Mech Fuel Pump Failure ?

[streets]

Hi Everyone,

I have a 1966 Olds Toronado with a 425. The carb has been rebuilt twice and still fails to hold fuel for starting after it sits a week.

We but an inline glass filter before the carb this time, and noticed it has no fuel. Priming it with gas down the carb & cranking it many times pulls it up and it runs fine.

Could this be a bad diaphram in the pump? And would you recommend an electric fuel pump?

Your thoughts are appreciated.

[W_Higgins]

Sounds more like it could be a weak check in the pump. Either way, when's the last time it was serviced?

If the pump's your problem, I'd recommend rebuilding it rather than an electric pump. Aftermarket electric pumps aren't necessarily reliable, and rebuilding your mechanical pump is relatively cheap and will restore proper function without having to deal with all the new problems an electric pump can bring.

I have a '67 Toronado, by the way. Haven't had a chance to do much of anything to it, but it's interesting to see another Toro owner out there.

[streets]

Hi Walter,

thanks for the response.

I wish I knew my carborator terminology better. What you said makes sense as well. It would seem to me that the float acts like a check valve and could have been missed on the rebuild.

If there is no way to maintain pressure there, I could see how it could leak out.

The see through filter throws me off though. It looks like it coul be leaking back down towards the pump.

It was new 4 years ago and it may have deteriorated from lack of use.

Thanks for the advice on an electric pump/ I know they can be tricky.

Hang on to that Toro- with Oldsmobile apart of history now, they may be worth more later.

Dave

[caddyshack]

Dave,

I had the same problem with my 62 vette. I had the carb rebuilt twice, the fuel lines replaced, the tank flushed and sealed, and the fuel pump replaced, all due to adding three gallons of ethanol gas. All of the rubber seals and gaskets failed to hold any pressure and it was a very costly mistake on my part. The pump was the hardest to detect, the fuel just leaked through a fairly new reinforced rubber main diaphragm. I would also stay away from the electric pumps. Good luck!

Skip in frigid MN.

[W_Higgins]

Hi Walter,

thanks for the response.

I wish I knew my carborator terminology better. What you said makes sense as well. It would seem to me that the float acts like a check valve and could have been missed on the rebuild.

If there is no way to maintain pressure there, I could see how it could leak out.

The see through filter throws me off though. It looks like it coul be leaking back down towards the pump.

It was new 4 years ago and it may have deteriorated from lack of use.

Thanks for the advice on an electric pump/ I know they can be tricky.

Hang on to that Toro- with Oldsmobile apart of history now, they may be worth more later.

Dave

Hi Dave. In your case I would start with the pump and go from there. All the overly defensive greenie-weenies will jump in and say, "ethanol has been around for years, blah blah blah", but there are still non-ethanol compatible pump and carb kits floating around out there.

Five years ago, when ethanol was just becoming common here, I had a carb rebuilt by a very reputable carb shop. A couple of months later the owner complained about the performance. While test driving I mashed the pedal to the floor and it didn't come back up. After a hairy few seconds and reaching down to pull it back up, I got it back to the shop, pulled it apart, and found the accelerator pump plunger had swollen-up, yanked off, and bound in the pump well. Needless to say, they promptly sent me a free ethanol compatible replacement.

Now I've got a '51 Ford in the shop that I bought a rebuilt pump for a couple of years ago and after a few months it started doing exactly what your car is doing. The rebuilt pump came from Mexico, so they're either using junk or it's old inventory that was on a shelf somewhere.

Contact these people:

Fuel Pump Rebuilding Kits - Then And Now Automotive

Either buy a kit or just let them do the rebuild for you. They're very reasonable. That's a good place to start. If that doesn't do it, at least you narrowed it down and can go on confidently that the pump won't be an issue for a long time once the problem is fixed.

A pin hole or other very small leak on the suction side can cause the problem you're having, but it's rare that it doesn't show liquid fuel on the floor once the car is running. Even if your whole line runs dry, a properly functioning pump will suck fuel up from the tank in pretty short order.

No plans to sell the Toro. It was the last car my grandparents bought new. It's not something I would go out and buy on my own, but I have memories of a couple of trips in it, and such. It's pretty solid and low mileage. Needs a top and paint job again. Interior is pretty decent. It was parked several years ago because occasionally it would shoot a spark out the signal lever hole and I never got motivated to tear into the tilt-and-telescope column. Someday. It's on the list.

Edited January 9, 2011 by W_Higgins (see edit history)

[streets]

Hey Walter & Skip,

your last posts have me recalling a few facts.

The pump/engine/carb were new NOS or rebuilds 4 + years ago in Arizona that uses no more than 10% Ethanol.

We shipped the car to Illinois 11/2009 where I have filled it up since. Pretty sure the percentage is higher.

There is only one section of rubber fuel line about 2" long. I will replace it, check on the website you gave me Walter on an Ethanlol geared rebuild & see what they say. In any case, I never considered Ethanol a factor.

We are supposed to get our first snowfall tonight here in southern Illinois, so I am relearning what frigid is again Skip.

