Golf not starting

[Jimbob]

So the Mk6 2.0 Golf wont start today.

we have a P2296 - Fuel Pressure Regulator 2 Control Circuit High - Intermittant and no other engine codes.

Got about an 80 mile range left, so fuel 'should' be ok.  Battery voltage is fine.

Just cranks, doesnt sound like its trying to catch.

A bit of digging has taken me to the High Pressure Fuel Pump, and a guide to change it https://www.youtube.com/watch?v=w6W19K40mpk
But not 100% sure on the diagnosis.  Any ideas to prove thats the issue?  Ive reseated the connector on the top of it, but thats it really.

Id pick one up locally...but these.  https://www.autodoc.co.uk/car-parts/fuel-injection-pump-high-pressure-pump-12903/vw/golf/golf-vi-5k1/30971-2-0-gti

Thanks

[Jimbob]

Or could it just be one of these?
https://www.autodoc.co.uk/bosch/7290620?utm_medium=cpc&utm_source=google&tb_prm=20315908947&gshp=1&gad_source=1&gclid=CjwKCAjwpbi4BhByEiwAMC8JnUIHhCAULVt4QkiduKZsfttxkfmAm_zJ4YUBqpOJQmgacWZXdmFv6RoCdPIQAvD_BwE

[Marks DTM Calib]

Live data needed I would say, what is the rail pressure saying it is?

Is there fuel to HPFP feed? (might need to crack a pipe to see)

Pop the plugs out and crank it, see if there is a cylinder getting flooded with fuel as it could be a failed injector stuck open

[Jimbob]

Not sure on reliability  of my data poss 96.92 bar fuel pressure, not even sure if thats plausible.

Will see what else I can check later

[Marks DTM Calib]

About right, it should get to 200bar on full chat. Is there fuel getting to the HPFP feed ok?

The. HPFP is likely just a mechanical part driven off a cam lobe, so pretty bulletproof. The LPFP would be the more likely issue

[Jimbob]

Just had another look, no sign of fuel with no plugs in.  say between 60 and 120 bar cranking
HPFP has voltage at the terminal connection was seeing about 6-8v, but was a bit heath robinson to measure.

After clear and some playing, have intermittant P2296 and P2294 codes.

Theres a hard pipe and a soft pipe to this pump, dunno what to disconnect to check, or any other way of checking where fuel is.

LPFP under the bench in the rear so bit of fun to get to that.

[Marks DTM Calib]

Soft pipe will be the HPFP feed, hard pipe the output to the rail.

The voltage you see will be a PWM signal to control the HPFP output pressure, so 8V ish is probably not far wrong.

LPFP on most modern cars runs for a short spell after unlocking or opening the drivers door, so you should see a bit of fuel delivery to the HPFP feed at that point.

Might be worth having a good look at the wiring harness also given the codes being reported

[Jimbob]

Finally got a break in the downpours to take that pipe off,
Yes, runs with opening the door, and when cranking, pours out at a good rate into a jar, so weve deffo got low pressure fuel.

Nothing obvious to see on the visible wires, be far more hidden though.

[Doctor Gollum]

A weak pump will still deliver fuel, but it may not be enough to fully prime the high pressure one.

[Jimbob]

If that was the case...Surely it would run badly....rather than not even trying to start

the term High pressure worries me a little...is it ok to crack the other pipe and see if that is outputting fuel?

[Doctor Gollum]

If that was the case...Surely it would run badly....rather than not even trying to start

the term High pressure worries me a little...is it ok to crack the other pipe and see if that is outputting fuel?

There might be electronic input from a sensor that disables the hpfp if the low pressure supply is outside a set range in order to protect the hpfp.

[TheBoy]

Is the HP pump direct driven, or belt/chain? If latter, that's obviously something to check.

Sorry, I know less than nothing about that engine.

[Jimbob]

I cant measure pressure...but what came out that hose must be more than it needs by a long shot else that fuel tank would empty very fast 

HPFP is drive by Cam, and there is a plunger between the 2 Ive seen for sale too.  end of this listing theres a few https://www.autodoc.co.uk/car-parts/fuel-injection-pump-high-pressure-pump-12903/vw/golf/golf-vi-5k1/30971-2-0-gti?page=3

Think ill remove the High pressure output and see what I get there, and then perhaps take the pump off and check that plunger and see what weve got.

Gotta get it running again soon, frustratingly little to go on.

[Jimbob]

Not a great update....

Swapped the HPFP with no change at all.
So decided time to get someone in.  Cant get it anywhere, So home start with the AA it was.

Told him the history, he had a prod and a poke, pointed out turning over far too fast, also tried taking the plugs out, number 1 now stuck fast despite it coming out easily when I did it, Do not beleive cross threaded.  Fairly sure the chain has let go. 

It left on the back of his truck to a garage that does engine repairs.  Not gonna be cheap.

[Raeturbo]

 Hope not but, sounds like a valve has bent and hit the spark plug due the the chain slipping?