FUEL PUMP RELAY

[87fast]

FUEL PUMP RELAY HELP

I HAVE A 87 LX 5.0 TODAY I TURNED THE CAR OFF AND THE FUEL PUMP KEEP RUNNING.I`M PRETTY SURE THE RELAY IS BAD HAVENT CHANGED IT YET HAD TO FIND LOCATION FIRST.TO TIRED TO CHANGE RIGHT KNOW AFTER I FOUND OUT WHERE IT WAS .MY QUESTION IS WHEN IM GOING DOWN THE ROAD AND HIT A BUMP THE CAR ACTS LIKE IT IS GOING TO STALL.
WILL THE RELAY CAUSE THE FUEL PUMP TO SHUT OFF AND COME BACK ON AND WILL A ONE OR TWO SECOND DROP IN FUEL PRESSURE CAUSE THIS.WHEN IT HAPPENS IT CAUSE`S THE CAR TO JERK PREETY HARD WHEN IT CATCHES BACK UP.THE FUEL PUMP IS ABOUT A YEAR OLD BUT NOT USED IN THE LAST 9 MONTHS HAD THE TOP OF THE MOTOR APART FOR MODS .THE PROBLEM WAS THERE BEFORE THE MODS BUT WENT AWAY AFTER WE SPRAYED THE TPS OFF WITH CONTACT CLEANER .

 

[87fast]

RELAY IS BAD TOOK OUT AND PUMP WENT QUIT RUNNING

 

[ECU5.0]

put a new relay in it....like 9 bucks from a parts store. dont know what to tell you about the other problem though

 

[87fast]

PUT NEW RELAY IN WENT DOWN THE ROAD AND SHUT OFF.RELAY IS HOT THINK PUMP IS GOING BAD .SOMEONE HELP

 

[ss93cobra]

The relay will get a little warm since it's under the drivers seat close to the exhaust. Anyway, your second post mentioned that you removed the relay and the car stopped running. That is what should have happened. As far as the electrical part, power goes from the relay to the fuel pump shut-off switch in the hatch cargo area (inside in front of the driver's side tail lamp) and then to the pump. As fas as the mechanical portion of this, have you checked the fuel filter or the fuel pressure? The stalling,jerking part could be caused by a plugged filter or a weak pump producing low pressure. Can you give more input on what you've done? When the car stalls out, can you hear the pump still running?

 

[v8only]

turn the caps lock off, it's like you're yelling at us, and it's hard to read.
in an 87, the relay is under the drivers seat. Be sure that it is fastented to the floor board good, and that all wires are tight and very snug. In my brothers 86 gt, everytime he moves the seat around it tugs on one of the wires that sometimes causes it to kill.

If you have a problem that happens when you hit bumps in the road, that sounds to me like a loose or faulty connection. Check the wiring all the way out to the gas tank, and check all grounds. It may be a bitch to find, but that is where I would start at least.

I have had my ignition switch (that I put the key into) go bad, and when that does, it won't supply any power to the fuel pump, so that's something to think about too.

 

[ratrapp]

my stang did the same thing so my nobrainer test was simple.with my car running i got out and kicked the gas tank a couple of times and the fuel pump would cut off and start up again.bad fuel pump.also it wouldn't hurt to replace the inertia switch(fuel pump kill switch)as they seem to fail at the worst times and they aren't very expensive.