VW is acting up again.

So it seems time for the Passat to throw it''s semi-annual hissy fit and give me grief. Tiger Mom comes home Saturday and tells me that the CEL is on (surprisingly my VW never has a CEL, must have burned out). I get out the trusty HF scanner and it tells me that it's code "P2294" Fuel pressure regulator 2

Huh. Well, maybe let's see. I clear the code and run it up the street to fuel it up (she had it down to about 1/8th of a tank). CEL comes on immediately and if I lean on the throttle more than a tiny bit it misfires and the CEL flashes. No bueno.

Get gas and return car to garage. Today I dig out the fuel pressure regulator I had laying around (I know, right? It had thrown this code a couple years ago so I bought it then but the code went away so it's been sitting on a shelf ever since).

No love. Hard starting, stumbles off idle, CEL returns after clearing. Something isn't happy. I'm gonna clean the MAF and replace the fuel filter cause neither of those things has ever been done to my knowledge.

What else should I do? My diagnostic skills suck, I can replace a part but metering and voltage drops, etc make my brain skitter off into the corner singing "lalalalala". Probably why it took a year to get the Ranger running right.

Oh, the car in question is a 2007 Passat 3.6 with 115,000 miles on it.

Time for a fuel injector service?

How much fuel pressure does it have?

If the regulator didn't help, then i'd check the pressure and try a fuel filter if it's low.. if that doesn't fix it, then you probably need a fuel pump..

Go to the parts store and rent a fuel pressure test kit, that will rule out the fuel pump. The FSM will have the test procedure and pressures.

In reply to BrokenYugo: Flying Spaghetti Monster?

Also, I just stopped at the parts store. It doesn't look like this car has a fuel filter.

Factory service manual. In absence of that, google "year make model fuel pressure", it's probably been posted somewhere.

Also, I just stopped at the parts store. It doesn't look like this car has a fuel filter.

A quick look on Rock Auto shows that the pump, regulator, and filter are an integral unit, conveniently located ... in the tank. Yay for you :(

My guess? She ran it low and picked up some gunk.

Try changing the fuel filter(s) and verify fuel pressure.

If that is okay, then try to find a way to verify fuel volume via fuel pressure gauge taped to the hood for a short drive, etc.

Edit: after re-reading the above posts, I change my answer to "take it out back and shoot it"

FSM available here - although not cheap

My BMW has the pump and filter in the tank, and those crafty Germans the filter is also the pressure regulator, so the "filter" costs about 10 times what a filter should cost.

Does the tank have a top access hatch? That makes it a little easier.

 Recommend: replace all that stuff in the tank, pump and filter, the filter might also be the regulator, if not replace that as well.   For less than $50 go buy a pressure gage test kit, check the pressure before doing the work and after.

 Then there is the possibility of air leaks, which will cause a lean run.  Also the injectors could be a issue, but first make sure you have the required flow and pressure or the rest of it won't have a chance to work.

I replace the Fuel Pressure Sensor (G247) since I had one laying around. Put the scan tool on it and got some readings.

From a dead cold start it ran VERY rough and poorly for the first 45 seconds or so. Then abruptly cleared up and idled near perfectly. If you gradually lean on the throttle it will pick up revs ok but if you floor it, it stumbles badly.

FRP(psi) reading bounces around at 88-95 but drops to mid sixties during that above mentioned flooring it.

CATEMP seems high at 900F

So it seems likely that it's either the fuel pressure valve (maybe some schmutz got in it and is clogged) or the high pressure fuel pump is bad. Buddy of mine (Midas shop owner) suspects the pump. But I'd like to get a better diagnosis before throwing a $220 (Rock Auto) pump at it that takes 3-5 hours to replace.

Any words of wisdom?

Stefan (Not Bruce) wrote: Edit: after re-reading the above posts, I change my answer to "take it out back and shoot it"

I do not wish to be perceived as an insensitive arse, but that's the funniest thing I've read today!

So it's not like a Honda Civic whereby access to the fuel pump is through the floor under the back seat?

Unfortunately you are probably looking at a high pressure pump failure. Sometimes it's just the low pressure pump struggling to feed enough volume to the high pressure pump too.

If you have access to a Vag-Com you can check the duty cycle of the electric pump. Should be at about 50% at idle, anything 70% or higher means the pump is failing.

In reply to NEALSMO: That's good info to have, thanks!

In reply to 1988RedT2: I know, I laughed too. Unfortunately I need to have this car on the road for a couple more years yet. And no, nothing is particularly easy to work on.

All I have to add is Volkswagons Suck ass. Yes I own one, wish I didn't. Worst car I've ever had.

In reply to D2W: Agreed. But I'm kinda stuck with it for a while yet.

Just ordered the high pressure fuel pump. Wish me luck.

From the title, my first thought was the company was acting up again

After reading the posts, maybe it was.

Three simple steps to solve the problem.

Step 1.) Open hood, locate radiator cap and remove.

Step dos.) pull new car that doesn't originate from GErmany or a german company under the cap.

Step trois.) Throw away old cap.

other than that, I have nothing. My one and only condition on working on cars: No German cars. Ever. Keeps my blood pressure lower and my wallet fatter.

Owning 2 and servicing MKIV's professionally really burnt me out on modern VW's. The build quality and reliability just took a massive dump in that generation. They've improved since then, but that's a pretty low bar to compare them to. Owning one past warranty is not a gamble I'm willing to take.

I still LOVE MKII's though.

Alrighty kids, progress update. Tonight I pulled the old high pressure fuel pump and installed the new one. Started the car and she acted stumbly and roughly the same as before. My friend suggested we disconnect the battery and let the system do a "relearn" so we did that.

Smooth start. Smooth idle. No CEL. No codes pending. Then the test drive.....

As long as I stay below 50% throttle it's fine. As soon as I dip deeper there is a very definite feeling of unhappiness in the engine. Perhaps fuel starvation? Our thought is to pull the fuel pump next and see if the screen/filter is clear. If no then find a VAG-COM tool and get it scanned.

I'm glad I went ahead and replaced the high pressure pump, apparently they go bad frequently enough that it was a good idea no matter what. I'd like to get it running right though. Any other ideas hiverino?

Monitor the low side fuel pressure during this part throttle stumble?

Well E36 M3. I tried to pull out the fuel pump (whole rant here about working with a very full fuel tank) and have succeeded in taking a car that ran albeit poorly to an inert object. Apparently das Germans built a network of interconnected hoses and lines inside the tank that do not want to simply come out through a 6" hole. I very nearly lost my E36 M3 fighting with it and am 100% certain I won't be able to put humpty berkeleying dumpty back together again. Goddamn VW engineers, I wish you all a lifetime of syphalytic rashes on your hootuses and fleas on your dogs!!

Well the new in tank fuel pump arrived. I installed it today with much cursing and knashing of teeth. (Really is the most jackassed design of all time).

Aaaand it exactly the same. Still throwing the P2294 code. Still starts, idles, and drives at low throttle settings. Get into the throttle more than about 50% and things go to E36 M3, crackling, sputtering, loss of power, generaly E36 M3ty behavior.

I believe I'm out. It goes to the shop Monday. $450 in parts to not fix the damned thing.

Plugged cat(s) from previously bad fuel pressure pushing excess fuel into exhaust?

The cats are perhaps 5 months old. And no code being thrown for that.