Oil in MAP Hose

[91gmblack]

Hi All,

re: 1991 GM, 5.0, 238,000 mi.

My car was running rough with bad hesitation. No Codes shown
I cleaned out the EGR valve.
Installed a new EVP sensor.
Installed new plug wires (Motorcraft).
Plugs, PCV valve ok.
Ran out gas in tank, filled w/Sunoco 260, just in case it was bad gas.
No vacuum leaks.

Finally gave up and took it to my mechanic.
He replaced the MAP sensor and said the vacuum line to it was filled with oil.

What could this be??

Thanks in advance,
91gmblack

[mrltd]

the car has 238,000 it's worn out and has blowby....