Tfsi fueling issue please help guys

[08_edi30]

Hi guys I hope this ok my car is actually an Audi s3 8p running a bhz engine.

I know this forum is for vw golf’s I did own an edition30 before this pain in the arse !!
I’ve asked on various Audi pages on Facebook without any help and this forum always helped out with probs on my edition30 anyway so my s3 randomly had a hiccup whilst accelerating hard out of the blue it felt like i hit a hard fuel cut at 5k rpm in 3 rs gear.

Drive home fine thought it was driver error.

Went to work the next day and it stuttered whilst just cruising. Again ignored it.

So went out one evening for drive it was fine, stoped and then went to pull away from a junction and it cut out just as I was about to pull out of the junction.

It would start easily and when it did start it wouldn’t idle and cut out again even with me trying to rev it.

Finally got it started after a fashion with nearly foot all the way down on the throttle whilst turning it over.

Managed to keep it running and get home which was about 10 miles on a dual carriageway.

It wasn’t happy at all and was randomly stuttering.

Once home I hooked vcds up at I had no eml.

It said I had fault code p119a fuel pressure sensor intermittent.

Cleared the code and it didn’t come back on.

Left the car a week and went out again thinking I’d see what happens.

It was going ok but then I pulled away from a set of lights hard and I lost all throttle response and the car just died and refused to start.

I was just turning over a bit like I’d run out of fuel.
After about 5 or so mins I got it started and drove home.

Fault codes this time

P0190 fuel pressure sensor -intermittent
P2414 oxygen sensor b1 s1 voltage too low/ air leak/sample error
P0088 fuel rail system pressure too high intermittent
But no eml on dash


So again cleared the codes, replaced fuel pressure sensor,spark plugs, replaced fuel line from hpfp to fuel rail.

I’ve been out in the car since and I’ve driven it hard and it hasn’t cut out or died on me but it has stuttered a couple of time very faintly though.

It’s also stuttered weirdly when turning sharp left or sharp right ????

I’ve got nearly half a tank of fuel currently.

I have logged the car as per advice from tfsi tuning on Facebook but I don’t know how  :happy2:to read them and not sure if they look how they shouldn?

My cars currently running stage 2with intercooler, 3” decat, revo intake, rev g,.

Not really sure where to look next.

Sorry for the long post guys I’d be grateful to hear from you guys in the know

This is the link to my log that I done

https://log.tunezilla.com/s/mqv7lgtb

[skkane]

Check the sensor on top of the HPFP for cracks (the one that you can't replace on its own) and also check the wiring to it. Check the wiring to all 4 coils and try to borrow coils from a friend and have a go. I had a bad coil once (the electrical plug connection thing in 1 coil was cracked so when giving it some the plug would move in the coil causing disconnects) and got random fuel cuts above 4000 rpm, putting me in limp mode. The errors I had were all fuel related so I changed two LPFP's and a HPFP for nothing...

You could also log the fuel system and see if the requested value meets the actual. VCDS measuring blocks 230 / 231 for the HPFP / LPFP. But these can throw you off since a bad coil would cause pressure drops in the system and get your replacing what you don't need. I'd test with new / known working coils first since it's easiest.

I didn't have any lambda related errors though so a bad lambda probe / sensor or wiring might also cause it I guess. Harder to check that one without getting under the car or running lambda related logs with someone who can actually read and interpret them :)

[08_edi30]

Hi, if you click the link that is the log I done a couple of evenings ago.

I used measuring blocks 230 & 231

[skkane]

Those logs look alright. Guessing there were no cutouts when u did them.

[08_edi30]

None buddy, it’s stage 2 and only producing 301 bhp dyno printout says 337 bhp.
It’s weird perhaps I’ll take it out for a few more blasts and log it some more but difficult when the problem doesn’t happen when logging it !!

I was tempted to pull the injectors and send them off to be checked and have the stainless baskets fitted if they are all good.

The hpfp solenoid isn’t  cracked either the whole thing was replaced brand new 2/3 years back got the receipt for it.

Cam follower I’ve changed
Cam looks ok too

Not sure if the tank pump is ok mind you

[pudding]

Hard cuts are usually the result of too much boost or not enough fuel, or both.

Weird that the requested HPFP pressure is only 109.9 bar. That is stock pressure for an ED30 running 0.9 bar boost. I'm not sure what the stock rail pressure on the S3 is as they run 1.2 bar boost as standard.

Stage 2 should be around 130bar requested when nailing it.  That could be due to the ECU being unhappy and holding it back maybe.

I was getting crazy hard cuts running 1.7 bar. K04s surge badly if you cram in too much boost too soon and the engine can't swallow it, although that normally happens at 3000rpm, not 5K.  A bad crank sensor can cause a hard cut at 5K, but it normally fault codes that.  Can you drive through 5K with gentle throttle? If so, that outrules the crank sensor.

My guess is a fuelling shortfall but ideally it needs diagnosing on a dyno so you can load the engine up and watch what's happening in real time.

Requested and actual boost pressure and throttle position would be useful to log. You can then see what the fuel is doing at peak boost, but it's proper sketchy logging on the road. Too many clowns getting in the way.

[08_edi30]

I did log the car back in the summer which included boost request and actual I’ll get the link and post it up for you to look at.

just been out for a quick blast while the roads are dead and the can feels like it’s being held back, it’s really weird, best way of describing it is it feels like the handbrake is on when accelerating so when foot off the throttle down on the clutch you can feel it being held back.


I’ll get the logs link posted shortly

[08_edi30]

Here’s the link which also includes boost pressure

https://log.tunezilla.com/s/glzhPbKa

[08_edi30]

another log I done back in the summer

https://log.tunezilla.com/s/MdsaixDc

I’ve just compared the logs to my old ed30 and the the s3 is not running as much a boost or fuel pressure as my old ed30.

[pudding]

The requested boost and rail pressures in those logs would suggest a standard S3 map to me.  1.2-1.3 bar is about what a Stage 1 Eddy would run, but with 120bar rail pressure. 109.9 bar requested is usually a sign of a standard map. Yours did go over that slightly in places but that's just error margin due to the time it takes for the pump to react to ECU commands.

The holding back in boost sounds like a lean condition to me. No fuel, no power. It's that simple unfortunately. Although if it really is a standard or very mild map, the stock fuelling can cope with that, or it does if it's all in good condition.