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Fuel in Oil / 1.8k


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Just checked the oil and I detect a distinct petrol odour. 
Its a 1.8k. I recently cleaned and reoiled the ITG foam filter on Jenvey TB's using the thicker JD2 oil.

Do you think the thicker oil might be restricting the air flow and the engine is over fuelling? 

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A thicker oil treatment on the air filter may reduce air flow which may confuse the inlet sensor causing possible over fueling at certain throttle positions. 

If the engine is being 'over fueled' then you would probably have other symptoms - possibly rough running/idle & not being able to sustain idle. Black plugs are a good indication.

Of course there may be washing past the pistons & if this is the case then there may be more to the problem than just over fueling. 

Also as the oil is now fuel contaminated best to change it before it gets further diluted. 

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As you are running direct to head throttle bodies there are no sensors to confuse, you may have an inlet temperature sensor but you do not have an air flow meter of any kind, the map will be based on throttle position and rpm, with maybe some temp correction. The oil on the filter will have no impact on the airflow as the filter has a many times greater area than the inlet ports, and the change in oil viscosity will be minimum

So  if the engine is generally running well I would be looking to see if any of your injectors are leaking/ not closing properly. When your fuel pump primes, before you start the engine, or after you shut down but leave the ignition on, you have 3.5ish bar of fuel pressure behind the injectors a small leak will put fuel into the cylinders and it will leak into the sump. is the sump oil level increasing?

you can pull the fuel rail with the 4 injectors out and leave it connected to the fuel lines, then prime the fuel pump and look for leaks. or you may well be able to just look into your throttle bodies with the throttles open and see if there is fuel weeping into any cylinders (depends where your injectors are located)




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