Running extremely rich

[maggotcorps]

Recently i have noticed a really strong smell of petrol and the fumes coming from my exhaust smell very strongly of petrol as well. What would cause the 944t to run rich?? ECU error? injection system?

 

[NeilW]

Not sure about turbo-specific problems (though I'm sure someone while chime in) but the fuel pressure regulator (FPR) could cause this. The diaphragm within can fail and cause full fuel pressure all the time. You can check this by removing the small bore vacuum line and smelling the end. Presence of petrol and/or smell would suggest a failure. How is the car running?

 

[TTM]

The smell of petrol can be caused by a lack of isolation of the cover above the probe of the fuel tank.

 

[sawood12]

Check for splits and leaks in the intake hoses upstream of the Air Flow Meter. To help you you can use WD40 or carb cleaner - spray around hose joints and areas of hoses that are difficult to inspect visually while the engine is ticking over and listen for a rise in the engine revs.

I can't remember if leaks in the hoses upstream of the AFM causes lean running or rich running. My common sense tells me it would run lean as you are sucking in unmetered air, but I remember when my old Cavalier SRI had a split hose upstream of the AFM and it was running very rich. It's worth checking our for the sake of 30 mins or so with a can of WD40.

 

[Indi9xx]

check fuel pressure, it should be 2.5 bar at idle with the vacuum hoses removed from the damper and regulator.

check that the vacuum hoses when disconnected, do not have a smell of fuel about them.

check that your airflow meter barn door is closing.. it could be that something is obstructing it.

I have seen a couple of 944 turbo DME (ECU) units, which have failed in such a way as they randomly fire the injectors between legitimate injector pulses causing a seriously rich condition... in one case the DME was even keeping the injectors energized even when the engine wasnt running but the ignition switched on.