Hey guys.
Having a few dramas with the mechanical fuel pump in my 95 Sierra. I purchased the zook a short time ago and a couple of days later noticed that the fuel pump was leaking oil from the vent pipe at the back of the pump. So, I replaced the pump with a new fuelmiser one, drained and replaced oil and filter then cleaned the areas soaked in oil to aid in detection of more leaking. Thought i was in the clear, but now the leak has started again (about a month after replacement). So, after reading about PCV valve blockages causing a leaking fuel pump, I decided to replace the PCV valve and clean out the T-piece and the three vacuum hoses that connect to it. I also removed the fuel pump and drained the oil that had made its way in. But still, after a day or two, it started leaking oil.
The oil that has been leaking does not smell of fuel, but i am still concerned as almost everything i read relating to a leaky fuel pump mentions that it means the diaphragm has fractured and fuel is contaminating the engine oil. Although i came across Acks FAQ and the page states that oil leaking from the vent pipe usually indicates a blocked PCV valve, whereas a vent pipe leaking fuel means that the diaphragm has fractured. Here's the page:
http://www.acksfaq.com/mechanical_fuel_pump.htmIn either case i've performed both repairs.
So, I'm thinking:
I've installed the fuel pump wrong. I tried turning the engine over by hand, with the leads still on, to try and get the fuel pump rod retracted as far into the block as possible, but it did not move (although i only turned maybe one full rotation and stopped because it didn't move). Then, when cleaning the mating surface i accidently pushed the rod in quite a bit, it slowly moved back out so i pushed it more delicately and it stayed - is this movement by hand normal?
OR
There is still a blockage somewhere causing pressure inside the block, which then causes oil to make its way between the fuel pump rod, into the fuel pump and out the vent pipe.
OR
Damage/faulty/worn fuel pump rod or camshaft fuel pump lobe
OR
(This could be way off) When replacing the oil i have put a little too much in and the excess is coming out of the vent pipe.
Repco are replacing my fuel pump and I will go ahead and change them over. But if history repeats itself and in no time my pump is leaking again, i was wondering if anyone on here might be able to point me in the direction of any other causes? If i cant remedy this problem the next logical path to take seems to be converting to an electrical fuel pump. Can anyone that has done this let me know how difficult it is? Quite a novice around engines but with the right information im pretty confident.
CHEERS AUSZOOKERS! And sorry if it seems like i've waffled on in this post but i just wanted to give all possible background info that might help.
Any information is greatly appreciated.
