Fuel Pump Talk

[55 Fargo]

Hi is anyone used or ever used a Carter M847 fuel pump from Rock Auto.

If so are these okay with modern fuel blends, and how about quality and longevity.

So far my OEM fuel pump is working well, but want a decent spare for emergency back up, I either g this route or install an electric fuel pump for hot starts and emergency back up.

Here is a link for Rock Autos fuel pump..

http://www.rockauto.com/catalog/moreinfo.php?pk=296246

[James_Douglas]

Several years back I talked with a tech at Federal Mogul (Carter). The topic was 6 Volt fuel pumps. He was very knowledgeable and this is what he said:

• Part Number P4259 works on 6 volt positive or negative ground.
  
• The rebuild kit (no motor) is part number 888-178.
  
• The pump has a maximum pressure of 5.75 PSI.
  
• This unit is a full time on unit and will not allow for a proper flow through if off. (use by itself, not with engine pump)
  
• This unit must be installed at a level equal to the bottom of the fuel tank.
  
• This unit must be within 2 fuel line feet of the tank.
  
• This unit typically drops between 1 to 1.5 PSI at the carburetor inlet. Less loss for shorter fuel line runs (Coupes) and more loss for longer runs (sedans).
  
• The only issue when using these pumps on small HP engines is as follows. These pumps must have 5 gallons of flow every hour to keep within operating temperatures. If you are at idle for over 30 plus minutes on a hot day in traffic and your engine does not pull enough fuel through the pump could overheat. The thing to do according to Carter is to put a fuel line tee up in the engine with a 1/8 or 3/32 orifice and a return line to the gas tank. That way the pump will always have enough fuel running through to stay with is temperature range.
  The carter man stated that he has heard of a few people with really old low HP cars in hot areas, on hot days, stuck in long parades, have pump problems. It is rare, but if you want to make sure that it never happens, then put the return line in with the orifice.
  

Best, James

[55 Fargo]

Several years back I talked with a tech at Federal Mogul (Carter). The topic was 6 Volt fuel pumps. He was very knowledgeable and this is what he said:

• Part Number P4259 works on 6 volt positive or negative ground.
  
• The rebuild kit (no motor) is part number 888-178.
  
• The pump has a maximum pressure of 5.75 PSI.
  
• This unit is a full time on unit and will not allow for a proper flow through if off. (use by itself, not with engine pump)
  
• This unit must be installed at a level equal to the bottom of the fuel tank.
  
• This unit must be within 2 fuel line feet of the tank.
  
• This unit typically drops between 1 to 1.5 PSI at the carburetor inlet. Less loss for shorter fuel line runs (Coupes) and more loss for longer runs (sedans).
  
• The only issue when using these pumps on small HP engines is as follows. These pumps must have 5 gallons of flow every hour to keep within operating temperatures. If you are at idle for over 30 plus minutes on a hot day in traffic and your engine does not pull enough fuel through the pump could overheat. The thing to do according to Carter is to put a fuel line tee up in the engine with a 1/8 or 3/32 orifice and a return line to the gas tank. That way the pump will always have enough fuel running through to stay with is temperature range.
  The carter man stated that he has heard of a few people with really old low HP cars in hot areas, on hot days, stuck in long parades, have pump problems. It is rare, but if you want to make sure that it never happens, then put the return line in with the orifice.
  

Best, James

Thanx for the detailed info James.

At this point I have not decided whether to just stay with my stock type mechanical fuel pump, or go with an electric type, I really dig the idea of the electric to deal with hot summer starts, when under hood temps soar, and mechanical fuel pumps can have problems delivering fuel to start....

[aero3113]

Fred, that's the pump I have installed.

[T120]

Hi Fred,Something to keep in mind, in the summer with a hot engine and a possible fuel percolation problem, attempting to restart after a shutdown, employing an electric fuel pump to refill the carburetor may actually aggravate the problem because the engine may already be in a flooded state....Now lets hear the arguments

[55 Fargo]

Hi Fred,Something to keep in mind, in the summer with a hot engine and a possible fuel percolation problem, attempting to restart after a shutdown, employing an electric fuel pump to refill the carburetor may actually aggravate the problem because the engine may already be in a flooded state....Now lets hear the arguments

I have had this very thought cross my mind to.

I have only had this problem on those days where it is over 30c 86f and humid, and under hood temps soar.

So you go for a nice drive, it's super hot, you stop for a bite to eat, then get back in car, that has been sitting in the scorching sun , and won't start.

The engine will of course start once things cool down, some Guys pour water over the fuel pump, I have had to let my engine cool then prime carb, and she goes.

I am in the market fora spare fuel pump, but have pondered installing a 6 volt electric fuel pump.....Fred

[55 Fargo]

Fred, that's the pump I have installed.

Keith How long have you had it in service, seems like a decent pump, Rock Auto price is decent too, at $46.00 CDN.....

[T120]

Hi Fred,I've only installed one electric fuel pump.I used it only for cold starts to fill the carburetor.It worked well for that purpose.It was in series with the mechanical pump ,which was used for driving.I have another electric fuel pump on the shelf,haven't had a requirement for it yet...By that I mean, none of the vintage cars I presently own have an electric fuel pump installed

Edited March 24, 2011 by Ralph D25cpe

[aero3113]

Keith How long have you had it in service, seems like a decent pump, Rock Auto price is decent too, at $46.00 CDN.....

