Lift Pump Fault BV1505

[JDR]

I started the boat the other day and the engine died after ten minutes.Fuel OK to lift pump but nothing getting to filter.Lift pump bypassed and engine ran OK. Lift pump blown through, put back on and works Ok, lifts fuel to filter when pumping lever but engine only runs for half an hour before being starved of fuel again.

 

It is a sealed unit with no access to take apart. Can the lift pump be faulty but still work on the lever when manually pumped? Is it time to sell body parts and get a new lift pump from Beta?

[RLWP]

What does the pump look like?

 

MORE: Like this?:

 

 

http://www.ebay.co.uk/itm/GENUINE-KUBOTA-05-series-mechanical-diesel-fuel-pump-16285-52032-V1505-D1105-etc-/321155639669?pt=LH_DefaultDomain_3&hash=item4ac65e2975

Richard

Edited April 25, 2014 by RLWP

[JDR]

Small circular housing for diaphram, arm with a spring facing engine, manual lever on bottom.Fuel line in from tank and line out to filter on top.Will try and get a picture.

[RLWP]

Check my post again, I have amended it

 

Richard

[magnetman]

My mum had a BV1505 in her narrowboat. Lift pump failed after someone stepped on it (mechanic). One of the pipes cracked where it joins the main body so it sucked air. they are not replaceable so a whole new lift pump was fitted.

Edited typographical error

Edited April 25, 2014 by magnetman

[JDR]

Check my post again, I have amended it

 

Richard

Yes that's the pump.

[RLWP]

That's your marker then. £40 on Ebay, plus £7.50 postage

 

I wonder if we can find it for less

 

Richard

 

MORE: This one: http://www.ebay.co.uk/itm/Genuine-Kubota-mechanical-fuel-pump-Assy-16285-52032-Transfer-Pump-brand-new-/321388872184?pt=UK_BOI_Industrial_Tools_Generators_ET&hash=item4ad44501f8

Edited April 25, 2014 by RLWP

[JDR]

Well that's 90 beer tokens less than Betamarine, thanks.

Edited April 25, 2014 by JDR

[RLWP]

Did you see my second listing?

 

 

Richard

[JDR]

Did you see my second listing?

 

 

Richard

I did, thanks again getting better. Do you think the pump is definitely u/s?

[RLWP]

Could be, the test where you bypassed it is a good indicator

 

I have seen one of the other common Kubota pumps where the delivery valve had split, causing erratic running

 

Other possibilities are a floating thing in your fuel tank that gets onto the fuel pipe inlet. Or no fuel...

 

Richard

[JDR]

Ok thanks, I was fairly certain the pump was faulty after bypass but confused by pump working ok on lever. It's the obvious thing to change so that's what I'll do.Will report back but may be early next week.

[nicknorman]

It does seem a bit odd that when manually pumped it works OK, but not when pumped by the engine. What does it feel like when you pump it manually? The engine presumably has a cam/pushrod arrangement to operate the pump. I suppose it's feasible that there is something up with that bit, though it would seem unlikely. It would however explain why it works OK when manually operated.

[RLWP]

It does seem a bit odd that when manually pumped it works OK, but not when pumped by the engine.

 

I agree, except it's not really the same thing. If the pump is 'sort of' delivering, it will do it's job OK with a stationary engine but perhaps can't keep up with the running engine

 

It is odd, and without being able to open up the pump what can you do?

 

Richard

[nicknorman]

Thinking aloud, is said cam on the camshaft? In which case the stroke rate is quite fast. So a very sluggish return spring / sticktion might result in a negligible stroke when pumped fast.

[RLWP]

Thinking aloud, is said cam on the camshaft? In which case the stroke rate is quite fast. So a very sluggish return spring / sticktion might result in a negligible stroke when pumped fast.

