Running to lean

[rench]

Cars having some running problems, over last few days it's either all power there or not boosting up right, dv still comes in. Checked for boost leaks carnt find anything. Also engine light came on scanned it came up with system to lean? Any ideas?

[richw911]

Whats the code?

[rench]

17536 system to lean, when I reset code engine light went and it's seems to drive fine again for now second time I've reset it in 2days.

[topher]

that one means its going lean under load.. which is always worrying. Basically your lambda sensors are telling the ECU you're not getting enough fuel. The ECU will try to compensate for it but will only go so far before putting you in limp mode to save the engine. Could be that the lambda sensor itself is giving false readings, but 9 times out of 10 this fault is down to a dodgy MAF sensor. You also have to consider that it could be a problem with the fuel delivery (weak pump, bad injector, blocked filter/lines etc..)

[rench]

Any way to test any of these? Wares best place to start?

[topher]

live data logging with vcds or similar. If you just have one of those hand held scanners you'll have to find someone nearby with the right kit.

[rench]

Will a good vag com not say what's causing the problem I only have a cheap eBay one.

[topher]

vcds = vag com diagnostic system im pretty sure the freeware version wont do data logging though

[rench]

awww right, my mates got a good vag com hand held joby cost about £200 will that do the job or does it need one thats connected to laptop?

[Wazzzer]

laptop really to do proper logs