urquattro with AAN running lean

[S2central.net]

This one - http://www.s2forum.com/forum/showthread.php?t=52979

[DJones]

Good advice there - only adjustment I would suggest to simplify things is to use the existing fuel pump feed wire to activate the local relay that is fed from the battery. This avoids the need to find the control wire from ECU into the factory fuel pump relay.

Yep that's exactly what i did, snipped the feed wire from the original relay and used it as the (earth) signal wire to a locally mounted relay which feed the pump directly...

[x6rs]

Ideally you want 0V drop between battery and fuel pump... Go with 2.0 or 2.5sqmm wire if you can - its normally a green/yellow wire on the H plug in the UR fusebox that you are interested in - if in doubt, buzz it out.

I would seriously air test *every* aspect of boost control on that machine before presenting the WG chamber with vacuum !!!!!!!!!

Have you checked that diaphragm is OK and bypass valve too ?

I just read your first post again - are you sure the chips are correct for that turbo and injectors cos if they are expecting bigger injectors for high boost running at 5000rpm then the RS2 injectors could be simply maxxing out and unable to provide the desired AFR... weird though that its intermittent. Impossible for me to 2nd guess anything - I only know what my stuff does, also with some enhancements to OBD code so I can log WTF is happening on things like that.

If I was you - would not drive that thing hard until problems are cured !

The H plug? sorry im swedish dont really understand what you mean?

the chipset is made for rs2 injectors.
the diafragm is ok, the wastegate has onlyh seen 15 000km´s since new.
same with bypass valve, and its not an OEM bypass, i think its from forge motorsport, not a cheap china-made one.

yea its really strange, first time it happened it was because i had to little fuel in the tank so at wot in 2nd pump sucked air, filled her up and problem solved, then the next day it started again but with half full tank...

i wont try to get the boost up until i can make it run normal of course, but worst case scenario drop the boost to say 1bar and keep an eye on the lambda reading if i go higher than 5k rpms

[x6rs]

im a total noob about electrics so how do i connect it to the batteri in detail? take the feed line to pump and put it were?

[S2central.net]

'H' plug is referenced on page 9 of this - http://www.s2central.net/S2_Schemati...tic_Primer.pdf - same fusebox on UR - its is H87F for the fuel pump wire if you want to access it from there.

Stupid question - have you reset / unplugged the ECU since the fault first occurred ?

[S2central.net]

on the fuel pump relay upgrade question - search the forum for a sticky on that too !

[x6rs]

okok

not a stupid quaetsion, im stupid sometimes(too often) so no questions are stupid

i have a main switch for the battery power but i have not tried driving it since i switched it off, so maybe its ok now

what sensors should i take a look at tomorrow do you think? preparing a check list for tomorrow now, thanks guys

[newsh]

Ur quattro is so easy to do the relay mod, I picked up 2 volts extra at the pump on mine

http://homepage.ntlworld.com/jh.666/pump.html

or this one

http://www.enginebasics.com/Advanced%20Engine%20Tuning/fuel%20pump%20relay.html

[x6rs]

Ur quattro is so easy to do the relay mod, I picked up 2 volts extra at the pump on mine

http://homepage.ntlworld.com/jh.666/pump.html

or this one

http://www.enginebasics.com/Advanced...p%20relay.html

2volts??? man thats alot! thank you so much for the guides

[x6rs]

so now i have tested the relay mod, easy to do but didnt solve the problem, sure it runs a little richer but not enough, still very lean on high rpms.... where i saw 15 i now see ca 14.5 AFR

the pump is quite noisy so i guess i have to buy another one, anyone know a pump that fits bolt on? bosch 044 maybe?

and do i have to remap if i go for a beefier pump?

[S2central.net]

No remap for bigger better pump required. If that is original pimp then it is just maybe tired out. Either flow test it at say 5bar or whack in a new s2/rs2 or 044 pump.

[x6rs]

No remap for bigger better pump required. If that is original pimp then it is just maybe tired out. Either flow test it at say 5bar or whack in a new s2/rs2 or 044 pump.

yea i will use a bosch 044 probably, but i just got to find one tomorrow, going to make some calls and see if its possible, im going to norway for gatebil on thursday so i must find one near my town or else im f'cked.... so maybe some calls and maybe i take the daily for a spin if i find one not too far away... i heard that the 044 is almost bolt on on an urq s2/s4 have their pumps in the tank unlike the urquattro...

[x6rs]

first call i made when i woke up i found a pump! almost couldnt sleep last night because of the pump issue so feels really good

[S2central.net]

Yeah - its an external version of the 044 for UR

[x6rs]

mounted the 044 pump, no difference besides it runs richer on idle, still lean on high rpms.....BUT! then i changed Maf to a new one i had in my garage and then the afr readings were normal on high rpms, so now the problem is solved tank you everyone!