I put a tilt-telescopic in mine last year Walter, so if I can be of any help with parts or labor know-how, please let me know.

Thanks guys !

Dave

[bhclark]

You shouldn't find any more than 10% anywhere, unless you accidentally fill up with E85.

10% is all that is currently approved for use.

[W_Higgins]

Yep, what Brain said. E10 is what you get if you buy ethanol. All the fuss right now is the talk of them coming out with E15. The E10 we have now is plenty enough to do damage on non-ethanol compatible pump and carb innards.

Thanks for the offer of help with the column. I'm probably a good way from digging into that, but will keep that in mind when I do. Do you know of any common failure item in those that causes what mine is doing?

[streets]

E85 is what I might have seen Brian. I am in southern Illinois now and don't recall any fuel pumps that don't mention at least some quantity of Ethanol in them.

This could be a problem. If the fuel pump was damaged by it that means the carb may not be that far behind. If I can find straight fuel from now on, it seems close to impossible to find a new fuel pump and carb for that year that is Ethanol compatable. I will still give that pump rebuilder a call when I have a chance this week and see if they can help. My original thought was I could resolve this at the least expense by getting a new one from NAPA or AutoZone. I learned something here. Ethanol is a factor.

Thanks everyone.

Walter, there are no known defects in the column. It's just probably old and is shorting out the ts switch. I see by your work on the vehicles you have that your not afraid of a small task. Very nice job on the Lincolns.

If and when you dig into it, more than likely the original wiring can be repaired. If you decide you just want to replace it, I know a few good resourses.

[W_Higgins]

Just call that place I mentioned above. The parts stores won't be the cheapest alternative, and they are well aware of the problem, having made new components impervious to ethanol. There's a chance that what a parts store will sell you will be old stock, too. There's not too many Toro fuel pumps jumping off the shelves.

Thanks for the comment on the Lincoln's. Only one has come along any significant way. Two are to the point I just need to get over the hump with paint. The Limo has only been stabilized and is waiting for its moment in the sun. It runs well, but thanks to a giant rat having used it for its home before I bought it, it needs virtually everything.

[Graham Man]

I use pump fuel (ethanol 10%). My float bowl will be empty after a week, it evaporates out of the carb. I just figure the extra few cranks just helps get oil up in the engine. My 1928 Graham Paige is actually better than my 1984 Ford truck.

I agree on the new (ethanol type) fuel pump parts, are a must.

[Owen_Dyneto]

Not saying you may not have other problems, but Graham Man has the right answer for many of us who use our cars with a week or more in between uses - it's simple gasoline evaporation from the carb fuel bowl. Most if not all carbs have an open vent to the atmosphere when the throttle valves are closed, some a simple vent tube and others an actual valve that is closed when the throttles are opened, often called an anti-percolator valve.

[Dynaflash8]

The whole problem with mechanical fuel pumps failing is Ethanol. It is also causing the ruination of carburetors and gas tanks too. And, apparently there is nothing we can do about it.

[Guest billybird]

streets: I use an electric fuel pump mounted on the left frame rail to prime the carb. I then turn off the electric pump and start and run the car off the mechanical pump. This works real good for me as the car is a driver not a point judged car.

[Guest Evaner]

hey! guy's

I have been read all the above posting and i want to share some thing new information with you guy's actually, A fuel pump is required to draw the gas toward the engine and there are 2 types of fuel pumps

1- The mechanical fuel pump, which was used in carburetor cars

2-T he electric fuel pump, which is used in cars with electronic fuel injection.

I hopes you will got it

Edited January 22, 2011 by Evaner (see edit history)

[joe_padavano]

hey! guy's

I have been read all the above posting and i want to share some thing new information with you guy's actually, A fuel pump is required to draw the gas toward the engine and there are 2 types of fuel pumps

1- The mechanical fuel pump, which was used in carburetor cars

2-T he electric fuel pump, which is used in cars with electronic fuel injection.

I hopes you will got it

There have been electric fuel pumps used with carbs long before EFI was invented.

[1936 D2]

...

We shipped the car to Illinois 11/2009 where I have filled it up since. Pretty sure the percentage is higher..... In any case, I never considered Ethanol a factor.

We are supposed to get our first snowfall tonight here in southern Illinois, so I am relearning what frigid is again...

Hi "streets",

Check out this website for info on where to get NON-ethanol gas. I find the listings are pretty accurate. This is like a wiki set-up so people update it regularly. It lists by City, octane, brand, dealer, address, and sometimes lat/lon coords so you can use your GPS to find the place. Pretty cool!

Ethanol-free gas stations in the U.S. and Canada

Good luck!

[sambarn]

This thread screams the only answer I apparently can give for every fuel issue but when in Rome....

Check/replace all incoming fuel lines/clamps. Between fuel evaporation and possible leak in the fuel line I think you will find your repair. If there is a small crack in a fuel line, the elasticity of the rubber can prevent a visible leak until the pump begins to draw, then air will be drawn in to the crack and run poorly as well as not prime the carb. I had this problem , chased it for months and repaired it for seventy five cents worth of Fuel line. Good Luck!!