 

A worn lever on the pump can lead to a short stroke

 

My money would be on a dodgy valve, but without a saw we will never know

 

Richard

[JDR]

Lift pump replaced, symptoms exactly the same.Fuel comrs out of the bleed screw for the first filter closest to the tank (CAV filter with a water drain).Took that off to have a look and bowl at the bottom was full of cherry red clean diesel.Engine filter also clean.

 

I now suspect an air leak somwhere between lift pump and tank.How dore somebody of only moderate mechanical ability test the fuel lines for pressure integrity?

[RLWP]

With difficulty

 

When the engine starts to hesitate, is there air in the filter?

 

Something else to do, start at the tank outlet and check every joint with a pair of spanners to make sure it is tight. Work from the tank to the engine and back down the spill line.

 

This is an effective method and can save a lot of puzzling. I recently forgot this and spent an hour trying to find an air leak at the stop tap (that I had created)

 

Richard

Edited April 29, 2014 by RLWP

[JDR]

When the engine dies there is air in the filter.Once fuel is manually pumped to filter using lever on lift pump the engine starts easily and runs for half an an hour before stalling again. Will do what you suggest tomorrow but right now I am eyeing a bottle of Cillit Bang wondering if it contains alcohol!

[RLWP]

You've definitely got an air leak. Sorry for misleading you on the fuel pump

 

Richard

[nicknorman]

We have a BV2003 which is obviously a different engine, but a similar one. When running, it can cope with a fairly major air leak at the fuel inlet because any air pumped into the injector pump is separated and returned to the tank as part of the throughput of fuel.

 

So I although there may be a bit of an air leak, I am still suspicious of the activation of the fuel lift pump. I believe this can easily be checked though. The lift pump's manual lever is returned to its rest place by a small spring. When the engine is not running, operating the lever not only has to overcome the spring, but also move the diaphragm and pump the fuel. The latter force is significantly more than the former.

 

With the engine running, presumably the pump is being operated by the cam / pushrod. Therefore if light finger pressure is applied to the lever whilst the engine is running, enough to overcome the spring but not the pumping force, the lever will stroke with the cam activation and the length of the stroke can be established.

 

If this is normal, approaching the full travel of the lever, I will go away. If not, there is something up with the pump activating cam/pushrod.

You've definitely got an air leak. Sorry for misleading you on the fuel pump

 

Richard

That may be true, but doesn't really explain why fuel is not pumped into the engine when it's running, but is easily pumped in when the lift pump is manually operated. Yes the engine would be taking fuel but at maybe 1/2 litre per hour at idle that is barely going to make any difference.

[JDR]

You've definitely got an air leak. Sorry for misleading you on the fuel pump

 

Richard

No, thanks for your help and acting as a sounding board, appreciated, that goes for everybody that has chipped in, ta. Edited April 29, 2014 by JDR

[RLWP]

That may be true, but doesn't really explain why fuel is not pumped into the engine when it's running, but is easily pumped in when the lift pump is manually operated. Yes the engine would be taking fuel but at maybe 1/2 litre per hour at idle that is barely going to make any difference.

 

It's normal behaviour for an air leak. The air builds up in the filter over time and is quickly cleared by bleeding the filter. Last time I saw it, it took 2 hours for the engine to stop (which conveniently happened in Gosty Hill tunnel)

 

Richard

[nicknorman]

It's normal behaviour for an air leak. The air builds up in the filter over time and is quickly cleared by bleeding the filter. Last time I saw it, it took 2 hours for the engine to stop (which conveniently happened in Gosty Hill tunnel)

 

Richard

Is the lift pump before or after the filter?

 

On our engine the lift pump is integral with the injector pump and hence after the filter, but I thought on the engine in question it would be before the filter? Therefore I don't see why a functional lift pump would fail to push fuel through the filter and injector pump even if their was a bit of air mixed in.

[RLWP]

Usually before the filter, I would like to see some photos of this installation before speculating further, Diagnosis by forum is fraught with danger of misunderstanding

 

Richard