I would say maybe around 250 - 300 miles

[James_Douglas]

If you put in the return line then the gas is COOL at the carb and when the pump kicks on the carb gets cool fuel.

If I use one of these pumps, I will put in a return line. My friend with a 1958 Cad says the AC cars had a return line even with the mechanical fuel pumps while the non-AC cars did not....Old solution to vapor lock and perculation....

James

[aero3113]

My original fuel pump (think it was original) was leaking oil from the vent hole. It still worked normal but the leak was driving me crazy. I now keep it in the trunk as a spare.

Vent hole on new pump

[JIPJOBXX]

I just carry a spare in the trunk! I think what came out in our old cars must have been the right stuff as look how long they have had mechanical pumps. Stock-stock-stock the way to goooooooooooooooooooooooooooooooo

[Tom Skinner]

All these old Mopars leak somewhere so a little at the Vent Hole in my Fuel Pump doesn't bother me. The other thing I was going to comment on is if its real hot out and you have turned your engine off for a short period - say at a gas station - then when re-starting just slowly floor the gas pedal to "clear out" the Vapors, while holding it to the floor hit your starter button and she should start right up - original fuel pump that is.

It takes a little learning each vehicle just like the old days - electric fuel pumps - be gone - as Wayne Dyer would say (L.O.L.) You don't gotta buy into all that malarky. Those electric fuel pumps just saturate your crancase oil, pumping it prety much continually into your carb bowl, which in turn dumps it into the intake manifold and runs down into your crankcase dilluting your oil. Changing Oil every 500 - 1000 miles would then be necessary - or risk cooking something in there. This is J.M.H.O. - please realize I don't really give a damn what you put under your hoods - my car is stock and starts great in the south when its 95 degrees out.

Tom Skinner

Huntersville, NC

[RobertKB]

I just carry a spare in the trunk! I think what came out in our old cars must have been the right stuff as look how long they have had mechanical pumps. Stock-stock-stock the way to goooooooooooooooooooooooooooooooo

I totally agree! Never had a problem with a stock pump except one that was infiltrated with filth from the gas tank. Totally my fault........not the pump's fault. Thought the tank had been cleaned thoroughly but thought wrong. It was 95+F and hotter than Hades under the exhaust manifold when I changed it. Fortunately had a spare one in the trunk. I have added a modern fuel filter under the driver's side running board since then. Again, no fault of the mechanical pump. That is me under the car.......not the advisor leaning over the fender.

Edited June 16, 2011 by RobertKB

[55 Fargo]

I totally agree! Never had a problem with a stock pump except one that was infiltrated with filth from the gas tank. Totally my fault........not the pump's fault. Thought the tank had been cleaned thoroughly but thought wrong. It was 95+F and hotter than Hades under the exhaust manifold when I changed it. Fortunately had a spare one in the trunk. I have added a modern fuel filter under the driver's side running board since then. Again, no fault of the mechanical pump. That is me under the car.......not the advisor leaning over the fender.

I enjoyed your Post Rob, I think for the most part these fuel pumps will be just fine, especially for the Canadian climate. On those super hot muggy days, which are short lived here in Southern Manitoba.

I am running either what is the original 1951 pump from the engine, or a pump that is at least 35 years old.

I did give it a clean up, and I installed a brand new gas tank, new lines and hoses along with a rebuilt carb and filters.

Since I have adjusted my float to approx1/8 of an inch below, and changed my accelerator pump linkage to the wrm summer setting, my engine runs, idles and re-starts much better.

I have not had 90 degree weather, but the other day it was about 82 and muggy, all was well.

My purpose for the other thread I posted was to bring light to another Mopar mans success with installing an airtex electric fuel pump, to be used as a primer, and auxilliary for hot weather starts.

Evidentlly this thread was attached to that thread by James Douglas, to reiterate others methods for dealing with percolation, gas vaporizing, and hard starts in hot weather, via a return line.

I hope my issues are solved, and will keep and eye on my fuel pump, and hot weather starts, and report any issues on here.

On another note, went for a ride tonight, to a local A&W Cruise night, but it was the wrong date, so just me showed up. It is cooler, but about 100% humidity, with a mist in the air.

I went for a higway cruise, had the car up to 65 mph, as verified by my GPS.

The engine ran and sounded fine, the suspension, well lets just say some work is necessary in the front end, and new rear springs would be in order too.

[55 Fargo]

Thanx for the post and comments, good advice. I reckon you Guys in NC have hot muggy summers, outta be good testing grounds for any old mechanical fuel pump.......Fred

All these old Mopars leak somewhere so a little at the Vent Hole in my Fuel Pump doesn't bother me. The other thing I was going to comment on is if its real hot out and you have turned your engine off for a short period - say at a gas station - then when re-starting just slowly floor the gas pedal to "clear out" the Vapors, while holding it to the floor hit your starter button and she should start right up - original fuel pump that is.

It takes a little learning each vehicle just like the old days - electric fuel pumps - be gone - as Wayne Dyer would say (L.O.L.) You don't gotta buy into all that malarky. Those electric fuel pumps just saturate your crancase oil, pumping it prety much continually into your carb bowl, which in turn dumps it into the intake manifold and runs down into your crankcase dilluting your oil. Changing Oil every 500 - 1000 miles would then be necessary - or risk cooking something in there. This is J.M.H.O. - please realize I don't really give a damn what you put under your hoods - my car is stock and starts great in the south when its 95 degrees out.

Tom Skinner

Huntersville, NC