Fuel pumps not lasting

[SKISPEED]

I have a jeepspeed that I run the stock pump inside a jaz cell. I have two in the tank one for a backup in case the first one goes bad.

This weekend in Mexico the first pump took a dump shortly after dumping some pemex in the tank. We said no problem we have a second pump. We switched the terminals and feed line and started the jeep back up. Ran great no problem. We went about 3 miles and the second pump went out. The first pump had about 3 races on it or about 500-600 miles then second pump went out after 3 miles??!!!!

WHY?

Is it something in the fuel? I had a similar situation happen last year at Parker . We put in some 100 octane from the local station and while driving through contigency the pumps both gave out.

I am now thinking of running the two internal pumps and a third external pump just in case.

The stock pumps in car last for years why are these going out so quick?

Any have a good explaination?

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[manicmechanic]

Some fuel systems are setup so most of the fuel goes to the pressure regulator and the back to the tank. If the pump is designed for that system and is dead headed in a different system maybe the pumps wont take it.
The return from the pressure reg disapeared on the Mopars around 1989 Those pumps generaly where a unit with its own reservoir built in and no baffles in the tank and no return line. They also hit about a billion rpm when you run out of fuel and wont take that to many times or for long.

[SKISPEED]

i guess i should add that my fuel system goes from the pump and tank to a pressure regulator there is a return line from the pressure reg to the tank. the remaining fuel goes to the fuel filter and then to the engine.

[SKISPEED]

COMMON CAUSES OF ELECTRIC IN-TANK
FUEL PUMP FAILURES

CONTAMINATED FUEL
Fuel tank contamination is the number one cause of in-tank electric fuel pump failures. This contamination is often the result of moisture in the fuel tank leading to fuel tank oxidation,causing rust to form in the fuel tank. The rust is then ingested by the fuel pump, ultimately bringing about pump failure.

A widespread misconception is that the fuel pump strainer or sock on the inlet side of the fuel pump will prevent these contaminates from entering the pump. WRONG! Fuel pump strainers will not stop moisture or particles of contamination smaller than 70 microns (on average). Why not simply use a finer filter strainer and eliminate these problems? If a strainer was made fine
enough to keep out all of the contaminates and still allow proper fuel flow volume, it would be too large to fit in the fuel tank. The strainers used today are a middle-of-the-road balance between allowing adequate fuel flow and maximum fuel filtering. Original Equipment and After-market replacement pumps are built to supply high pressure fuel to injection systems and are engineered with the assumption of a clean, cool, fuel supply to the pump at all times.

Injection systems are even more sensitive to contaminants; that’s why the industry standard is in-line fuel filters that capture, on average, particles approximately 30 microns or larger. Further downstream in the fuel system, fuel injector filters capture particles as small as 10 microns.

So it becomes obvious that any contamination in the fuel tank can cause premature fuel pump failure. (See TEC Bulletin #1620 for proper fuel tank removal and cleaning procedures.) If you find you are replacing a fuel pump that has a discolored strainer, properly dispose of the fuel you drained; it is contaminated too. If you put the same fuel back into the tank after the pump is replaced, you are reintroducing contaminants immediately! Always replace the fuel pump strainer and fuel filter with new units when replacing a fuel pump.


ELECTRICAL CONNECTIONS
Electrical connections are the second most common causes of fuel pump replacement. In reality, the fuel pump is still quite capable of providing pressure and flow well within specifications,but because of poor electrical connections the output is diminished, giving the appearance of a failed pump.

To identify fuel pump electrical problems, use a high quality digital volt/ohm/meter to test for voltage drops and continuity. This test must be done with the pump running. (See TEC Bulletin #1620 for how to test for voltage drop.) NOTE: In a 12-volt system, fuel pumps are designed to run at 13.5 volts. Maximum voltage drop of more than .2 volts will affect the fuel pump operation.

[manicmechanic]

The stock setups I have seen have the filter before the regulator so they filter the return fuel as well as whatever the engine is using. So maybe when you do get bad fuel it goes through the pump again and again instead of plugging the filter.

[SKISPEED]

sorry was looking at my system last night and it does go through the filter first before the regulator. I was just going by memory not the best thing.

[SKISPEED]

so not sure if anyone cares but here is the correction for my problem... "eight inches of black fuel line" The first problem was replacing fuel pumps in a race car at midnight the night before Parker. It seems one of the hose clamps that held the hose to the fuel pump in the tank was not properly secured and worked its way loose. The second was once the brillant driver found that first pump had no fuel pressure he switched the electrical connector and then tried to start the vehicle but "forgetting" to move the feed line from one pump to the next. The attempted start sent 60 psi to a dead end and caused the second "50psi" rated line in the tank to rupture. Hence the lack of fuel pressure in the second pump. The lines have been replaced and pressure restored and the vehicle now runs flawlessly.

case closed and repairs under $100.00

[Dezertpilot]

Always good to have a quick and easy fix to your problem.

[manicmechanic]

Thats why I always smoke a cigerette while changing fuel pumps, It calms me down so I dont make mistakes !!!!!!

[Shannon]

so not sure if anyone cares but here is the correction for my problem... "eight inches of black fuel line" The first problem was replacing fuel pumps in a race car at midnight the night before Parker. It seems one of the hose clamps that held the hose to the fuel pump in the tank was not properly secured and worked its way loose. The second was once the brillant driver found that first pump had no fuel pressure he switched the electrical connector and then tried to start the vehicle but "forgetting" to move the feed line from one pump to the next. The attempted start sent 60 psi to a dead end and caused the second "50psi" rated line in the tank to rupture. Hence the lack of fuel pressure in the second pump. The lines have been replaced and pressure restored and the vehicle now runs flawlessly.

case closed and repairs under $100.00

O.K. good to know if your still reading !! But listen , first of all regulate your P.S.I as said previous,Ty all your in tank systems together, Make shure you have check valves on pumps so if one hose breaks it won't kill whole system!! you can still run outside tank inline,take the time to run power to each pump stand alone,making it driver proof. Trust me we had same problems cost me a finish !!! Never Again!!!


Good quality fuel pumps help also !!!!