1275773 Fuel Pressure Damper NLA

850oldschool · Post by **850oldschool** » 18 Apr 2021, 19:30

I figured out why my car starts like it's flooded every time. Apparently the diaphragm in this fuel pressure damper has ruptured. It has a vacuum hose which connects to the vacuum tree and it's now possible to suck fuel right through the vacuum hose. It seems this part is unique to 96 NA's since my 97 NA has a different style damper without a vacuum hose attached to it. This is also NLA.

I found a couple of used fuel rails on ebay which have this part still attached, but I'm wondering what would happen if I just capped off the nipple on the vacuum tree and plugged the hole.

Or maybe somebody has a new one sitting around for a car they got rid of?

Post by **scot850** » 18 Apr 2021, 19:38

Try here:

http://www.new-part.com/product/bosch-f ... -1997-1996

Neil.

850oldschool · Post by **850oldschool** » 18 Apr 2021, 19:52

scot850 wrote: ↑18 Apr 2021, 19:38 Try here:

http://www.new-part.com/product/bosch-f ... -1997-1996

Neil.

Yep, I was jumping up and down when that turned up in my search results. Unfortunately that's on old version of their website which is still online. When I went to pay I got directed to the current website, where neither the Bosch or Volvo part numbers were anywhere to be found.

I see that the Pierburg 72243801 (Volvo 1275658) is still readily available. It looks like I would need the 9497492 "striker plate" to go with it to hold it in place? I can't really tell from the diagrams what keeps it from popping out of the fuel rail like a champagne cork.

Post by **scot850** » 18 Apr 2021, 21:18

That Bosch part number comes up on a few web-sites in UK and Europe. Not cheap but may be available there. Good Luck!

Neil.

Post by **erikv11** » 18 Apr 2021, 23:37

Volvo 1275658 is not an option, it is an FP damper not an FPR. Cars with the damper also have an FPR but the FPR is located elsewhere, either on the steering rack or back near the fuel filter.

I might have a spare one but I can't check until Tuesday, PM later this week if you want me to look.

Best bet is junkyard or erievolvo.com etc. Used factory Bosch unit preferred over aftermarket. Similarly an eBay rails is not a bad idea if the price is right, these don't go bad very often. The vacuum line should be mostly free of fuel odor if the diaphragm is intact.

Post by **misha** » 19 Apr 2021, 03:03

850oldschool wrote: ↑18 Apr 2021, 19:30 I figured out why my car starts like it's flooded every time. Apparently the diaphragm in this fuel pressure damper has ruptured. It has a vacuum hose which connects to the vacuum tree and it's now possible to suck fuel right through the vacuum hose. It seems this part is unique to 96 NA's since my 97 NA has a different style damper without a vacuum hose attached to it. This is also NLA.

I found a couple of used fuel rails on ebay which have this part still attached, but I'm wondering what would happen if I just capped off the nipple on the vacuum tree and plugged the hole.

Or maybe somebody has a new one sitting around for a car they got rid of?

Fuel pressure damper does NOT have a vacuum line!

What you have on fuel rail is fuel pressure REGULATOR!

850oldschool · Post by **850oldschool** » 19 Apr 2021, 08:04

Here's what I think I know so far. Up until 95 the fuel system had a return line, and the regulator was on the fuel rail, modulated by a vacuum line connected to it. Then in 96 they changed to a non-return fuel system and replaced the regulator with a damper. For some weird reason they retained a vacuum connection. Then in 97 they changed the fuel rail again and converted over to the Pierburg part I mentioned above, which was used for many years.

I believe I can convert to the non-vacuum damper if I can find either a 1275792 fuel rail or the one which superseded it, 1270568, which was used all the way up to 2004 on convertibles, turbo and non.

It's not hard to see why they abandoned the vacuum connected damper after only one year. When it fails (as it has on mine) the intake manifold is slurping unmetered fuel through a straw.

Post by **Sveedy** » 19 Apr 2021, 08:49

So inquiring minds want to know: How do you tell the difference between the two, other than part # ?
I have a '96 Turbo which I thought had the rail mounted FPR.

850oldschool · Post by **850oldschool** » 19 Apr 2021, 09:16

Sveedy wrote: ↑19 Apr 2021, 08:49 So inquiring minds want to know: How do you tell the difference between the two, other than part # ?
I have a '96 Turbo which I thought had the rail mounted FPR.

My cars are NA, so I didn't study the turbo stuff carefully. But from what I know so far, if you have a fuel return line, the FPR is on the rail, and if you don't have a return line the FPR is back by the tank and there is a damper on the rail. Volvo does a great job of confusing you by providing only one parts diagram, which shows the return line system with FPR on the rail.

Post by **misha** » 19 Apr 2021, 10:39

You have a fuel return line even if you have fuel pressure damper at fuel rail.
It's just near fuel filter area where FPR is or some models have it around steering rack.
So return line is THERE.

Do what you want,but you CAN'T install FPR instead of damper at fuel rail or damper instead of FPR without proper fuel rail and without EVAP system modifications.

To clarify some things....
N/a models up to '95 had FPR at fuel rail.
'96 n/a ...some have fpr...some have damper depending on engine management.

'97 ALL have damper at fuel rail since all '97 n/a 20v (B5254S)are M4.4.

FPR have vacuum line

Damper doesn't have vacuum line