[Grifnsqest]

So I got a call from my mom after work Monday. She said her Touareg wouldn't start.

It's got a newer battery and I just replaced the driver's side fuel pump last month, so I was thinking that maybe the passenger side kicked the bucket too. It does have just under 100k miles, FYI...

So when I got to the Touareg, I ran a quick scan and got these two codes:

P2279 - Leak in Air Intake System
P0327 - Knock Sensor 1 (G61) Signal too Low

At first, I kind of ignored them. I figured the knock sensor, if bad, shouldn't affect the start of the engine. It should only cause it to run rough. And a leak, at least as first thought, again would cause it to run rough, but run nonetheless.

I checked out both pumps, just to make sure. Both pumps were running when attempting to start. After checking out some of the forum posts, some were saying maybe the PCV valve is bad. But would that cause a no start situation??


Let me know what you guys think... I'd like to try and get it figured out ASAP, without having to tow it.

Thanks

 

[Spiegelglatt]

From the self study: Effects of a Signal Failure In the event of a knock sensor failure, the ignition timing for the affected cylinder group is retarded. This means that a safety timing angle is set in the “late“ direction. This can lead to an increase in fuel consumption. Knock control for the cylinder group of the remaining knock sensor remains in effect. If both knock sensors fail, the engine management system goes into emergency knock control in which the ignition angle is retarded across the board so that full engine power is no longer available

Looks like MAF failure would also not kill it. In fact there are few things that will. Read the end, it gives symptoms given failure component by component.

 

[Grifnsqest]

Ok... I read through that Study Guide. I LOVE those things!

But, it didn't get me much closer to finding why it won't start. Do the codes listed above mean much to you, as far as a place to start?

I can throw parts at it, if I have to. But, I'd rather not.

Start with a new PCV and knock sensor...? See if that helps...??

 

[kippyman]

The Crank Angle Sensor will cause that as well, my 05 did that "crank but no start", but I thought it would throw a code

 

[Grifnsqest]

Ok... so potentially dumb question here...

Driver's side pump... the one I literally JUST replaced like a month ago... I have the wiring harness plugged into it (I get voltage from two main leads when trying to crank)... I unplugged the outgoing line while trying to crank and nothing came out. The pump isn't working, right? Did I get a bum pump??

 

[Spiegelglatt]

You should be able to hear the Transfer Pump (even feel it working with hand on it) when you turn key like you are starting (but before turning over-like using accessory mode) or open door (if sitting a while). The transfer pump is used to start the Treg...my understanding is once HPFP is working, the transfer pumps death wouldn't kill the motor, but you wouldn't be able to restart! This will not throw code or fault that I know of. This sounds like your mom's situation.

Now regarding the engine speed sensor. This will kill motor while running immediately. It may or may not register a fault (see attached). If it by chance fails during re-start, the motor will not start.

Based on the lack of likely things to prevent restart I am leaning Transfer Pump. Did you replace OEM? Should have a parts warranty...

 

[Grifnsqest]

It's not an FSI motor, for what it's worth. Its an 04 T1 Touareg.

The pump I put in was a Delphi unit. I have its warranty replacement on its way. I just wanted to rule other stuff out, so it's still not stranded without a solution.

Given the lack of pressure at the fuel rail, and no flow out of the drivers side pump when voltage is applied, I'm goin to start there. Unless the passenger side pump could affect the flow of the drivers side...?

 

[Spiegelglatt]

Indeed 2004. Sounds like you have narrowed it down based on no flow with power. Do keep us posted.

At least with the parts warranty there shouldn't be any out of pocket!

 

[Grifnsqest]

Ok... I went back to the Touareg today, with intentions of pulling the "newer" pump. I left both pumps plugged in, and undid the lines. The passenger side pump was the only one that had fuel coming out the top port.

So I pulled the driver's side pump, wrapped it up, and shipped it back.

In the meantime, I unscrewed the filter housing, to inspect the filter. It looks like most of the photos I've seen online. Old and ready for a replacement. But does anyone have a source or part number for JUST the filter?? Seems like everyplace I've seen so far only has the housing + filter.

 

[Grifnsqest]

So I have a sad update...

It still doesn't start. I have two new pumps in there. And when it cranks, I get nothing at the schrader valve. So I'm having it towed to my shop to have them look at it.

I tried playing different things around in my head, based on other searches on here.

One post said something about the battery in the key. I never changed the battery, but I don't get the connection between a low battery and no fuel. I could understand maybe as a theft deterrent. But I would think that the electronics would be cutting voltage to the pumps, preventing start up. But, I have voltage.

Anyway, hopefully my guys can figure it out. So my mom will be driving a rental for a couple days...

 

[Spiegelglatt]

Well, then perhaps the engine speed sensor? No data and it shuts down, most likely wouldn't even run pumps...


If it is disabled from low key signal it would say such, and not turn over period. I grab the wrong key fob and end up locking my imobilizer all the time. When I get the right key it starts right up. No issues.

If it isn't it sure must be something strange...

 

[Grifnsqest]

So we got the ol girl back. We found that the driver's side flange, the one that houses the filter... was cracked and leaking back into the tank. So that's what was preventing the fuel pressure from building.

Sucks, something so simple. But, I'm glad we figured it out.