Audi A8 (1994 - 2003) - 97 4.2 S8 refuses to start

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Sat 7 Nov 2009 12:02
97 4.2 S8 refuses to start - Daedalus
My S8 refuses to start!

It cranks over OK but not even a hint of wanting to start. On my way home last night it ran beautifully, smooth, silent, fast, as best as it ever has which usually means there is an imminent issue with it. Come out this morning and nothing. It has an LPG conversion on it so it stopped on LPG last night. I have tried to VAGCom it but I cannot establish communication with the ECU (not good). I thought it may be the fuel relay but that it is not where it is supposed to be according to the manual which is in the fuse compartment in the RH footwell, there are no relays at all in that compartment. It is listed as R17 but I cannot find that in the LH footwell relay panel either.

Do any of you fine gentlemen and ladies have any idea on what could be wrong? Someone usually has a good pointer.

Thanks

Daedalus
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Sat 7 Nov 2009 13:05
97 4.2 S8 refuses to start - elekie&a/c doctor
No comms with the ecu could indicate a power failure to it.Bosch info shows the main efi relay and fuses to be under plastic cover in plenum chamber ,rear of engine bay .There are also fuses in drivers footwell and relays in pass footwell relay plate.Howevever,there are probably variants of this layout.hth
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Sat 7 Nov 2009 16:01
97 4.2 S8 refuses to start - Peter D
Yep the Motronic Engine Management Unit is in the plenum chamber electronics box. Regards Peter
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Sat 7 Nov 2009 16:09
97 4.2 S8 refuses to start - Peter D
Post this on www.vwaudiforum.co.uk

It the correct section and in the A6 section.

Regards

Peter
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