Lancerbye]

After spending 1300 CAD for a major pump rebuild, for a 34 year old pump, I was told by the experienced specialist, that the major reason for pump problems, on older model pumps, is lack of lubrication by the diesel formulation that was changed some years back when low sulphur was introduced. For older model pumps a lubricant has to be added.

[Starblossom]

I recommend without any reservations the following shop for either fuel injection pumps or turbochargers.

I have used them many times over the years

give them a call to discuss your problem or get a quote to rebuild if needed

great service and reasonable prices

good luck
Diesel Power and Injection
305 592 7070
7741 NW 53rd St.
Miami, Fl. 33166

[Horus]

On my VP 2040 there are shims under the high pressure pump. You have to check if any other pump can be mounted without measuring the thikness of the needed shims!?
Reuse of your pump might be better.


Pump leakage of fuel to the carter of the engine can blow your engine while running. So take care of this. Is your engine oil level oke (not to high?)

[capt jgw]

Originally Posted by Horus

On my VP 2040 there are shims under the high pressure pump. You have to check if any other pump can be mounted without measuring the thikness of the needed shims!?

Right. The shims adjust the pump timing, and if you change the pump you'll need a set of shims to retime it. Rebuilding or tuning the pump should not require retiming, at least mine didn't.

[msponer]

So a pump with the same part number has to be adjusted for a specific engine?

The local mechanic suggests we sail to an island with better facilities and have the pump rebuilt. He says we won't hurt the engine running it slow (~1800 rpm) on two cylinders for a short while to get into the harbor.

So we are thinking of a ~350nm reach to St Maarten in the prevailing 10-20 knot trades.

[capt jgw]

Originally Posted by msponer

So a pump with the same part number has to be adjusted for a specific engine?

The local mechanic suggests we sail to an island with better facilities and have the pump rebuilt. He says we won't hurt the engine running it slow (~1800 rpm) on two cylinders for a short while to get into the harbor.

So we are thinking of a ~350nm reach to St Maarten in the prevailing 10-20 knot trades.

Yes. Each one is individually timed with the shims. The tolerances are too tight to make them interchangeable without shims.

[seabreez]

Before you take anything apart. I would add 1 litre of transmission oil in the fuel tank and run this for some time to see if this will lubricate the pump and injector. We had to do this with a number of diesel engines to swell up seals to prevent leakage and other diesel engines to help with the black smoke. This is due to the no lead removal in the fuel. Let me know if you try it and the results. Thanks Roger

[shakey doug]

How long had the motor been sitting prior to problem? Did you find any water or range silt at Filter change?