is my fuel pump going bad?

Hey guys,

lately my truck has been acting up and i'm not sure what the problem is. my friend said it could be my fuel pump because i ran my tank completely empty a couple of times and that is bad for the fuel pump.

anyway, tell me what you think it could be. every once in a while maybe once every two weeks i'll go to start my truck from a cold start on flat with plenty of gas in my tank and it won't start. it just cranks over. after trying for a couple of minutes it will finally start but will bogg and stall. if i give it gas it will bogg a little but than rev up but when i try to let it idle it will either stall or idle at like 300 rpms instead of the normal cold start 1100 rpms. after letting it run at 300rpms for a second or two i rev it up to about 2 or 3 grand and hold it for a couple of seconds and gently let it come back down to idle than it usually idles normal and thats it. no more problem for a week or two. the weirdest thing is when it is idleing at around 300rpms the engine is VERY quiet and does not idle rough at all. it's almost like the engine isn't even running or something, kinda wierd.

anyway can anyone help me on this before i take it to the shop. but even if i take it to the shop i can't get it to do the problem they will say there isn't anything wrong with it ya know? lol

Have you tried replacing the fuel filter? especially if you've run it dry a couple times....

i had a similar thing happen last summer

and it turned out to be the fuel pump and the related tubing. i got it all replaced and my problems went away. i had trouble every morning - or after the truck sat for a long time. the mechanic told me that the fuel line would lose pressure and it would take a little bit to build back up - thus the constant cranking. my mechanic charged me in the area of $500. i don't know if that's good or not, but it's done and everything works.

az

anybody else have any thoughts on this problem i'm having?

I think on that year

The fuel pressure is measured electronicaly and it adjusts the voltage going to the pump. So you could have some electronic or connection problems, if it is the fuel system.

could be fuel pump, alo could be filter or even your tps. sometimes when the fuel pump starts to go you can hear a slight whistle sound ........sometimes

UPDATE:

the same problem has happened a couple of more times lately. I just happened to have my X in the shop for brakes and rotors and it did it for my mechanic. it is going back into the shop thursday and he will fix it. i will give a update when i find out what the problem was.

Before you go through the trouble and expense of dropping the tank, I'd check the fuel filter and fuel pressure regulator; both can get messed up (as can the pump) by running the tank dry.

keep me posted cause i have the same problem every once in a while, mine happens after it is warmed up sometimes, and if i shut it off and turn it on real quick it will go away?!

my 95 4.0 is messing up real bad too . i wondered if i was going to make it to work yesterday . i just bought the truck last week . it has 104k miles and when i was driving it home it felt like it started missing out (engine was that is) while i was going down the interstate . it just did it a couple times for a few seconds each time . its done it a few times since but yesterday it was down on power and missing out for about 10 miles . then as fast as it started it went away and ran fine . ran fine all the way home . this morning it did it again for a mile or two then went away again...
im going to my parents house today to steal the iac off thier 95 EB to see if that helps . i cleaned the MAS yesterday and that didnt help either . im going to replace the fuel filter today too .
i just hope its not the pump.. the tank looks like a real pain to get down . (im assuming the pumps in there)

oh yea , last weekend i towed with it for the first time too . just a small open trailer with my two dragbikes on it . i get to the track and the truck wont idle anymore . after a bit it would idle about 300 rpm . then after it sat about 5 hours it was fine again

the fuel filter is getting replaced today .
any idea what the fuel pressure should be ? ill find a way to check it myself . i want to fix it today and i dont want to pay someone to do it .

thanks for the welcome , this site is awsome . few could compare to the tech info here !!!!

Sorry to say, but running your fuel tank completely dry is the worst thing you can do. All the debris in the bottom of the tank gets sucked into the fuel lines, which plugs them, and probably the pump too. Also make sure your not leaking gas out the back, cause the pumps tend to rust "out" and pee out gas (happened to me). Thats probably the worse case, but dont run the tank dry again.

jee, my fuel filter is 9 years old... it has rust on it

well , i just replaced the iac , mas and the filter . checked the tps too . its running terrible , barley pulls its self , sorta like i pulled 3 plug wires off .
i still havent checked the fuel pressure . had to walk way from it for a minute....

ok , heres a lesson in "dont overlook the obvious"

apparently my plugs were the originals.. over 100k on them . the ground electrodes were radiused and tapered and basically trashed .
new plugs... fixed it right up !

oh yeah, i had one of my cylinders just not fire when my plugs were bad, you should have seen the plug, ick it was nasty. new plugs bam all fixed

Problem solved

I had my mechanic look at it. He said he hooked it up to a "scan tool" and found the IAC (idle air control valve)to be the problem. he said it was stuck open or something like that. the part was around $80 idles fine now and no other problems.

jee my stock plugs and wires were at about 120000km before i changed them.. i couldnt believe it still ran!!!

Hey holty...did you get that problem figured out?

These guys are right...change the fuel filter and the FPR first...they are both really cheap and easy to do in comparison to pulling the tank. You can do both of those in the same day for half the cost of the pump. FPR is really easy as long as you remember to depressurize the fuel system first. Sure I have kept a fire extinguisher in my ex ever since I changed mine, but its been 3 years...no fire yet.

good luck