One for you old Octy vRS tuners! Audi TT

[devonutopia]

When I say old, I mean the cars not the drivers necessarily.

A BAM powered 225 TT gave the following log. As can be seen, requested boost is at 1.5 bar (car is stage 2 mapped) but the car is failing to produce barely 0.4 bar. These are the two fault codes which come up. Any ideas?

Address 01: Engine Labels: Redir Fail!

Part No: 8N0 906 018 H

Component: 1.8L R4/5VT 0004

Coding: 10710

Shop #: WSC 00000

VCID: 3666AACB38D7

TRUZZZ8NZ11026274 AUZ5Z0YD062009

2 Faults Found:

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

P1128 - 35-00 - -

16395 - Bank 1: Camshaft A (Intake): Retard Setpoint not Reached (Over-Advanced)

P0011 - 35-10 - - - Intermittent

Readiness: 0000 0001

[rk696]

MAF readings look way low to me. Even a stage 1 map on a 180 engine should be registering around 170g/s at full chat. Yours doesn't even get to 100.

Could also have a fueling issue, maybe starvation. Change the fuel filter for what it costs, and check for a boost leak or split dv.

Could also be a failed N75 as it doesn't seem to be making any boost at all.

[devonutopia]

For reference, when I cleared the fault codes and tried again, the MAF gave readings of approx 50% more than the above run. It gave full boost, but not full power - quite a bit of engine shudder/misfire too, but oddly the fault codes stayed away for about 30 miles. I think it "could" be the MAF but I think the low MAF readings are symptomatic of another issue. Liking the N75 thoughts as I know how critical this is to any turbocharged engine. Those fault codes are very odd though - all relating to bank 1.

[devonutopia]

lol, - 99 views and 1 response. Have none of you 1.8T owners had anything similar before?

[The Ors]

lol, - 99 views and 1 response. Have none of you 1.8T owners had anything similar before?

Might get a better response from the Octy 1 forum???

[devonutopia]

I thought that, but as a moderator I know a thread about Audi TT issues will not go down well in the Octy 1 forum Probably get me sacked!

[cheezemonkhai]

I'd do a fuel filter for starters as retarding can be a sign of poor quality fuel.

[rk696]

Well, I reckon try a new N75, MAF and fuel filter. It seems you are making 5 psi across the board, which is quite close to the pressure you would get if the n75 was stuck open (turbo opens its own wastegate). Have you tried measuring the AFR ratios, as it may be fuel starvation causin the ecu to cut boost maybe?

Either that or the turbo is goosed.