B7 V6 fuel pressure issue

[99_FGT]

So my b7, that I've had for just over a year now and hasn106k on the clock, died a couple of weeks ago. Short drive to the shops, first the epc light and a little bit of surging, then again on the drive home, this time with a CEL and no power.
Scanned it at home, came up with p0087 low fuel pressure (first) followed by p0088 high fuel pressure, reading at 125 bar. Timing angles on both showed zero.
Back and forth with mechanic, and confirmed the high fuel pressure issue was the result of a faulty valve on the hpfp. Replaced hpfp, but it didn't make it 20km before it came up with the p0087 again. Seems to be OK if I keep the revs in 2k to 4k, but I'm not game to drive it on anything but surface streets in the left lane.
Interesting that, when there is a hard ecu fault, the timing is locked to zero. Both are now showing at limit. No symptoms before: no rough starts, no lumpy idle, no whistles.
Mechanic has had the car for a week now and I still am none the wiser as to what it is. He was chasing down a low pressure fuel pump issue, but until I go back on Monday I won't know where he's at.
Checked pcv, all good. Rechecked hpfp, old one same issue and new one no (low or high) fuel pressure errors on a cc v6.
I've got no reason not to trust the mechanic, but I'm not getting answers, and we're both getting frustrated. The car has been undriveable for 5 weeks now, and I'm at the point I'm going to buy a new car and bench the v6 until I can diagnose it.
I like driving it, but I just don't trust it (ps. hopefully the hpfp leading to it running rich was the cause for the high fuel consumption, the last few tanks it got so bad I started driving it like a camry)
Any similar issues? Or thoughts?

Sent from my SM-T835 using Tapatalk

[kamold]

Check measuring blocks for cam phasers in the ECU.
Could be a damaged guide. HPFP can be out of time while everything else is still OK.

[99_FGT]

Measuring blocks are at limits, showing up as 7.something degrees now, but nothing and no symptoms earlier

Sent from my SM-T835 using Tapatalk

[kamold]

Would be looking at chains and guides.
I had a B7 with 90k on it the guide nearest the HPFP was in about a hundred pieces all in the sump and pickup. The chain was hard up against the metal guide pin so it kept the rest of the engine in time but fuel pump was out by 90 degrees.
Replaced chains and guides and she ran like a dream again.

[MIG]

Last VW club of VIC meet-up, I had a great chat with a shop owner who works on many VR6s down here in VIC; I got some great pointers about walnut blasting etc.

One topic we chatted about was when to do the timing chains on the BWS, and if there was a good way to predict when to do it, he said the timing measuring blocks tell you about 50% of the time, and the number one way of knowing they are due, is a logged message about the HPFP, as once they get out of time the pressure peak does not match the injector firing order.

As Kamold said above, he also mentioned that when doing the chains and guide, always pull the oil pan, as there will be guide pieces in the pickup screen.


I am getting ready to order the parts because even tho I change my oil every 10kkm, I am nearly @ 150kkm, and I don't think it will be long now, 106 km is a bit low in km but not unheard of.

[99_FGT]

Mechanic has asked me to come in, pretty much resigned to needing to do the chains, most likely cause is shat a guide.

Sent from my SM-T835 using Tapatalk

[Gerzos]

Hi mate.

I had these 2 error codes. Timing guide was broken... was getting a really harsh jerk on hard acceleration. The chain was basically jumping/slapping around

1. Low pressure fuel regulation - p310a - fuel pressure fluctuates.

2. Fuel Rail/system pressure - p0087 - too low - intermittent.

Take care.