Dauntless Fuel Pump Note

On my Buick V6 the Fuel Pump failed-- with age.
This was not a shock.

However the pump filled my crank case with gasoline-- about a gallon's worth in to the oil sump. This happened because the rubber diaphram in the pump leaked in such a way letting gasoline flow into the crank case.

The gas went past the rings in to the combustion chamber and flooded the engine even as it ran. So over about one minute of idling it black smoked---then stalled and would not restart.

Even after the I changed the pump the engine would not start until I Changed the oil and pulled the plugs and cleaned them too. All that gasoline really flooded the combustion chambers-- from the crankcase upward-- a strange thing. As soon as I did all three things (pump, oil change, clean the plugs)--- the engine started and ran normally. BTW--This made me happy-- and I am still smiling.

one thing I noted about the replacement fuel pump was that the cam arm was a little different-- designed to work off the side of the cam lobe instead of riding underneath the cam lobe. Humm--...

I thougt this was a note worthy event.

 

Yeah. A few years back I had the smell of gas but couldn't trace it to a leak. I ended up changing the fuel pump and everything was good.

My concern would be that the gas in the crankcase would take out the bearings.

That and it might decide to burn (explode).

If you smell gas change the pump - or at least check it out.

 

Yes much gasoline in the oil will effect the lubrication qualities of the oil-- and wreak the bearings and cylinder walls-- and on and on-- Also it would be a fire hazzard.


My engine only idled a minute or less with the condition of the fuel pump- pumping gasoline in too the crank case. In Feburary I will finally get my CJ6 licensed and try it on the street.

I just run the engine once and a while in the driveway to keep it from seizing-up. I rebuilt the engine seven years ago-- and it has only run a couple of hours total. It has taken me about 5 years to do the frame-up rebuild of the CJ6-- to the point where is will actually drive.

 

I had the same problem this past summer. I noticed the inline filter had hardly any gas in it so I pulled the oil dipstick and it smelled of gas. Went to the local parts store and picked up a new pump and some indian head shlak. 30 min later we were back in business. Changed the oil and filter and keep smelling it as I run it. Still smells like just oil. I'll keep my eye on it though.

 

do you have a good part # for the fuel pump? who stocks it or can get it?

 

I bought mine at Auto Zone last year. They had to order it. Their part number is 776237. It is a Delco (AC) with 3 ports; it has a third skinny port for the return line.

 

I am building up a 225 for my M38. I just got the pump and it has a 3rd port with a very small hole. You mentioned a return line, does that go back into the tank?

 

Yep.
I think you can plug it.
but not positive.

 

iI can be plugged. I did it on mine.

 

I had mine pluged, but on a high altitude trail (Dusty/Ersim) fuel was backing up due to low crawling speeds and it was hot out . it would flat out vapor lock,had enough hose on the trail and it cured the problem . aways ran fine pluged just the alt.got to it.I'd run it back to the tank.

 

Just an aside: I've got a dual tank setup where it would've been difficult to run a return line because I would've had to come up with some kind of spendy flapper valve and possibly dual pump setup to return fuel to the proper tank in order to preven spillage. I've ran a plugged off return for a couple years without much problem, but every once in a while I would also note peculiar fuel behavior at extended idle periods. Anyway, for an unrelated reason I was shopping for a new pump today and came across an '81 Buick Regal 3.8L pump that appears externally identical to the pump I was running, except it only has 2 ports. Might give it a try.

 

a 1968-1970 Buick 350 pump should be the same, from the same era.

 

I converted to a Carter 4070 Electric pump and removed the machanical pump.

Even a new machanical pump started to go bad in one month. This is because the ethanol softens to rubber pump diaphram and the pressure drops to about 1 pound pressure.

This version Electric pump does 4 pounds pressure-- and works good.- has a metal rotor not a rubber diaphram.

I got my Electric from Summit racing- 70 dollars.

 

I understand that the return line was installed to help prevent vapor lock. I also have dual fuel tanks and have to run the original under seat tank first then switch to the rear tank. When using the rear tank the retun line is refilling the front under seat tank. I think the return line is a good thing. Haven't thought much about what ethanol would do to the rubber in the pump. Maybe I should carry an extra pump. Now I will be a little nervous out on the trail without a spare.

 

Do you have a part number?

 

Thanks, just realized I'm having the same or similar issue of fuel in my oil.