2013 Phaeto 3D - No Start

walters_c said:

Was driving my Phaeton on way home when i made a stop for about 15 minutes at a store. When i returned to car and tried to start, the engine turns over but not starting.

Below it what i have don so far and the results.

1. Listened for fuel pump action when door opens. Pump runs for a few seconds.

2. Test each pump individually by bridging at relay junction. both fuel pumps were activated.

3. open fuel ling at pressure sensor (G247) and run each fuel pump individually. Fuel sprays out through opening when pump #1 is active. no fuel seen t opening when pump #2 is active.

4. Tried starting car with fuel pump #1 active (bridged). No start.

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Interesting that you have no fuel flow when running pump #2. From many anecdotes, and direct personal experience on older Phaetons (non-FSI), you should be able to start and run the engine on either. A glance at PL24 shows your low pressure fuel pumps to look pretty much the same.

Can you confirm how you identified pump #1 vs pump #2? The primary fuel pump should be on the right side of the car, facing forward.

If pump #2 is dead, you might have trouble starting and running if you're low on fuel (less than 1/4 tank) as the second pump scavenges the bottom left of the saddle tank.

walters_c said:

I thought about KESSY playing tricks hence i checked MVBs

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Historically, on the 3D platform, KESSY won't crank the engine if the key isn't authorized. This should be something different. I suppose it's possible this changed with your FSI engine; modern engines exert finer control over the starting process for emissions reasons. But then you wouldn't have burned out your starter when you drowned your last KESSY.

Yeah and if you happen to need a pump for phaeton I have genuine..............

walters_c said:

Actually i determined the pumps by the relay positions, since that is where i bridged them. Relay position being 5a for pump #1 and 6b for pump # 2 as per WD.

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I feel like I've seen them labeled backwards in at least one place in VW official wiring diagrams, but I can't prove it right this moment.

walters_c said:

It is also interesting to note that i got no fuel at line opening when engine was cranked.

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Mmmhmm. Let's skip all possible confusion: bridge BOTH and see if you can start.

jyoung8607 said:

Mmmhmm. Let's skip all possible confusion: bridge BOTH and see if you can start.

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Will do that when i return home later this evening.

Also saw somewhere that there is a fuel transfer process between tanks. I probably need to look further into that also

walters_c said:

Will do that when i return home later this evening.

Also saw somewhere that there is a fuel transfer process between tanks. I probably need to look further into that also

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Historically, pump 2 (left side of car) runs under three circumstances:

• For a few seconds at startup, to build fuel pressure
• Under high engine loads, to maintain adequate fuel pressure
• When the tank is less than 1/4 full, to scavenge the left bottom side

That logic will be explained in the SSPs. On older Phaetons, when pump #1 dies, pump #2 can build up enough fuel pressure to start and run, but it gets turned off after a few seconds. So, the car does a maddening thing where it'll start and run fine for a few seconds, and then die. A lot of people mistake that for an Immobilizer issue. As for yours, with a FSI engine, the logic and behavior may be a little different. But you can't crank without an authorized key and you have no Immo faults that I'd expect for that sort of problem.

Thanks for info. I have been checking out the SSPs to see what i can find.
Today i bridged both fuel pumps but car still doesn't start. I discovered a large crack in the flex section of air intake hose and did a quick duct tape fix but still no luck with starting. Not sure if that major air leak was there prior to me removing hose to access fuel lines.
Could this have caused a engine flood? How can i verify and resolve?

The purge valve (N80) looks clean.

I also notice that the auxiliary coolant pump runs for a while after i try starting engine.

Could this be speed sensor (CPS) related?

Hey " Walters World " What are spark plugs condition and compression readings and spark?
https://forums.ross-tech.com/showth...to-3D-No-Start&p=149191&viewfull=1#post149191

Car was bought in June of this year from used car dealer. It was serviced (including spark plug change) before delivered to me......or so they say

I will have to come back with compression reading.

Never really had engine hesitation or struggle except for twice when it recorded "intermittent G247 malfunction"

Been trying to do that. This car is much scarier than anything i have owned prior.
I did also try to source that fuel pressure sensor locally but it wasn't available. Ordered it of Amazon and it should be in Jamaica tomorrow.

Don't guess, test mechanical's & electrical outputs where needed..........

Do you have spark?

Do you have compression?

Is intake & exhaust clear?

Is fuel being injected by pulse measured at injector and is fuel present in cylinders?

Do you have measured terminal 15 with DVOM during crank and does RPM ref show when logging VCDS?

Are grounds in order?

Is terminal 30 present with no error during cranking?

Are any controllers running an interference and preventing a function?

JPPSG!

Will go through that list as best as i can. I am no mechanic by any stretch of the imagination and i have very little experience with VCDS. Just a regular guy who don't mind a bit of DIY....especially if its gonna save me some money and get my car back on the road.

Come man get your ass in gear than..........

I have to push you guys, you can do it.

Historically, pump 2 (left side of car) runs under three circumstances:

For a few seconds at startup, to build fuel pressure
Under high engine loads, to maintain adequate fuel pressure
When the tank is less than 1/4 full, to scavenge the left bottom side

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That is true for the W12 engines. However, pump functions are reversed for other versions of Phaeton (like mine).....Pump #2 (left side) is the primary pump that runs constantly (as per SSP).

Interesting that you have no fuel flow when running pump #2. From many anecdotes, and direct personal experience on older Phaetons (non-FSI), you should be able to start and run the engine on either. A glance at PL24 shows your low pressure fuel pumps to look pretty much the same.

Click to expand...

I discovered that the supply hose from left side (primary) pump was disconnected at the "Y" connector on the right side of tank. It was obviously removed previously and not properly affixed. This explains why there was no fuel flow when pump was running. Fuel was just being dumped into right side of tank. It also explains the lack of start when right side (secondary) pump was bridged, as line was open and enough pressure was not being generated for engine start.


I have since reconnected supply hose from left side pump and car is now starting.


Thanks to all for the support and very informative posts.