The Stovebolt Site Forums The Shop Area Engine Shop ethanol and fuel pump

The fuel pump on my 1946 Art Deco 1/2 ton 216 stock engine is giving me problems again, I just changed it out about 6 months ago, and I thought someone might know if the fuel pumps from places on-line or 'the truck shop' fuel pumps have issues. All gas here in Cali seems to have some ethanol in it now and I came across a on-line rebuild kit for the fuel pump that says it is made to withstand the ethanol in gas. These kits are expensive and I am just putting this out there to see if anyone has info on this topic. It seems that the manufacturer would already account for this, right? Anyone gone this extra step or do you feel I might be over thinking this?

As has been discussed here before, replacement fuel pumps are a hit or miss proposition these days. Last a few months or a few days or if lucky a few years. If you have the skills rebuild it yourself with a good quality kit.

If you are intent on using a mechanical pump, your best bet is to find an older made in the USA pump and rebuild it with ethanol-resistant internals. A couple of weeks ago I gave one away for cost of shipping here.

The company known as "Then & Now Automotive" produces ethanol friendly rebuilding kits.

I will give them the highest recommendation possible.

New off-shore pumps have another issue which is at least as serious as the ethanol problem, and that is the inconsistency of fuel pressure. Even Carter replacement carburetors do not like 11 psi. Guess how the Rochester B reacts to a pressure like this!

Jon.

Then & Now Automotive A+++++
They rebuilt my AC Fuel /Vaccum pump 2 years ago.
Came back better than new!
Todd

Thanks: Then and Now Automotive

Thanks for the input, I was considering an electric pump but then realized I would need to wire it to shut down if something happened under the hood, so for now I will figure out this issue and try another mechanical pump. I will look into 'then & now".
The pressure issue is something I was not even thinking about. I guess 7 or 8 psi should be my max?

It is easy to get another oil pressure gauge and a relay and bypass switch to allow electric fuel pump to shut off when oil pressure is lost.

Ed

Three to four would be better!

Jon.

Mine Rebuilt was 3.5 Lbs Pressure!
They nailed it perfect.
Todd
RE AC Dual Fuel pump.

The spring inside a fuel pump determines what the output pressure will be. If you're rebuilding a pump and the replacement spring in the kit makes the lever arm a LOT harder to move, chances are you're building in a problem instead of helping yourself.
Jerry

The pressure can be as low as 2.5 and you will be just fine.

Most of the ones I've seen are just powered by any power source that comes on when you turn the key on, have issues under the hood, shut the engine off, fuel pump shuts off too.

That's extremely high. My 1966 Toronado with a 400hp engine requires a pump in the range 7 3/4 - 9psi. There's no way you need 7 or 8 psi on a 76 year old inline six.

My 216's pump registers between 2.5 and 3psi.

Rods46,

The max spec was 4.5 psi at the carburetor, according to the old Chevy documentation.

If you would prefer an electric fuel pump, and still running the 6V system, Airtex E8902 or equivalent is a good choice, comes with an inlet fuel filter, and can be plumbed in near the tank. Airtex E8902 6V Fuel Pump. Output pressure max is 4.5 psi.

If the truck is converted to 12V, the similar pump is Airtex E8251 or equivalent Airtex E8251 12V Fuel Pump. Again, max output fuel pressure is 4.5psi. To be exactly similar to the 6V pump, an inlet fuel filter can be added (since the 12V model does not come with the filter). Wix P/N 33046 is essentially identical to the filter supplied with the 6V pump, and directly threads into the pump's inlet fitting. If a 5/16" tubing inverse flare fitting is desired at the filter inlet, Wix P/N 33081 may be used instead.

Wix P/N 33046 fuel filter (same as NAPA P/N 3046) is a correct replacement unit for the inlet filter that comes with the 6V pump, also. Or, Wix P/N 33081 (same as NAPA 3081) can be used if a 5/16" inverse flare is desired on the inlet side.

Now, for the safety cutoff and pump installation, Airtex published this 3-minute video several years ago that explains both. The recommended oil pressure cut-off switch is nothing more than a GM three-terminal switch that was used very commonly in the '70's to early '80s on a number of cars and Chevy trucks. The Airtex P/N OS75 that is mentioned in the video crosses over to Delphi FA0004, NAPA Echlin OP6610 or OP6617, or GM P/N 3986857. Here's the video that shows the wiring and pump installation: Airtex Universal Electric Fuel Pump Installation Video.

There are a couple details in the video that I do not particularly like. The pump installation uses rubber hoses at both sides of the pump. While that will work, an appropriate inverse flare fitting can be used to hardline the outlet side. In that case, I use a simple vibration isolator under the pump. The video also shows Teflon tape used to seal the pipe threads into the pump and for the oil pressure switch and fittings. Teflon tape shedding is an issue if it gets in the fuel system. I prefer to use an ethanol gasoline and oil-compatible sealant like Permatex 56521 (Loctite 565) instead of the tape.

Hope this all helps!

Doug