dildaxa

Hi All,

I need help please, my A4 B5 2,8 has been running sweet with only 73k for a 98 model, but a few months ago after a run on the motorway I parked her up no problem, the next day trying to start her was an epic and when she did go the engine was spluttering and could not hold a decent idle speed. I also noticed the accelerator had a delay when pressed.

At the time I did not have my Vagcom tool, and reading the forums and similar experiences i thought I would look into a few possibilities, so I changed the starter relay, fuel filter and the fuel pump. when I did the diagnostic it showed and intermittent fault on the MAP, so I changed this.

After this she will start on the first attempt and then run smoothish, but as soon as she is switched off then she does not want to know.

I have considered whether it could be the temp sensor as that has been mentioned about causing starting issues.

I did another diagnostic and now it is giving me different readings as below, it is racking my brain now and I cannot drive her as I know she may not start when stopped.

Help as I miss driving her.

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Address 01: Engine Labels: 078-907-551-ACK.lbl
Part No: 4D0 907 551 R
Component: 2.8L V6/5V MOTR AT D02
Coding: 04251
Shop #: WSC 00353
VCID: 3566B9FB0F52D196BE-4A3A

2 Faults Found:
17967 - Throttle Body (J338)
P1559 - 35-10 - Fault in basic settings - Intermittent
17973 - Throttle Actuator (J338)
P1565 - 35-10 - Lower Stop not Reached - Intermittent
Readiness: N/A

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01V-927-156.lbl
Part No: 8D0 927 156 BE
Component: AG5 01V 2.8l5V RdW 7803
Coding: 00000
Shop #: WSC 00000
VCID: 71EE4DEB3BBABDB6A2-4A3A

2 Faults Found:
18265 - Load Signal
P1857 - 35-10 - Error Message from ECU - Intermittent
00526 - Brake Light Switch (F)
27-00 - Implausible Signal

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8D0-959-655-AI7.lbl
Part No: 8D0 959 655 L
Component: Airbag 7 Audi 0503
Coding: 00104
Shop #: WSC 06435
VCID: 3F8ADBD33D6E1BC664-5000

1 Fault Found:
00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8D0-919-xxx-17.lbl
Part No: 8D0 919 930 J
Component: B5-KOMBIINSTR. VDO D03
Coding: 20462
Shop #: WSC 00353
VCID: 3566B9FB0F52D196BE-50E6

Subsystem 1 - Part No: IMMO
Component: IDENTNR: AUZ7Z0W0345814
IMMO-IDENTNR: AUZ7Z0W0345814

1 Fault Found:
00771 - Fuel Level Sensor (G)
30-10 - Open or Short to Plus - Intermittent

-------------------------------------------------------------------------------

John535is

I would start by checking the throttle body alignment.
In vag-com you can trigger this under basic settings. If you take the intake pipe off you should see the throttle body go through a full open close cycles so its resets full open, full close. Should take about 20-30 seconds. If its not doing this, take the cover off the little actuator and check for anything fowling the movement. From memory there is a little clip stop on the potentiometre, yours may have moved.

Looks like your brake light switch has failed too. This one is an easy fix, they are cheap to purchase, the old switch unclips from behind the pedal by twisting 90 degrees. When you buy the new one DO NOT be tempted to play with the trigger. The switch essentially sets itself to the correct length after its installed when you push the brake pedal down. If you push it in too far by playing with it, it will not come back out and you have wasted your money.

dildaxa

Thanks John,


I will look at the throttle body alignment but how could this be put out, could this have happened when replacing and refitting the MAP?


Not sure if the brake switch has gone faulty as I do recall the brake lights working, but again I will check this.


This may be a start but could the throttle body cause this much issues?

Rsniper4

I'd inspect the spark plugs first. A bad plug results in rough idle and sluggish performance and can trip a whole bunch of other sensors down the line.

dildaxa

Hi Rsniper4,

I did pull all the spark plugs, checked them and gave them a clean before and that did not solve the problem.

dildaxa

Thanks guys for your suggestions, I did another diagnostic and then cleared all the faults, found the temperature sensor was the culprit and also some of the low voltage readings were due to the battery not being fully charged. Changed the sensor and she started no problems, ran another diagnostic and no faults. All sorted now and a happy man as she is back on the road.


Cheers :-):-):-)