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2007 Kia Sportage
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Discussion Starter #1
Hello all,

I have a 2007 model Kia Sportage that has had a few engine starting problems recently. In the engine compartment near the battery is a fuse and relay panel, one component of which is labelled as a fuel pump relay. Any idea what the purpose of this fuel pump relay is and how it functions?........
 

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2015 Buick Verano "Leather Group", 2015 Kia Optima Hybrid
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A fuel pump relay takes control of the fuel pump during engine startup, but shuts itself off after the engine is running.
 

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2007 Kia Sportage
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Discussion Starter #3
A fuel pump relay takes control of the fuel pump during engine startup, but shuts itself off after the engine is running.
Interesting... On two occasions in the last couple of weeks, my 4cyl 2007 Sportage stalled about two seconds after startup and would not restart. After the first instant, about 10 days ago, the local dealer replaced two sensors; a crankshaft position sensor and a TDC sensor as well as installing new spark plugs.

The vehicle then ran fine for about 10 days after which the problem returned - stalled about two seconds after startup and would not restart. Again the local dealer took a look at it. They "jumped" (in their words) the fuel relay to activate the fuel pump to get it started and now it seems fine again.

The dealer indicated the problem may be due to the configuration of the fuel pump and fuel tank. The fuel pump is mounted inside the fuel tank, which has two wells. I live on a Caribbean Island which is very hilly. The dealer recommended keeping the fuel tank over half full rather than less than half full due to the effect of driving up and down hills has on the fuel pump and it's ability to pick up fuel while going up and down the hills.

However, both times that the engine stalled were after driving on relatively flat areas with about 1/3 tank of fuel?? I am wondering if there might be an intermittent electrical problem with the fuel pump or its wiring?

If the fuel pump relay takes control of the fuel pump during start up only, what takes over after the engine is running and the relay shuts down?

Thanks for your input!
 

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97 Jeep 96 Dodge Ram
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If the fuel pump relay takes control of the fuel pump during start up only, what takes over after the engine is running and the relay shuts down?

The fuel pump relay does not function only during start up. It functions whenever the engine is running. When you turn the key to on, the ECM gounds the control circuit for the FP relay. This activates the relay and the pump runs for a couple of seconds. You should hear the pump run when near the fuel tank. This brief run time primes the fuel system ready for starting. The ECM turns off the relay if no start action is taken.

When you turn key to start, the ECM checks all the sensor info and turns the relay on for engine running operation. The relay is on when the engine is running. The relay feeds electrical power to the fuel sender and fuel pump motor.

What the dealer did is use a short jumper to jump pin 30 and 87 to get power to the pump for troubleshooting.

I would think that KIA would do some kind of incline test to see if the engine runs while on hilly terrain. Not sure I believe what they said. If true, there should be some warning in the owner's manual.

You may want to change the FP relay in case it may be going bad. Next time you have a no start problem check to see if you are getting a spark. Most no start problems is either spark or fuel related. There are a few sensors that relate to these 2 systems. If you have spark you can concentrate on fuel.
 
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