Fuel pressure problems

[Uncleben]

Yeah, I'll see if i can get hold of a pressure tester just to confirm the readings.
I've been reading through a lot of vw literature about the fsi fuel system and it states that if the fuel pump control module is replaced it needs to be adapted using vag com, so although I tried a different control module and it made no difference, could it be that it needed to be adapted? or is that referring to if a brand new one is fitted, I tried a used one off a similar car?
VW do state though that if the control module fails then the engine will not run so maybe I'm down another dead end.

[FJB]

When my fuel control module failed (the one under the back seat) the car would not run. I purchased a later revision module on eBay from a Scirocco, I don't remember the part number, but the 1st 3 digits were different, number the same with a different letter at the end. Worked fine straight away when installed, no coding required.

[pudding]

That certainly is a possibility but not something I've meddled with personally.  As with many of these things that need 'adapting', simply removing the battery for an hour or longer (to drain away capacitive charge) forces the modules/parts to re-adapt themselves.  So you could try that?

EDIT: Just seen FJB's reply, so there's another answer 

[ttelracs]

When my fuel control module failed (the one under the back seat) the car would not run. I purchased a later revision module on eBay from a Scirocco, I don't remember the part number, but the 1st 3 digits were different, number the same with a different letter at the end. Worked fine straight away when installed, no coding required.

I've done this on my previous Mk5 GTI and current Audi 2.0 TFSI.

[Uncleben]

I suspected that might be the case.
My battery is disconnected at the moment anyway as the car is just sat there, but good to know for future shenanigans!
Has anyone tried an aftermarket HPFP? There are a couple for around the £130-£150 mark, I might try one just to see as I don't think I can bring myself to give in just yet.
Thanks for all the replies 

[pudding]

I tried a Loba one years ago but they chew through cam followers.  The VIS motorsport internals are a safer bet as it retains the factory piston spring, therefore no additional load on the follower.

[Uncleben]

Would it be worth checking what the injectors are doing? I spoke to a mechanic who suggested reading the injector values, or if possible, removing the fuel rail with the injectors (leaving everything connected) turn it around and see if the injectors all squirt equally when turning engine over. I would have thought any injector problems would throw a fault code? I suppose it wouldnt hurt to read the injector data, are you able to compare specified vs actual on the injectors, or is it pointless?

[pudding]

Injectors aren't monitored in terms of ECU control, only whether they are physically connected or not.  The ECU instead relies on MAF readings and 02 sensors to monitor the burn, but even then, only 1 sensor is shared across 4 cylinders, so it's all a bit crap really.

Anyway...... removing the intake to watch the injectors during cranking isn't practical due to the hard lines.  They won't be the cause of your fuel supply problems anyway.  If the engine starts and runs, it's not them.

[Uncleben]

Well thats good news, at least they can be ruled out.
I've decided to try a new HPFP, If I got rid of the car without trying one I'd always wonder if that was the cause, or regret not spending £150 to possibly fix the issue!

[pudding]

I agree. It seems like you've exhausted all other avenues, so why not!

[Uncleben]

Well, I fitted the new HPFP today.................and it seems to have fixed the issue! couldn't drive it too much as the mot has ran out but gave it a couple of full throttle runs in 2nd and 3rd and it pulled strong and clean, so looking promising.
Wasn't looking forward to doing it as i'd read so much about the banjo bolt, but with a flexi head 10mm ratchet spanner and long m8 triple square bit it was a doddle, had the old one off and new one on in 30 mins, only trouble i had was where the schraeder valve should be, someone had replaced it with a cut down 13mm bolt, completely different thread, so didnt fancy forcing that into my new pump! luckily still had the old low fuel pressure sensor, so screwed that in temporarily until i get the correct part.
The cam follower looked fine so re used that.
Many thanks for all your help, especially @Pudding 

[pudding]

Happy days