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Fuel Pressure Regulator

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

This topic is in the MVS Volvo Repair Database » Fuel Pressure Regulator
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cowboysvolvofan
Posts: 34
Joined: 8 December 2009
Year and Model: 850, 1994
Location: South Dakota

Volvo Repair Database Fuel Pressure Regulator

Post by cowboysvolvofan »

Hi everybody. In addition to tackling codes this weekend, I recently noticed the smell gas inside and outside my 850. I popped the hood and noticed a slow leak from the fuel pressure regulator. I disconnected the vacuum line, which NOW, I know was a big mistake because after reading the Chilton's manual, it tells me to relieve the pressure before disconnecting anything. Well... anyhow, the line looks good, no cracks or holes. I believe the leak is coming from the top of the regulator. Either way, its in a spot where I can't tell exactly, but the gas builds a small pool.

Do any of you have any experience with this part? Any suggestions? Thanks.
1994 850
182K

Ozark Lee
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Post by Ozark Lee »

You should never have any fuel outside of the FPR. Was there fuel in the vacuum line? If so the diaphragm on the FPR has ruptured and it will cause the car to run very rich and also lead to flooding. When the diaphragm ruptures it basically forces raw fuel into the intake manifold through the vacuum tree.

This becomes a priority 1 repair if it is bad. The plus side is that they don't often fail so a used one from a junk yard is an option if money is tight.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

cowboysvolvofan
Posts: 34
Joined: 8 December 2009
Year and Model: 850, 1994
Location: South Dakota

Post by cowboysvolvofan »

I noticed there was fuel around the vacuum line, but could not tell for sure if there was any inside it. It's definitely running rich. I believe it has failed. The safest bet is to just change it. I believe the fuel is definitely coming from the regulator.

I'm going to get on that asap. Thanks a lot!
1994 850
182K

raykan
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Post by raykan »

Hi cowboysvolvofan

I have the similiar problem with my car. There is a gas leakage around the fuel pressure regulator.
Have you solved your problem? What did you do? and how did you do?

How can I take apart Fuel Pressure Dampers and may be injectors?

Thanks in advance

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misha  
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Post by misha »

Here is procedure for replacing fuel pressure damper(i hope it's the same with fuel pressure regulator):
Attachments
fuel damper 850,s,v,c70.pdf
(25.59 KiB) Downloaded 2227 times
'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

raykan
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Post by raykan »

misha wrote:Here is procedure for replacing fuel pressure damper(i hope it's the same with fuel pressure regulator):
I checked the document, but don't I need to release the pressure before unsecrew the gas line(6)?

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misha  
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Post by misha »

Yes,you need to release fuel pressure from valve at the end of a fuel rail.It's located between numbers 2 & 3 at the picture from document.You can use a towel or something to catch remaining fuel from the rail.
'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

raykan
Posts: 59
Joined: 17 December 2009
Year and Model: 1998 S70 GLT => 236K
Location: CA
Been thanked: 1 time

Post by raykan »

I took apart all the injectors and the gas pressure modulator. My problem is a gas leakage and I think it is comming from around the modulator. I tried to find the seal for the modulator but unfortunatelly Volvo dealers doesn't sell that part alone and they are not same with injectors o-rings.
I replaced all o-rings of injectors, and put everything back. but there is still leakage.

cowboysvolvofan
Posts: 34
Joined: 8 December 2009
Year and Model: 850, 1994
Location: South Dakota

Post by cowboysvolvofan »

Sorry raykan, I have not.
We're just getting over a blizzard.

Is there leakage every once in a while, or everyday? I ask b/c mine seems to only leak when I fill the gas tank. This may be just my imagination, but it doesn't leak all the time. I do feel it is coming from the regulator, and the part is about $50 from Auto Zone, so I'm going to start there.
1994 850
182K

cowboysvolvofan
Posts: 34
Joined: 8 December 2009
Year and Model: 850, 1994
Location: South Dakota

Post by cowboysvolvofan »

I just came in out of the cold from replacing my Fuel Pressure Regulator. Only took me about 20 minutes to actually do the work, however, coming inside to warm up made this an hour long job.

I've included some pictures. I didn't think about taking pictures until I was about to put everything back together, forgive me, but at least I got something. :)
1994 850
182K

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