Advice, please: where to fit an inline priming bulb?

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NealB

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The little manual priming lever on the fuel lift pump doesn't seem to do anything.

I realise there's a number of possible reasons why (and, yes, I've tried the easiest one of turning the engine over to change the cam position).

I've got a rubber bulb type primer lying around, and was thinking of fitting that.

Where should it go, please?

Options:

1 between tank and separator (this is gravity fed anyway, so I guess no point putting it there)?

2 between the separator and the lift pump (would it be able to push the fuel through the lift pump, and on to the filter?)

3 between lift pump and fuel filter?

4 between fuel filter and injection pump?

Thanks for any words of wisdom.
 
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Any of 1 to 3 would work, assuming your gravity head is enough to conveniently bleed the first filter ("separator") and so the pump isn't required for that. 4 would tend to suck air in through the second filter's bleed screw instead of pushing it out, so don't do that.

All else (convenience of access, etc) being equal, I'd choose 1 because:

- it means you can bleed the first filter more positively
- depending on the design of your engine, you might be able to bleed the whole system without opening any screws at all, just pushing the air all the way round and back down the return line. Not all engines allow this.
- obscure use, but if it's sucked flat you know the dip pipe from the tank is blocked. Best combined with a vacuum gauge tee-d off the line between first filter and lift pump to show if the first filter is blocked.

Pete
 
B
Where most convenient I would think bearing in mind it needs to go before anything that will need it for bleeding.

But i suggest you look agin at the priming lever on the pump, esp with regard to the positioning of the cam shaft. If the pump works in practice it is difficult to believe that the priming lever wont operate it but they don't pump vast volumes per stroke
I
 
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Generally close to the tank. They are much better at pushing diesel than sucking air.
I assume your separator has a filter in it?
You use the bulb to push diesel in, while the bleed screw lets air out.
If you try to suck the air out, that air has to come out elsewhere so you will be pumping a lot of diesel and air out of the bleed screw on the engine filter.

The main thing is to be able to reach the primer bulb and the bleed screws at the same time, even if that means using your foot to pump the bulb.
Personally, I'd look at raising the separator so the primary filter can be changed without the line to the lift pump draining back. Then you should just be able to bleed the separator and be going again after a filter change.

You should find that once you've used the bulb to push some fuel into the lift pump, its priming lever will work fine.

The down side is the bulb see unfiltered diesel. If that's a problem clean the tank?
I think if you fit a bulb, carrying a spare is a must.
 
langstonelayabout said:
I thought this too on my Beta 20, turns out that I wasn't pushing it down firmly enough. Once I did, it squirted diesel nicely and enabled priming of filters with ease.
Click to expand...

I found this with my Beta, it had about another 5mm of stroke and this was where it pumped the most.

I placed my primer bulb after the CAV filter but before the lift pump, firstly so I could bleed from the top of the lift pump and secondly it was right at the front of the engine so very easy to get to when you need it. I have no problems drawing diesel/air through the CAV.
 
OK thanks for the tips so far.

I'm going to nip over to the boat (thankfully, only a minute's walk away).

I'll try being a bit more macho with the lift pump lever (it'd be great if langstonelayabout turns out to be correct).

I'll then try, yet again, turning the engine over to a different position (though I've done this countless times already).

Then I may as well try fitting the bulb primer (between water separator and lift pump will take about 5 minutes to fit).

If none of that works: I'll try swearing in a more seamanlike manner.
 
Yellow Ballad said:
I found this with my Beta, it had about another 5mm of stroke and this was where it pumped the most.

I placed my primer bulb after the CAV filter but before the lift pump, firstly so I could bleed from the top of the lift pump and secondly it was right at the front of the engine so very easy to get to when you need it. I have no problems drawing diesel/air through the CAV.
Click to expand...

Thanks .... just before I dash off, so the bulb pushes fuel through the lift pump quite happily?
 
Dismantle the lift pump, (take the lid off?) clean and check. My ford has two possible designs, one if the diaphragm fails would allow fuel into the sump.
 
I have a primer bulb that sits on top of the fuel tank. Installed a new Beta 14 last winter, along with new filter / separator and fuel lines. When it came to starting for the first time, just squeezed the bulb until the return line into the tank stopped making bubbling noises, turned the key and it started. No cracking open injectors or faffing with filters. OK it did splutter for a few seconds, but overall a simple and effective solution.
 
The plot thickens.

I tried to push the lift pump lever further: sadly, no cigar, there.

I turned the engine over, one more time, and tried the lever again: no luck.

I cut the fuel line between the water separator and the lift pump, and fitted the inline primer bulb. On pumping that, the bulb is absolutely hard.

I disconnected the fuel line at the lift pump, and the bulb squirts fuel nicely through the line. So there's fuel from the bulb to the 'in' side of the lift pump.

So ..... it seems as if there's a blockage in the lift pump itself.

I've just nipped home to raid the Mrs' make up box for a small mirror, to try to see how to get the lift pump off (there's no space to get my head in a suitable position). It feels like just two bolts, but it seems a bit crowded around there: getting a socket or spanner on will be 'interesting'.
 
The lift pump is definitely blocked.

I by passed the lift pump, connnecting the bulb primer straight to the filter.

As soon as I squeezed the bulb, air, then fuel, squirted through the loosened bleed screw at the injection pump (there isn't a bleed point at the filter).

I kept squeezing, and, after a few turns of the starter...... she fired up and ran. Luvvly jubbly!

Next problem is removing the lift pump: space is very tight, and there's various hard bits of engine that'll make getting a socket on the bolts very tricky. I'm off to find a very thin walled 10mm socket.

If that fails, I'm wondering about the viability of fitting an electric fuel pump.

I'll start another thread for recommendations.
 
If your engine is a Volvo it may have a filter in the steel feed pipe that is attached to the fuel pump. My 2030 has.
Hope this helps.
 
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