Fuel pressure regulator replacement procedure

smokeum99ta · May 19, 2020

2012 vw passat tdi 197k . I believe my fuel pressure regulator is going bad. I'm having loss of power and flashing glow plug light. VCDS shows two codes 5216 fuel rail/system pressure and 8784 fuel pressure sensor. So I have a new FPR on the way. Is there a certain way that this has to be replaced or can I just swap it out and go?

oilhammer · May 19, 2020

I would pull the N290 fuel metering valve out of the top of the pump and take a look for metal debris.

pedroYUL · May 19, 2020

You probably need a new High Pressure Fuel Pump...sorry to tell you.

STOP running the car, as the metal flakes will keep circulating and clogging everything

smokeum99ta · May 20, 2020

That's not the news I want to hear but it is what it is. Until then I'm still gonna replace the FPR and go from there. I will check out those things this you'll said.But afterwards is there any special thing that needs to be done after swapping out the FPR to get it started/going again?

oilhammer · May 20, 2020

You can lead the horse to water.....

pedroYUL · May 20, 2020

Your car won't run very much longer, the HPFP is self destroying and according to my reading you are one of the very few lucky ones that gets a code before the car just stops running all together.

You need to clean your system of metal flakes and indeed change the fuel rail, HPFP, fuel filter, at least.

Don't know if a dealer can cover the work as warranty. I know it is covered in my extended dieselgate warranty for both my 2015 ones.

thundershorts · May 20, 2020

It could also be in tank lift pump failing. It would generate same codes.

smokeum99ta · May 20, 2020

oilhammer said:
You can lead the horse to water.....

What's that supposed to mean? Im gonna check out what you mentioned

pedroYUL · May 20, 2020

Listen to Oilhammer. Check for metal and go from there.

If you don't have metal, then move over to lift pump proper function.

smokeum99ta · May 20, 2020

Found nothing on the N290 but pulled the filter and seen shiny particles floating around on the top of it. I'm sure its metal. What should I do from here? Replace HPFP then what? Im sure there's more lol

pedroYUL · May 20, 2020

I have no first hand experience, but if it was my car, my hands, and my wallet:

* Remove all the fuel possible: wipe tank, use the lift pump to push diesel all the way to filter

* Dump the fuel in filter canister, wipe canister

* Remove rail (safely, it's under pressure), try to flush as much as possible with new diesel

* Flush all lines you can using syringe or lift pump...I don't have a good handle of this fuel system as I'm still learning this Common Rail stuff

* Retrofit CP3 pump, and forget about the original pump

* Pray no metal made it to injectors

Perhaps I would start by opening the tank, if you see metal there, it means the HPFP was eroding for some time, and you need a full teardown of the fuel system.

Good luck.

oilhammer · May 20, 2020

You need a new HPFP.

I would also replace the in-tank lift pump, remove the rail and all the pipes on the engine, take the rail pressure regulator off the one end of the rail, and take the rail pressure sensor off the other end. Clean it all VERY thoroughly with brake cleaner and lots of compressed air. Replace the rail pressure regulator and rail pressure sensor. The new pump will come with the metering valve.

Blow the lines to and from the tank and filter assembly out thoroughly. I do not think the CKRA has the little strainer in the plastic bulb on the HPFP inlet side, I cannot remember. If it does, replace that too.

Clean out all the hoses under the hood, one at a time, individually. I would also get the injector return hose assembly as there is a little check valve in there. You *may* still need injectors, but hopefully not.

Install a new filter, prime it, get it going again, then after a few minutes, put a new filter in again, and suck out anything that collected at the bottom of the filter canister.

smokeum99ta · May 20, 2020

pedroYUL said:
I have no first hand experience, but if it was my car, my hands, and my wallet:

* Remove all the fuel possible: wipe tank, use the lift pump to push diesel all the way to filter

* Dump the fuel in filter canister, wipe canister

* Remove rail (safely, it's under pressure), try to flush as much as possible with new diesel

* Flush all lines you can using syringe or lift pump...I don't have a good handle of this fuel system as I'm still learning this Common Rail stuff

* Retrofit CP3 pump, and forget about the original pump

* Pray no metal made it to injectors

Perhaps I would start by opening the tank, if you see metal there, it means the HPFP was eroding for some time, and you need a full teardown of the fuel system.

Good luck.

Thanks

oilhammer · May 20, 2020

And FYI, the rail pressure is released as soon as the key is turned off. So there won't be anything to worry about there, just some spillage (use some rags).

smokeum99ta · May 20, 2020

oilhammer said:
You need a new HPFP.
I would also replace the in-tank lift pump, remove the rail and all the pipes on the engine, take the rail pressure regulator off the one end of the rail, and take the rail pressure sensor off the other end. Clean it all VERY thoroughly with brake cleaner and lots of compressed air. Replace the rail pressure regulator and rail pressure sensor. The new pump will come with the metering valve.
Blow the lines to and from the tank and filter assembly out thoroughly. I do not think the CKRA has the little strainer in the plastic bulb on the HPFP inlet side, I cannot remember. If it does, replace that too.
Clean out all the hoses under the hood, one at a time, individually. I would also get the injector return hose assembly as there is a little check valve in there. You *may* still need injectors, but hopefully not.
Install a new filter, prime it, get it going again, then after a few minutes, put a new filter in again, and suck out anything that collected at the bottom of the filter canister.

I’m a pretty good mechanic but I think I’ll let the shop take care of this. I just ain’t got the time with work cause of this virus stuff. Thanks for your help. I’ll pass on your info to them.

pedroYUL · May 21, 2020

Get in touch with https://www.darksidedevelopments.co.uk/

They sell a drop in CP3 HPFP that solves the problem for good.

smokeum99ta · May 22, 2020

Thanks.

thundershorts · May 23, 2020

Paint strainers are useful for checking if any contaminents remain. Run lift pump and catch fuel from lines into paint strainer to see if anything remains.

thundershorts · May 24, 2020

A lift pump destructing can also send particles of metal into the fuel filter where they are caught before getting to the hp pump. There was a filter on the intake of my lift pump.

pedroYUL · May 24, 2020

I don't feel like playing with diesel lately. How is that lift pump in the CR engines, gear driven, piston?

I have experience with the lift pump in my BEW PD engine, I can't imagine that pump sending metal thru, but maybe I haven't seen enough.

thundershorts · May 25, 2020

The cr lift pump in in tank and when it destructs it sends debris downstream into the fuel filter.

kolll · May 21, 2022

does anyone know what pressure value lift pump has to have ?
2013 passat, ckra engine

pedroYUL · May 31, 2022

My lift pump kicked the bucket. It has been making a very high pitch whine for a while, on-and-off.
Also, some brief engine hesitation when cold, and long cranking sometimes. Acceleration is less than my wife's CRUA GSW, which also indirectly points to a weak lift pump.

Just ordered the part

Fuel pressure regulator replacement procedure

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