Aloha all,

I just got done doing an 4.2L engine swap in my 04 S-Type. Car cranks over but is not getting any fuel to the rail. All fuses and relays related to fuel pump are all good. Do you think i need to flash the ECU (have not done yet) to get the fuel system working? Any help would be greatly appreciated.

 

If it's the same kind of engine you don't need any reflash.

 

@JagV8 thanks for the response. I didn't think I neededto reflash but thanks for confirming. I will work on figuring why I'm not getting power to the fuel pumps.

 

If your car is not supercharged, then you only have 1 fuel pump. It is located under the right rear seat. It has a 4-pin electrical connector on top - 2 pins send a resistance value from the float to the computer reporting the fuel level in that side of the tank; the other 2 pins receive voltage to run the pump motor itself.

AllData and/or JTIS probably has some diagnostic protocal for testing a potentially dead fuel pump. So check there for answers if you haven't already.

I am NOT an electrician, but I would put a volt meter on the corresponding female connectors for the 2 pump power pins, as this is the pump's power supply. If I see no voltage when the car is cranked, that indicates no power is getting to the pump and I'd look further up the electrical system for my problem.

On the other hand, if there IS power to the connector when cranking but the fuel pump motor is not whirring away, it would suggest to me that the fuel pump motor is dead.

Again, I am NOT an electrician. Am just trying to follow the problem logically based on my personal experience with the '03-04 non-STR fuel pump system.

BTW - if you decide to remove the entire fuel pump assembly from the RHS of your fuel tank, you must first remove the sending unit assembly from the left side of the tank and disconnect the transfer hoses attached to the bottom of it. They are part of the RHS fuel pump assembly. BE VERY CAREFUL! You don't want to damage the float mechanisms of either RH or LH assemblies, as that will create an entirely new set of problems for you.

 

Did some testing and fuel pump was DEAD. New one coming in Monday. Let you guys know how it goes. Thanks for the help.

 

Good luck. Please do let us know how it goes.

 

If fuel pump doesn't work for awhile(engine replacement), it can get stuck. Remove it and knock it with a hammer slightly. Hook it up to a battery with jumper wires to check. If it still doesn't work, try again harder, you have nothing to lose.

 

There is a pump in left side of tank, it is jet pump, not electrical one. Part of fuel flow from electrical pump goes to left side to operate jet pump. Jet pump moves fuel from left side to right side..

 

Changed out fuel pump. Cat fired right up. Thanks for the help. On to the next project.

 

Not correct. The left side in a non-supercharged '03-04 car does not contain a pump. It contains the "sender unit" -

https://oemdiscountcarparts.com/part...&siteid=218637

- which is nothing more than a spring-loaded telescoping plastic tower with 2 hose connectors pointing vertically up (to which the transfer hoses from the right side pump attach); a fuel inlet opening with a large rectangular filter on it; and the float/level sender assembly. That's it. There is absolutely no pump of any kind on the left side of the tank. Any pumping action is done from the fuel pump on the right side, via the transfer hoses.