SoloII///M

iTrader: (13)

Guys, quick question. My recently-rebuilt S5 NA won't idle. It runs like a dream above 3,000 RPM - I spent some time driving it around the parking lot at the shop where my exhaust was done, and it runs great. But under 3,000 RPM I have to keep blipping the gas or it won't run. I haven't been able to get a base timing set onto it because of the idle issue, but based on the fact that it revs like a dream, I feel like it's unlikely to be a timing issue. I'm fairly confident that it doesn't have a vacuum leak major enough to cause this problem as well.

The AFM did get .. um .. dropped during the engine rebuild process, so it's possible that it got hosed. I'm going to pick up a cheap replacement locally but am looking for some confirmation that this could be the problem.

TIA.

JV

calpatriot

Sure sounds like a vacuum leak, but then again...

You can check the voltage coming from the AFM (or any other sensor) by backprobing the appropriate pin on the ECU connector.

Is the ECU seeing a lean mixture at/near idle?

Any trouble codes?

1SWEET7

iTrader: (1)

Is the BAC working right? Is there an idle setup on the Rtek for S5 N/A's like there is for S4 Turbo? Is the idle set screw adjusted properly?

SoloII///M

iTrader: (13)

calpatriot was right - I managed to trap a vacuum hose between the throttle body inlet and the throttle body.

All is good, nothing to see, move along...