Bad hessitation; Vapor Lock maybe need help.

[ucf_motorcycle]

Ok I posted this in the problems section but no one replied. THe truck runs like crap after long drives and I want to know how to fix it.

So I just did an 850 mile trip. The truck ran fine up until it got to about half a tank. At this point I hit the throttle to pass someone and the truck would not go past 4000 RPM it was as if there was a rev limit there. I continued driving for a while longer just keeping constant throttle and the truck ran fine at about 75MPH. Then the truck reached less than a quarter tank and it was time to get it gas. I decided to see if the problem was still there and I stepped on the throttle this time it was even worse as the truck would not go past much more than 3000 RPM. After I got gas the truck was back to normal.

It ran fine again up untill about a half a tank again. This time I kept flooring the truck periodically to see if I could duplicate the problem again. It did it again at about half a tank. And every time after that point if I stepped on the gas it would do it. I decided to to pull over and shut it off for a minute to see if that helped. It did. The truck ran fine for a while after that. But then it came back again.

I realize that this is an issue that would only come up with LONG distance non stop driving.

I have a theory that it may be due to a fuel venting/vapor lock type issue.
Does anyone have any knowledge on how to fix this?

[RB's Titan]

What year truck?
Where you towing?
Were there any SES lights?
Has the truck been wrecked?
Did you tighten the gas cap?

1. 04's have known issues with fuel pumps
2. If towing sounds like truck was hot.
3. If lights on then for sure truck was hot.
4. If truck has been wrecked and tranny lines pinched your tranny could be hot.
5. Some gas caps have failed could be reason.

Take it in and have it checked out.

[ucf_motorcycle]

Its a 2004.

Was not towing, (I had about 800lbs of cargo shouldn't be an issue) no lights, no warnings, all guages in the norm. Made sure the gas cap clicked when I filled it up the second time.

Oh and my truck has 77,000 miles so its out of warranty, I'm not taking it in if I don't have to.

So any ideas?

[RB's Titan]

Originally Posted by ucf_motorcycle

Its a 2004.

Was not towing, (I had about 800lbs of cargo shouldn't be an issue) no lights, no warnings, all guages in the norm. Made sure the gas cap clicked when I filled it up the second time.

Oh and my truck has 77,000 miles so its out of warranty, I'm not taking it in if I don't have to.

So any ideas?

fuel pump....get a guage and check pressure at fuel rail at run at 15oo rpm should be 51-54psi.

[HudsonValleyTitan]

Originally Posted by RB's Titan

What year truck?
Where you towing?
Were there any SES lights?
Has the truck been wrecked?
Did you tighten the gas cap?

1. 04's have known issues with fuel pumps
2. If towing sounds like truck was hot.
3. If lights on then for sure truck was hot.
4. If truck has been wrecked and tranny lines pinched your tranny could be hot.
5. Some gas caps have failed could be reason.

Take it in and have it checked out.

What known fuel pump issues? There are none for the 04s according to Nissan. There was a TSB for the fuel sending unit but that's a fuel guage reading issue only.


http://www.nissanhelp.com/Bulletins/Titan/2004/1.htm

[chris_lee]

Strange.... See my post near the top about transmission problems durring off roading. Sounds like the same symptoms? Hmmmmm

[RB's Titan]

my dealer has replaced 3 fuel pumps so far on 04's. So they say...maybe they wanted to replace mine for some cash. just a relay based upon my experience. I think I read about a fella driving to alsaka that had a fuel pump issue too.

[Voodoo]

my fuel pump went bad at 15k, and my cats went bad at 17k.

when my fuel pump went bad it would not go above 2500rpm and it would buck and sputter and sometimes the go pedal would not even respond.

hope you get it figured out. might want to call your insurance and have them add roadside assist if you dont have it already.

[konigfritz]

I was just thinking of you Voodoo, Yes sounds like a fuel pump issue.

[ucf_motorcycle]

So if its the fuel pump why would the problem go away by shutting the truck off for 2 min?

In my experience fuel pump problems get worse as the fuel level gets lower in the tank but it doesn't go away after you let the truck sit.

I'll have to check the fuel pressure when I get back in town in two weeks, but I would be surprised if that was the issue.

[ucf_motorcycle]

Originally Posted by chris_lee

Strange.... See my post near the top about transmission problems durring off roading. Sounds like the same symptoms? Hmmmmm

Yeah after reading your post it sounds like both our trucks were having the same problem only in different situations. I am wondering if there is a fuel vent somewhere that could be clogged and causing this problem Only reason I am stuck on this fuel vent thing is because I had a motorcycle that had a crimped fuel vent hose and the symptoms were similar.

[garyk211]

My truck started doing the same thing, hit passing gear and it feals like its running out of gas. Next day its fine. Was it a fuel pump problem or something else??

[boya544]

Sounds like the fuel pump. My 02 Frontier did the same thing would run fine if I kept the gas tank above half.If I let it go past that it would act like the rev limiter was on at around 3500rpm.Nissan replaced the fuel pump and now she runs fine.I asked why the fuel level would effect it.They told me the added pressure of the weight of the fuel helps the pump suck up the fuel.

[HudsonValleyTitan]

A bad fuel pump is a bad fuel pump. There's no reason the pump would work fine for the 1st half tank and then suddenly crap out...tank after tank. Some sort of vapor lock due to a bad charcoal canister system would be my first bet.