Need Fuel Pressure Regulator Part # 96 850

Post by **misha** » 05 Oct 2011, 17:43

waynej wrote:...Misha, AutohausAZ has the damper for $48.14...

I know,but shipping to Serbia would be almost the same... 48$for a part +around 30-35$ for a shipping.

On a '96 & '97 it should be under the back of the car around right rear wheel(in fuel filter area).It depends on what engine menagement you have,Motronic 4.3 or 4.4.

For Motronic 4.4 it should be in a fuel filter area and for Motronic 4.3 it is attached at fuel rail(where fuel pressure damper is on Motronic 4.4).

waynej · Post by **waynej** » 06 Oct 2011, 20:32

Thanks guys, I found the FPR by the fuel filter near the LR wheel. The vacuum line to the FPR was T'd off a main line going farther back. I have had a code for a long time that said "Evap leak, gross leak" and I have not been able to find the leak. I think they must be getting the vacuum for the FPR from the Evap system. This would explain why my fuel pressure is too high at idle but does not respond to manifold vacuum and therefor is too low at more than 1/4 throttle. Now I must find that vacuum leak. Does anyone know what it is at the rear of the vehicle that is involved with the Evap system? Besides the charcoal canister is there anything else involved with the evap system? Is there any common place the vacuum lines tend to break? I have checked most of the lines under the hood but I can't see all the way to the canister.

caz2773 · Post by **caz2773** » 06 Oct 2011, 23:01

check the hoses at the charcoal canister(drvr side frnt fender), check purge valve connections(radiator shroud), check line from purge valve to fuel tank(hard plastic line from puege valve that goes under the block to pass side underside through a plastic cover that extends to rear pass side to fuel tank), check lines at the fpr(next to the fuel filter), check lines at the roll over valve(plastic white valve by the fpr has 2 rubber connecters) the roll over valve was the spot for my p0455 evap leak relaced the rubber and no more codes this is a code that is the biggest pita to find

Post by **erikv11** » 07 Oct 2011, 07:18

On my car it was the J tubes on top of the charcoal canister. The canister was located up under the fender.

Here is a pretty thorough discussion with pics:
http://volvospeed.com/vs_forum/topic/97 ... rge-leaks/

waynej · Post by **waynej** » 09 Oct 2011, 20:41

Thanks guys, found the leak quickly after reading your advice. The short rubber hose to the rollover valve was broken completely off. Replaced hose - no more codes. Still have extreme shortage of power. Fuel pressure stays at 43 psi. Does not go down upon start up and does not go up at full throttle. I guess this means I need a new fuel pressure regulator?

waynej · Post by **waynej** » 15 Oct 2011, 18:22

Thanks for the info, checked everything and found the leak. The short rubber line to the rollover valve was broken completely off. Replaced the line and still have no vacuum to the fuel pressure regulator. The line starts at the manifold and goes to a round device, mounted on the fan shroud, but no vacuum at the other end. The electrical connection to this device has a constant 12V and a flashing ground. When it's plugged in and I'm looking into the vacuum connections there is no movement and when putting the stethoscope on it I hear nothing. I bypassed this device and put manifold vacuum directly into the system and now if I disconnect the line to the FPR there is the vacuum hissing sound but it won't move a vacuum gauge. Pinched off the vacuum line just aft of the FPR and rollover valve-no difference. I will do more checking up front. In the meantime I'm thinking that having 43 psi on the fuel all the time instead of less at idle and light throttle could not be causing the extreme lack of power(takes 2+ miles to get up to 65MPH), it probably just increases the fuel consumption.

Does anyone know if a MAF sensor can be bad without setting a code?
Does anyone know of anything else that could cause this extreme lack of power?

Post by **erikv11** » 15 Oct 2011, 20:09

No comment on the fuel pressure, maybe someone else can help you. OK one comment: these potentially small differences you are talking about, seem very unlikely to be an issue. But I am no expert on fuel pressure, no doubt ...

MAF can be bad without setting a code, definitely. But you can test the MAF very easily - just unplug it. The ECU will go into a default mode for A/F that is not good long term, and a CEL will be set, but if the MAF is the problem then the car should run better in default mode.

Most common lack-o-power cause: vacuum leaks.

Is your car a turbo or NA?

Post by **misha** » 15 Oct 2011, 20:28

waynej wrote:Thanks guys, I found the FPR by the fuel filter near the LR wheel.

If it's by the fuel filter it should be near the right rear wheel.

Can i ask you to post a picture of your fuel pressure regulator which is near right rear wheel(in fuel filter area)?

I would like to compare it with what i have in fuel filter area.

waynej · Post by **waynej** » 16 Oct 2011, 14:55

Thanks Erikv11, My car is NA. Tried driving with MAF disconnected, it might be a little better but close to the same. If I disable the EGR it gets much worse, has almost no power. I dropped the canister from up under the fender so the top is visible. J tubes are good all connections are good and tight and no cracks anywhere. There is a rubber tube going from the canister up over the wheel well but it doesn't come out anywhere. Where is it supposed to go? Is there any valves inside the canister that could malfunction and block vacuum going to the rear of the car? What is the purpose of the purge valve on the fan shroud that is blocking all the vacuum to the Evap system? Is there any danger in bypassing this valve and having vacuum to the system all the time? On my 96 the vacuum line goes from the purge valve to the canister and then to the rear of the vehicle. A previous reply said the line goes directly from the purge valve to the FPR at the rear. Is my car plumbed wrong?

[b]Does anyone know of anything else that could be causing this extreme lack of power?
[/b]
P.S. The problem is much worse on hot days.

waynej · Post by **waynej** » 18 Oct 2011, 18:14

Had more time to work on car, removed purge valve and old disintegrating rubber hose and ran new hose from manifold to plastic tube. Have full vacuum to canister but almost none out of canister. Pinched off rubber hose leading from canister over wheel well, now have full vacuum out of canister and to whole system. Fuel pressure now changes with throttle position as it should. Idle is now unsteady, it hunts between 900 and 1000 and sometimes to 1100 for just a second. Fuel pressure is holding steady at 39 psi at idle. What is this line from the canister for and where does it go? Do I need a new canister? What is the purpose of the purge valve and what happens if I run without it? I wish Volvo had left the fuel pressure regulator on the fuel rail where it had it's own line to manifold vacuum. Running it off the Evap system is very troublesome.

My biggest concern is the extreme lack of power which may have nothing to do with the Evap system. The more throttle- the less power! My 0 to 40 time is 12 seconds with a very light throttle. At full throttle 0 to 40 is 37 seconds! In first gear it won't go over 3400 RPM so you must let off on the throttle to get a shift. In second gear the limit is 3000 Rpm. In third gear it's even less. All this is the same with the MAF connected or disconnected.

I hope there is someone out there who knows something about this problem. It has been 2 days since my last post and no response. Thanks in advance for any help you can give.