Fuel Pump?

[RustedRanger]

Last week I almost ran out of gas and when I turned a corner it started missing badly...then after putting gas in it still does it off and on. Think I killed the fuel pump? The filter only has about 6,000 mi on it and the gas tank shouldn't have had much dirt in it since I replaced it a couple years ago. I put dry-gas in it when I got gas. The truck has 170,000 mi on it and it don't look like the pump has been changed. There is no filter in the cannister in the frame rail. This sucks highly because I am out of work.

 

[RustedRanger]

Nobody here has had a fuel pump go out? I find that hard to believe. I keep coming here every day so I might be able to help someone who has had the same problem(s) I have had.

 

[IMenriched]

Nobody here has had a fuel pump go out? I find that hard to believe. I keep coming here every day so I might be able to help someone who has had the same problem(s) I have had.

there probably no filter in the canister...it is more of a reservoir, for high demand .

you are aware that you have 2 fuel pumps...unless it has been changed from the factory. 1 in tank & one on the rail.

can you hear the Fuel Pump (FP) prime when you turn the key on, ( not all the way to start) ?? it should be on only briefly 2-4sec

 

[RustedRanger]

Thanks IM, there is no filter in the cannister because I had it apart before I knew where the "real" filter is and when I replaced the gas tank I got the pump that was with it because it looked pretty new,I know there are two. Yeah,I can hear the pump run and shut off. It has had a problem for awhile with starting again if I killed it on take off. It is still running but takes spells where it misses real bad and it's getting worse quickly. Last time I drove it was Sunday coming home from church (about 20 minutes) and it missed out almost the whole way home. The main reason I believe it is the high pressure pump is that I ran it low on gas and it started missing when I turned a corner like it was out of gas and it runs decent at light throttle then misses when I try to give it gas. Thanks again IM.

 

[IMenriched]

Thanks IM, there is no filter in the cannister because I had it apart before I knew where the "real" filter is and when I replaced the gas tank I got the pump that was with it because it looked pretty new,I know there are two. Yeah,I can hear the pump run and shut off. It has had a problem for awhile with starting again if I killed it on take off. It is still running but takes spells where it misses real bad and it's getting worse quickly. Last time I drove it was Sunday coming home from church (about 20 minutes) and it missed out almost the whole way home. The main reason I believe it is the high pressure pump is that I ran it low on gas and it started missing when I turned a corner like it was out of gas and it runs decent at light throttle then misses when I try to give it gas. Thanks again IM.

I had very similar experience with mine....I got much more reliability when I opened up the gas tank...to replace the "in tank" pump....the big issue for mine was the short piece of rubber hose between the pick-up sock & pump to the stem pipe, which sends fuel out to the tank. this short section of rubber hose was about 2-3"....and was completely gone. shucks the fuel pressure even tested OK, toward the bottom of the spec but ok...If I recall correctly, 31-32psi

I could have replace the hose and maybe gotten by on the cheep. BUT I had already bought the fuel pumps...but only replaced the in tank pump. which cured a world of issues. I then could drive more than a 20 mile radius from home without run-ability problems and more noticed, was that I could have less than a half a tank of gas without compounding the problem. It would always start completely cold without any hesitation, everything would change after it would get fully up to operating temp. I would stall and not restart, spit & sputter... IF I let it sit for 1/2hr to hour it would start again and then I could drive home. Sound familiar? The symptoms mimic the TFI ignition module problem pretty closely .

you may already know this, but I had very good luck replacing the in-tank pump by taking the box off.

Now this may not be the issue with yours...but you do need to check it

 

[RustedRanger]

Well if I kill it and have to re start it it's hard to start when cold,it has happened a few times. I replaced the tank and the in tank pump at the same time,they came from the junkyard but was still clean and shiny so they wasn't very old. The hose between the pump and sender is good...I do remember that clearly. It misses when I give it gas both when it's cold or hot. I have only driven it twice since the day I almost ran it out and I put some dry gas in it when I put gas in,I was hoping it was just some water in the tank when I ran it low but it acts the same as when it was almost out of gas. I just figured it was the high pressure pump since it looks original at 170,000 mi. Also....sometimes it fires right off cold and other times it don't and has to crank a bunch. Thanks for the info. I have tried to do a search here but for some reason it won't work...gives me 505 server error or crashes the browser.

