Fuel in oil; fuel pressure regulator?

[fdcg27]

The '99 Legacy has rather suddenly began dumping fuel into the engine oil.
The oil is noticeably thin and smells of gasoline.
I'm thinking that a bad fuel pressure regulator is the most likely cause.
No miss, no codes and pretty normal fuel economy.
Anybody have any other ideas?

 

[simple_gifts]

leaky injector.

 

[michaelluscher]

Is it getting up to normal temperature?

Could be a leaky FPR or injector

 

[Quest]

leaky fuel injector, and/or issues with engine running cold (open loop) which will raise the fuel-to-air ratio to "richen" the mixture.

over time, the "richening" of mixture will get down to the crankcase oil.

Check all these areas first.

Q.

 

[fdcg27]

The engine reaches normal operating temperature per the coolant temp gauge.
This is not something which happened over time, but rather something which started about three hundred miles ago.
Prior to that, there was no evidence of fuel in the oil.
Also, my experience with stuck open thermostats is that the loss in fuel economy is unmistakable, but I don't see any loss in fuel economy in this car.
How would I go about checking for a leaking injector?
I'd hate to replace the FPR and then figure out that it was an injector all along.
Just looking for some helpful advice.
If the FPR were a cheaper part, I'd just replace it and hope for the best.

 

[michaelluscher]

You can pull the vacuum hose to the FPR, and wait to see if it's leaking

 

[Falken]

You need a fuel pressure gauge, then read up on how to tap into the fuel rail and do your tests.

IIRC, you do a key on to see if the max pressure is in spec, how long it holds fuel pressure etc.

Just doing a quick look this looks like a good website to get the idea:

http://performancefuelsystems.com/tech-leakdowntest.html

 

[andyd]

Originally Posted By: michaelluscher
You can pull the vacuum hose to the FPR, and wait to see if it's leaking
This is the first thing I would check. Usually it is quick and easy. If gas drips out or it doesnt hold suction. Then the FPR has a hole in its diaphragm.