m20 , smells like it may be running rich

[dimebag_from_hell]

My father has just bought a 325i, car is in fantastic condition throughout, drives like a new car but it really does stink of fuel when at idle. The car seems to be as sore on fuel as any m20 is, not sure yet if it running at poor mpg.

I have check the usual places for possible fuel leaks, all negative.

So where do I go from here, sensors etc?

cheers

[steve_k]

Air leaks, blue temp sensor??

[dimebag_from_hell]

No air leaks, car seems to be going for to well to have an air leek.

[steve_k]

No air leaks, car seems to be going for to well to have an air leek.

Has someone been messing with the adjustment screw on the AFM??

Other than that I'm stumped.

[Rtaylor2208]

I spent months chasing down the same issue, fuel consumption was as expected and perfromance was fine, I replaced all the rubber fuel lines under the bonet, the metal lines had been replaced previously and were in as new condition, replaced the orings on the fuel pump, no signs of a leak and none of this fixed it.

I then systematically checked through all the vacumn pipes for leaks, tested the air meter, TPS, blue temp sensor at the ECU and the sensor itself nothing found there. Injectors were sent off to injector tune for a clean and were refitted with new orings as was the FPR, still the same.

In the end replaced the inlet manifold gaskets, oil filler cap, rocker cover gasket, cam D shape rubber bungs, the breather pipe orings from the inlet to the block and this finally sorted the issue.

My suspicion is that it was the breather pipe as this is known to be a weak point for air leaks and its not easy to test with the usual can of carb cleaner test as around the entrance to the block its usually gummed up with swarf.

[Rtaylor2208]

Also the rubber bung on on the bottom of the TB and the breather pipe that runs along the top of the rocker cover are prime suspects for an air leak.

[Grrrmachine]

Where does the smell of fuel come from - engine bay or rear or car?

If the former, consider pulling the injectors as it may be a split rubber seal. It's worth sending them off to Injectortune to have them rebuilt anyway.

If the latter, it may be any of the fuel hoses or the seal around the tank, but also the rubber O-ring that seals the pump in place. Mine went there and it really stank of fuel in the rear wheel well.

[HairyScreech]

Beware the inlet manifold gaskets, it is easy to say no air leaks but the after market gaskets seem to be plasticy and go hard and crack causing nearly unfindable air leaks.

Ask me how I know.

[dimebag_from_hell]

Where does the smell of fuel come from - engine bay or rear or car?

If the former, consider pulling the injectors as it may be a split rubber seal. It's worth sending them off to Injectortune to have them rebuilt anyway.

If the latter, it may be any of the fuel hoses or the seal around the tank, but also the rubber O-ring that seals the pump in place. Mine went there and it really stank of fuel in the rear wheel well.

Its coming from the rear mate but more so from the exhaust fumes, they smell like pure petrol!

[Grrrmachine]

Undo the ECU plug and check the blue temp sensor then:

http://www.e30zone.net/e30zonewiki/inde ... or#Testing

[Brianmoooore]

Pic. of the spark plug tips would be useful. Remember where each one came from.
Petrol smell in the exhaust doesn't always mean the car is running rich. If the mixture in a cylinder is too weak to ignite, the unburnt fuel will be pumped straight into the exhaust system.