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850 T5 - Running issues post fuel-pump replacement

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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misha
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Year and Model: '97 850 2.5 20v
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Re: 850 T5 - Running issues post fuel-pump replacement

Post by misha »

Pinch the return line of FPR while testing the fuel pressure on the rail.
If fuel pressure rises it is not the pump.
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

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Cookeh
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Post by Cookeh »

Thanks Misha, got a pair of pliers on it and squeezed progressively until it was practically closed. No pressure rise.

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misha
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Post by misha »

At this point....the fuel pump is faulty.
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

User avatar
Cookeh
Posts: 522
Joined: 14 January 2019
Year and Model: 1996 Volvo 850 T5
Location: Ceredigion, Cymru
Has thanked: 77 times
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Post by Cookeh »

Pulled the Walbro out before giving it the two fingered salute, and stuck a Bosch in. All works perfectly now, nice to see Made in the USA still carries the same heft it used to. It is borderline infuriating that I spent a over a week of evenings trialing everything bar the pump, only to find out its DoA. Makes the £20 premium for the Bosch seem entirely insignificant now.

Thanks for the help, all.

850oldschool
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Post by 850oldschool »

I hope I don't jinx myself by saying that I've gotten about 7 years of service out of my Walbro and that last week I measured it delivering 42 PSI.

Where was the Bosch pump made?

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abscate
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Post by abscate »

Pulled the Walbro out before giving it the two fingered salute,
Cultural translation for the colonies. That’s a peace sign turned around , with the palm facing towards you.

The American translation is the same thing with the index finger folded down

:lol:
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Cookeh
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Post by Cookeh »

850oldschool wrote: 07 May 2021, 16:27 I hope I don't jinx myself by saying that I've gotten about 7 years of service out of my Walbro and that last week I measured it delivering 42 PSI.

Where was the Bosch pump made?
I too hope you arent jinxed too! I certainly seem to attract more than my fair share of bad luck with these things, in fairness. Bosch was made in Ger.

Thank you, abscate, for the translation :mrgreen:

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