Symptoms of Mechanical Fuel Pump Failure
 

Working w/ an '84 Pontiac Firebird 2.8L V6 (w/ carb). Found fuel
leaking out the bottom of the fuel pump. Pulled it and replaced it. I
noticed a small hole on the back side of diaphragm. I think this was
where the fuel was leaking from. So it doesn't appear to have been
getting into the engine like I remember fuel pumps doing back in the
day.

Q: Is this designed to vent fuel rather than letting it go into the
engine like they used to (in the event of failure)?

Q: How do you tell if gas got in the oil? I don't see any different
coloration and I don't 'smell' it (but changed the oil anyway)

Q: Can gas in the oil do serious engine damage? Or will it just
evaporate?

thanks

Symptoms of Mechanical Fuel Pump Failure
 

On Sun, 28 Nov 2010 10:42:35 -0800 (PST), loadhawg
> wrote:

>Working w/ an '84 Pontiac Firebird 2.8L V6 (w/ carb). Found fuel
>leaking out the bottom of the fuel pump. Pulled it and replaced it. I
>noticed a small hole on the back side of diaphragm. I think this was
>where the fuel was leaking from. So it doesn't appear to have been
>getting into the engine like I remember fuel pumps doing back in the
>day.
>
>Q: Is this designed to vent fuel rather than letting it go into the
>engine like they used to (in the event of failure)?
>

I can't tell you specifically but I would think it depends on just
which part starts leaking as to whether it goes into the engine or out
that little drain.

>Q: How do you tell if gas got in the oil? I don't see any different
>coloration and I don't 'smell' it (but changed the oil anyway)
>

One way would be if the oil level INcreases. Another way would be by
smelling it.

>Q: Can gas in the oil do serious engine damage? Or will it just
>evaporate?
>

If it's not too much it will just evaporate. If it's a lot it will
thin the oil which could be a problem if it thins it too much. I
don't think you have to worry about that happening from what you have
described.

Symptoms of Mechanical Fuel Pump Failure
 

On Nov 28, 1:42*pm, loadhawg > wrote:
> Working w/ an '84 Pontiac Firebird 2.8L V6 (w/ carb). Found fuel
> leaking out the bottom of the fuel pump. Pulled it and replaced it. I
> noticed a small hole on the back side of diaphragm. I think this was
> where the fuel was leaking from. So it doesn't appear to have been
> getting into the engine like I remember fuel pumps doing back in the
> day.
>
> Q: Is this designed to vent fuel rather than letting it go into the
> engine like they used to (in the event of failure)?

The back side of the diaphragm needs to be vented to the atmosphere so
the diaphragm can actually work. Theoretically there should be a seal
in the fuel pump (I've rebuilt a few, the old Carters that were
intended to be rebuilt rather than replaced as a unit when something
fails) that should separate the back side of the diaphragm from the
crankcase, but IME those really only keep oil from entering the fuel
pump, and sometimes not even that - I typically put a little Permatex
on that seal to keep from getting oil blown out the vent hole (BTDT,
scared the hell out of me when smoke started pouring out from under
the car)

>
> Q: How do you tell if gas got in the oil? I don't see any different
> coloration and I don't 'smell' it (but changed the oil anyway)

then you're probably good.

>
> Q: Can gas in the oil do serious engine damage? Or will it just
> evaporate?

Depends on the amount. If it was not enough to produce a fuelish
smell or noticeably thinner viscosity, likely no damage was done.

nate

Symptoms of Mechanical Fuel Pump Failure
 

About two weeks ago I replaced the old worn out mechanical fuel pump and
fuel filter on my 1983 Dodge van.The engine starts up and runs better
now.
cuhulin