17536: Fuel Trim: Bank 1 (Mult): System too Lean

Jonzy

Guest
what happens if you drive with the relevant sensors unplugged - wild guess... id be screaming by now.
 

Feel

Veedubya 'velle
Jun 12, 2003
4,918
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Midlands
:think: Running lean would make it a leak between the MAF and the turbo, wouldn't it? Otherwise it would be a boost leak and it would run rich? But he's swapped the TIP back.

It's not a leak on one of the ancillary pipes off the TIP is it, post DV or something? I think I saw a nice shiney 007p under there the other week?
 
Phil, OEM TIP is back on and everything is as tight as you'd want it to be....including around the 007P. The thick pipe connecting to the DV and 'Cut Off Valve' could do with replacing though as I've never liked the look at them!

Brend, IC pipes are tight as you'd want them to be too....
 

Feel

Veedubya 'velle
Jun 12, 2003
4,918
2
Midlands
Maybe I should say what I said in that deleted post then - shame you can't rig up a device like Steve Schwing sells - to allow you to pressurise your system with a compressor, with the engine off...
 

Glenn

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Oct 15, 2001
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Feel said:
:think: Running lean would make it a leak between the MAF and the turbo, wouldn't it?

It could also be a leak on the exhaust side, pre-lambda probe or as I mentioned to Martyn the other day, the Lambda bung is keeping the probe out of the main flow, like the post-cat spacers - would expect to see idle trim way off as well though?

Lean is too much air or not enough fuel - hose to FPR from manifold ok? One thing I did think was odd was that when we cleared the trims live with engine running, you can hear the dip in RPM as it adjusts but the duration shown in VAG-COM didn't change? If VAG-COM doesn't show the corrected duration, then say if Martyn's 4 bar reg is actually a 3 bar in the wrong box or something (stranger things have happened!) we wouldn't be able to see it? :confused:

Haven't got Excel on this machine but I'll cross check my duration numbers at given mass flow with yours tomorrow to see how they match up.
 
Jonzy, Revo is set to standard at the moment but 'Revo - Standard' is different to 'Standard ECU - Standard'.

Glenn, DP bolts were double checked today when the probe was replaced. 4 bar FPR is definately a 4 bar one, it's engraved on the side :)

Phil, pressure tester would be very handy.
 

Jonzy

Guest
Any damaged/dodgy wiring giving incorrect readings, I had a problem with a MAF sensor on my last car, turned out to be a corroded pin in the plug.
 

vern

I Miss Her Below!
Jun 17, 2003
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Jonzy said:
Any damaged/dodgy wiring giving incorrect readings, I had a problem with a MAF sensor on my last car, turned out to be a corroded pin in the plug.
:wtf: badluck mate, as jonzy says, i think maf related , check plug and all wiring connections to and from, weird one, hope it aint your ecu!!!!i doubt it though
 

Glenn

Full Member
Oct 15, 2001
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While we're clutching at straws, I had another thought last night - secondary air injection, where does the pipe out of the pump feed into the exhaust? I couldn't see on mine this morning but check it's intact - no hairline cracks, etc. Again, I'd expect to see that at idle or incorrect flow codes but it's worth a check before buying more new bits?
 
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