 

[alwaysFlOoReD]

I just went through a similar problem in my b-2 which has a 4.0 someone else put in it. I finally tracked down the problem to the 3" rubber hose between the in-tank high pressure pump and the float side of the in-tank pump. The previous owner replaced the pump on the unit and used I don't know what type of hose but it was loose and would bypass some of the fuel. So at the fuel rail at the motor it only had 20 psi. I added two hose clamps and the problems have disappeared. I'd suggest finding out what fuel pressure you have at the fuel rail. Some auto parts places have a loan a tool program and you could get a fuel pressure gauge and find out if the fuel pump is your problem.

Richard

 

[RustedRanger]

Thing is that it didn't happen at all until I turned a corner while almost out of gas and the hose is good and really tight,when I replaced the low pressure pump I thought it was going to bend the sending unit getting the hose on there. Thank for the info.

 

[IMenriched]

Thing is that it didn't happen at all until I turned a corner while almost out of gas and the hose is good and really tight,when I replaced the low pressure pump I thought it was going to bend the sending unit getting the hose on there. Thank for the info.

Have you tested the fuel pressure?? also when testing the fuel pressure leave the pressure gauge on for a hour or 2, checking for bleed back/off .

are you certain that you didn't crack the metal line...& that the hose on the "in tank" tank pump was fuel line hose, rated for gas, not just generic hose??

have you checked all the connections? grounds on these are most important, make sure they are all good.

 

[RustedRanger]

I changed the tank/fuel pump around 2 years ago. It's been running ok since then. I know something else could go wrong at the exact time I almost ran out of gas and turned a corner but it's unlikely so I'm still leaning towards the main pump getting starved of fuel and killing an already old fuel pump. thanks guys

 

[IMenriched]

I changed the tank/fuel pump around 2 years ago. It's been running ok since then. I know something else could go wrong at the exact time I almost ran out of gas and turned a corner but it's unlikely so I'm still leaning towards the main pump getting starved of fuel and killing an already old fuel pump. thanks guys

If you test the fuel pressure...it will give clues as to the health of the fuel pump/s....a less than scientific way to check the fuel pressure is to depress the schraider valve on the fuel rail, it will/should spew gas, so be ready with some rags, should be better if it wasn't running either, cold engine, before it has been started for the day for safety consideration.

cycle the key on ( not over to start) depress schraider valve..note how much gas spits out....if you get a stream squirting nearly to the roof. your pump is more than likely fine. And you may have a FPR (fuel pressure regulator) issue.

if you just get bubbles, or just barely burbling out...then yeah, the FP is very weak.

then try again after it has run briefly...shut it off...again depress the schraider valve...noting again the vigor of how fuel comes out... same rules apply as above

 

[Earl43P]

The truck "runs", so the high pressure pump is working.

The in-tank pump is a low pressure "lift" pump that delivers flow to the high pressure pump. Your symptom makes me believe the in tank pump isn't delivering enough flow.

Easy enough to test that theory.
Disconnect the electrical connector to the frame rail mounted high pressure pump.
Disconnect the outlet line from the fuel filter. Fuel will dribble out, so have a bucket ready.
Turn the key to Run and the flow out of the filter should increase and you should hear the pump in the tank run for a couple seconds.


If you don't want to disconnect the fuel filter line, do what I described except depress the schraeder valve on the fuel rail to gage how much flow the in-tank pump is delivering. You'll obviously have to relieve the pressure at the fuel rail before conducting the test.

 

[RustedRanger]

Thanks again guys...thanks Earl for the info...I can't afford to fix what isn't wrong lol I really hate the thought of taking the tank out...again. When I replaced the tank the first time the O-ring was bad and I had to do it again,at least if I have to take it off I know how to do it which makes it easier and faster...I hate messing with gas lol

 

[RustedRanger]

I replaced the lift pump and it ran worse....then the next day changed the fuel filter and it was badly clogged....no change...still ran bad. Then I changed the spark plugs and now it runs good again So....I do believe that even if the lift pump wasn't clear dead it was weak and the fuel filter was without a doubt clogged badly and the resulting low fuel pressure caused the injectors to not spray but squirt and killed the plugs. p.s. I did check the fuel pressure with a gauge and also checked that the FPR was working right...when I relieved the pressure at the schrader valve to check the pressure it didnt have much and it had a lot of air bubbles in it that I believe was caused by the high pressure pump having to suck the fuel through the cannister filter housing which doesnt have a filter in it. Thanks for the advice and info.

 

[Earl43P]

Glad you got it fixed!