Running Rich - High Oil Pressure - Possible plugged fuel return line?

[_kanon]

So in my long quest to conquer problems on my car, I came across this thread: http://www.r3vlimited.com/board/show...=204298&page=1

My car runs fairly rich, I can smell the gas as I go in reverse and when I start up the car. My exhaust has soot? all over the inside. I've bought the car recently and I'm still figuring everything out. Here's what I do know atm about my 2.7i:

- 0 280 150 716 - 88' 325E Injectors - 134 cc/min (VS stock i injectors which are 149cc/min - i could be running lean?)
- 083 AFM
- Grey label 173 DME
- Motor Head label reads 2.7/2.5 - leads me to believe it is indeed a 325i 885 head

My question (following some of the train of thought in that thread): Is it possible for a plugged fuel return line to

- Cause high oil pressure (75-80 PSI at idle & Over 100PSI - the highest reading I have - at normal operating speeds)
- Cause the engine to run rich
- Cause a vacuum at the gas door strong enough to prevent it from opening normally. (i have to bang it a couple times for it to budge and when i open the gas cap, you can hear the vacuum being filled)

Thanks for your help guys, r3v has definitely been extremely helpful and educational :)


Kelly

[TobyB]

No, your fuel return line can't affect oil pressure in the least.

It WILL affect FUEL pressure, if that's what you meant.

Yes, it will cause it to run rich

No, it shouldn't cause a vacuum at the tank.

Easy to test- put a pressure gauge on the fuel rail. If it's high
and routing the return line (safely) to a dump can (like a 5 gal fuel jug)
fixes it, and you can't blow air back into the return, yuppers, it's plugged.
Or crimped shut from too much stance.

hth

t

[_kanon]

No, your fuel return line can't affect oil pressure in the least.

It WILL affect FUEL pressure, if that's what you meant.

Yes, it will cause it to run rich

No, it shouldn't cause a vacuum at the tank.

Easy to test- put a pressure gauge on the fuel rail. If it's high
and routing the return line (safely) to a dump can (like a 5 gal fuel jug)
fixes it, and you can't blow air back into the return, yuppers, it's plugged.
Or crimped shut from too much stance.

hth

t

Toby,

It definitely helps. Yes I meant fuel pressure, thanks for catching that. Looks like I'll be doing some pressure tests this weekend. I'll keep the thread updated with anything I find. Thanks for your help!

[TobyB]

I have to admit, when I first read that, my brain read 'fuel' pressure, too...
...then it got confused. It doesn't take much, these days!

Good luck,
t