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N/a 240: Walbro 255 fuel pump questions

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Yarbles
Posts: 4
Joined: 6 October 2012
Year and Model: 240 1991
Location: Nc USA

N/a 240: Walbro 255 fuel pump questions

Post by Yarbles »

I need to replace at least one fuel pump; buzzing main pump and occasional stalls; so I'm considering the Walbro 255 in-tank pump to do the job of both.
Will I need to replace any other parts? Will the pressure regulator be ok with a higher pressure supply? There's an HP version for $10 more which I'm considering in case of future turbo upgrade, would there be any issues using that?
Oh and finally, what's the thing next to the main fuel pump slung under the car? Looks like a fuel filter but I seem to remember it being downstream of the pump..
Lots of questions I know but I'm trying to get my head round how the whole system works so any info appreciated.
Thanks,
Yarbles.

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billofdurham
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Post by billofdurham »

Welcome to Matthew's Volvo Site.

I'll answer the easy one first: the thing next to the fuel pump is the filter.

Volvo 740s with the Regina fuel system do use only an in-tank pump and the series 1 Volvos used them. Without knowing pressure specs I wouldn't be prepared to commit myself.

Bill.
Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
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1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

Yarbles
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Joined: 6 October 2012
Year and Model: 240 1991
Location: Nc USA

Post by Yarbles »

Well I saw a graph showing the Walbro sustaining 80-100 psi at the flow rate I'm expecting but I don't know about the stock pump. I'm wondering if the Walbro could give more pressure than the regulator can handle and cause it to fail.

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billofdurham
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Post by billofdurham »

My information shows the stock pump to be rated at 4.5 - 5.3 bar or 65 -76 psi.

The book also shows that the fuel pressure must not exceed 84 psi.

Bill.
Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
1984 244DL, Manual, Beige.
1987 744GLE, Manual, Green.
1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

jimmy57
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Post by jimmy57 »

The under car pump is a long-lifer but the in-tank low pressure stage pumps are crap. The undercar main gets loud when the in coming fuel is foamy from failed in-tank pump. IF you do the two stage in-tank with a walbro it will be loud and you will have issues on how to get the plumbing done to attach the now high pressure hose to the fuel filter. You will need to replace the hose from tank all the way to fuel filter as that is not a high pressure hose from factory.

Yarbles
Posts: 4
Joined: 6 October 2012
Year and Model: 240 1991
Location: Nc USA

Post by Yarbles »

Do you know if the noisy Walbros were rubber mounted at all? I read that they're a smaller diameter so need some kind of sleeving to mount them..
For the pressure issue I've seen adjustable universal regulators for not too much money. Should that take care of everything?

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