fuel pump???

[joe doe]

ok guys ,its been hott the past few days ,in the triple digits.i thought this might be the problem with my ex sport bogging down and losing power .

i replaced the iac valve and thought my problem was over.
well today after driving quite a distance in the heat it started bogging down and losing power and stalling again .

i put my thinking cap on and said to the wife ,lets go put more gas in it .we were just under a quarter tank at the time .

we put 20 bucks in bringing the level up over a half tank and it ran fine again .even in 100 degree heat .seems when we get down under a 1/4th tank we get the stalling/bogging/bucking problems.

when i mentioned this to my mechanic he said sounds like the fuel pump.

what you think???

would it really make any difference the amount of gas in the tank has to how the fuel pump is pumping??

under a 4th bogging and bucking and stalling .
throw a half tank in there and she runs fine be it high heat,a/c on ect,ect...

thanks guys

 

[Explorer Junky]

the fuel pump could be over heating due to the fact that under a 1/4 the gas is NOT getting slashed on the pump as much. So when you put that nice cool gas in there the pump gets cooled off. Most pumps fail due to the fact that a lot of people run there cars almost empty. Thats why i keep on my wife about not waitng til her van is almost completely empty before she fills up. Burns the pumps faster. Just MY opinion. Yes could be the pump!

 

[joe doe]

thanks man .yes we run it low alot .seems like its always near empty.these 4.0 ohv v-6`s are not that good on gas .

 

[Explorer Junky]

NO Prob!

 

[joe doe]

well still not convinced i have a fuel pump problem .after the heat wave passed the fuel pump seems to be working fine .i even ran it to empty to be sure .
i did get a number 4 cyl misfire recently and thinking it was my wires (the plugs are only couple months old)i replaced them .still had the misfire .
cleaned the plug in question.
still had the misfire .
replaced that plug with a new champion(autozone recommended another autolite plug at 6.99 each)and the misfire went away .

could it be that the extreme heat (101 that day)gave me a case of vaporlock?and when i added more gas to the tank (cooling the gas in there with fresh gas)the problem went away?

one thing after another with this truck here lately.