FordOwner6 months ago

[Select] [53 - Parking Brake] [Basic Settings - 04] Group 020 [Go!] Activate the Basic Setting. [ON/OFF/Next] The status of the Longitudinal Acceleration Sensor (G251) is now being displayed. [Done, Go Back]

Pete_W5 months ago

In the end you can bowl out a few issues with a volt meter.

FordOwner4 months ago

The first stage of the investigation was to use a diagnostic tool and obtain any ‘DTC’ (Diagnostic Trouble Code) information and relevant data from the ECU. The scan tool showed the following codes stored in the DTC memory:

Bri19874 months ago

The scan tool can now be disconnected and ignition shut off while mechanical repairs are performed

R2_Amazeballs4 months ago

i dont understand how the dtcs logged just because of the changeover from petrol to lpg only affected cylinders in bank 2 and why long term fuel trim is affected

petHead4 months ago

what i did was disconnected the postive terminal from the battery then kinda sparked it of the terminal a couple of times before fitting it .. this worked for me and got the car running

R2_Amazeballs4 months ago

[Select] [53 - Parking Brake] [Basic Settings - 04] Group 005 [Go!] Activate the Basic Setting. [ON/OFF/Next] The brake pads are now opening. [Done, Go Back] [Close Controller, Go Back - 06]

Pete_W4 months ago

VW Audi Forum do not vet and are not responsible for any information which is posted in this forum. All content is viewed and used by you at your own risk and we do not warrant the accuracy or reliability of any of the information.

Mary4 months ago

search forum is your friend;fuel pump repairs here, http://www.tyresmoke.net/forum/audi-a8-s8/120276-fuel-pump.html

Gary19964 months ago

Nice piece of detective work, it raises a couple of questions for me though.

R2_Amazeballs4 months ago

I agree with Phil, you can assume nothing in diagnosis. I, too am curious in the 4 volts on the open injector ground circuit. Maybe a diagnostic bias? No note was made as to confirming power to the injector? And lastly, just to avoid confusion, (figure 4) isn’t cyl #1 on the front right, not the front left as stated?

Watergirl4 months ago

1) Was the PCM in catalytic convertor protection mode by disabling the #4 injector driver as seen in scope 2 view? It almost has to have been since your 4 volts wasn’t being pulled low. The first thing I would have done is go to the B+ side of the injector to make sure the supply is there. If it was still low (4V), then I’d work upstream from that test point.

Mary4 months ago

there is only one pump in the tank and it feeds petrol to a set of eductors that suck up the petrol in either side of the tank and send it to the fuel rail.

Corrie19994 months ago

Fantastic products and support with unbelievable performance for the money.

Matchmaker14 months ago

One more check was carried out, which was to switch to the LPG system from the standard fuel system. As the LPG requires the ignition system, if all 8 cylinders fired correctly it would have proved that issue lay with the fuel injector.

Porker4 months ago

Firstly take the volts at the battery across the terminals - should be above 12v if battery is good and fully charged.

Pete_W4 months ago

Just the colors of Waveforms need to be swapped.

FordOwner4 months ago

The codes were cleared from the DTC memory and the vehicle was road tested, with no misfire present. To ensure the misfire had been resolved, the LPG was activated and deactivated while on the road test to ensure that the engine could cycle and run on the alternative fuel. No misfire occurred. After the road test, the scan tool was reconnected to check for pending and stored codes. The following codes were retrieved:

MechExp4 months ago

Question: Is there an alternative fix to replacing tank and pump? Has anyone had similiar problems and can point me in the right direction?

FordOwner4 months ago

With the multi-plug removed (Figure 8), it could be seen that the terminals inside had pushed apart over time, and therefore were acting as a pivot when moving with engine vibration. This would cause an intermittent misfire as described in the original fault codes.

FordOwner4 months ago

You can get by with a 120 Ah alt but it will struggle on a cold morning with all your heated seats, full beam and so on.

Watergirl4 months ago

fitted alternator and car would fire then ccut out right away.. it was the immobiliser not turning off which caused the problem

Gary19964 months ago

The multi-plug was stripped down and the terminal pins were replaced and refitted to the injector. The entire wiring harness protector was built up again and the engine no longer misfired.

Gary19964 months ago

This car needs a lot of amps from time to time.

MechExp4 months ago

We assumed that the first 3 DTCs were due to the engine switching from Petrol to LPG and back. This is because these codes are general misfire and fuelling codes, which aren’t relevant to the fault under investigation. The PicoDiagnostics software backs up our theory.

Col Minessota4 months ago

I have a few questions myself if you don’t mind.

FordOwner4 months ago

The first 3 codes concern general misfire and fuelling. These are probably due to the engine switching from Petrol to LPG and back.

MDG Ltd4 months ago

Audi A8 voltmeter fault

had something like this happen to me when i fitted a new alternator to a 2.8 facelift d2 of my friends.

Porker4 months ago

As soon as I know more I will update.............

Gary19964 months ago

[Select] [53 - Parking Brake] [Basic Settings - 04] Group 007 [Go!] Activate the Basic Setting. [ON/OFF/Next] The brake pads are now opening. [Done, Go Back] [Close Controller, Go Back - 06]

MechExp4 months ago

150-120 = 30 which is 20% less. Whoever told you a 120 gives almost as good as a 150 doesn't know his amps from his ar*se! LOL

Mary4 months ago

The Audi A8 is designed with a sophisticated system that allows one or more cylinders to be deactivated in the event of a continuous misfire.

Porker4 months ago

We knew that we were currently firing on only 7 cylinders and so, before switching to LPG, we must switch off the ignition and restart the engine. Upon restarting the engine and switching to LPG, all 8 cylinders began to fire successfully. This confirmed what we had already suspected: that both mechanical power and spark were present.

Col Minessota4 months ago

The support I have received from Pico over the years has been superb. The regular software and driver updates are a real bonus.

Col Minessota4 months ago

2) Why doesn’t Alldata have any wiring diagrams for injection on your Audi A-8? Is this only in the VAG/VAS scan tool? I have very little experience with German built vehicles, but this seems wierd not having electrical wiring diagrams/schematics in a cataloged service information system.

Bri19874 months ago

i just put some more pics here yesterday, Fuel pump assembly knowledge needed... - Page 2 - AudiWorld Forums

FordOwner4 months ago

- www.vwaudiforum.co.uk - www.vwaudiforum.co.uk -

Corrie19994 months ago

Was there a reason (apart from speed) for using auto ranging on the voltage scale?

MDG Ltd4 months ago

I think you are being fed a load of bull! :mad:

Corrie19994 months ago

It looks like I need to investigate this further as the info on here definateley contradicts what I have been told by the garage? One for the new year.............

Bri19873 months ago
This problem has been solved

- see solution here