Is my fuel pump going out?

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  • Indy_Guy_77

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    2006 Nissan Altima 3.5 SE. Almost 125k miles.

    After it sits for a while - be it over night or through a work shift (~8hrs) the car becomes difficult to start.

    Battery and alternator were just tested as "good" last Friday a few days after the first few initial hard starts.

    I generally always turn the ignition on and wait a few seconds for the fuel pump to build pressure. I can still hear it whine.

    The car takes 1-2 seconds of good strong cranking to finally turn over. There hasn't been any noticeable difference in vehicle performance at surface street speeds nor on the Interstate. No abnormalities in accelerating onto the Interstate, either.

    Off the top of my head, I do not know if/when the fuel filter has been changed. A car with this many miles, I'm almost certain that we have had it done. Air filter was recently changed.

    All ignition components are still OEM - as it's a $300-400 job to do the plugs & wires.


    So... Is my fuel pump going out on me? Other ideas?

    Anyone in Greenwood or on the east side able to do a fuel pressure test?
     

    GodFearinGunTotin

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    I'm not much of a mechanic but when the fuel pump went out on my GMC, it went out without any sort of warning.
     

    CountryBoy19

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    I'm not much of a mechanic but when the fuel pump went out on my GMC, it went out without any sort of warning.

    My GMC truck's pump went out without any real warning (it ran fine)... I knew there was some fuel issue going on (description below) but I wasn't aware it was fuel-pump related.

    Truck would start fine cold, would start fine after sitting a while (hour or more), but if it was hot and was left to sit 10-30 minutes it would start really hard (had to crank for a while). I rarely used the truck so I just dealt with it and assumed it was some sort of issue vaporizing the fuel in the rails driving back into the tank, once it cooled off the vapors condensed and all was well. Fast forward to when I'm working overseas a year or so later and truck worked fine up to a point then just wouldn't start at all, stranding my wife in town. The truck started fine to get to town, but wouldn't start for the return trip. It was the fuel-pump. I replaced it when I got home and the hot-restart problem went away.

    The symptoms presented by the hot-restart problem did not seem to indicate fuel pump issues, but apparently they were. Those issues seem somewhat similar to the issue you're having. I would recommend you get the fuel-pressure checked out.
     

    rosejm

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    I'm not nearby to help diagnose, but let's talk about the hard starting...

    Does it crank over quickly, but just take more revolutions than normal to fire or does it crank slowly?
    If you turn the car off, and try to restart does it start normally?

    You'd probably remember replacing the fuel filter, as it requires removing the back seat and pulling the filter from the inside of the tank.

    You say the battery was tested good, but how old is it?
     

    Mr Evilwrench

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    Had a fuel pump go out on a Malibu; it stopped in the middle of the interstate and wouldn't run at all. With the age/mileage, I'd look at plug wires just for PM. When the chicken (94 Thunderbird) is cold or wet, it has to start one cylinder at a time, so as soon as I figure out where I left the new plug wires I'm going to replace them. Do the plug wires yourself, it's dead easy. Plugs may be a bit harder, but you can do those, too. You won't have $50 in it. Replace the fuel filter, as well; if that's snotted up it'll cause trouble. Your fuel pump sounds fine.
     

    churchmouse

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    Some pumps will act like that but there is an enriching device on FI equipped vehicles that puts more fuel in the engine on cold starts. It is needed due to not having the old style choke. If this system is failing you will experience hard starts on the engine when cold.
    Fuel filter been serviced recently????
     

    rosejm

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    If it's the Intake Temp sensor, that would cause problems on cold days/nights.
    If it is a sensor issue, like you guys think, it's more likely the Water Temp sensor which would be the piece controlling fuel enrichment at cold engine starts.
     

    HoughMade

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    Could be fuel pump; could be other things.

    Injector leak down?

    Does your pump or FI system have a one-way valve that keeps fuel pressure up (or is supposed to)?
     
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    Indy_Guy_77

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    Two previous vehicles that had fuel pump issues - one was a slow fade over a commute and one was a DRT failure.

    Starting: It takes more "revolutions" to fire the engine than normal. It normally fires almost immediately. These days it'll take a few seconds.

    After it's been running and shut off, it'll fire up again quickly - as normal.

    I know that *I* did not change the fuel filter myself. I cannot remember if I've had it done as PM or not. I do know that nothing has been done to it recently (within the last 30k miles or so).

    *I* can't do the plugs myself. They're inside the intake. I don't have the skills / knowledge on how to replace the gasket well enough that I'd trust my work. If I had someone looking over my shoulder judging my work - sure. That's why having the plugs done on this car/engine is so blasted expensive. I DO think I could manage the wires...

    If it is some kind of sensor going wacky - would it throw a code? I can have the codes read pretty easily - and can google them up just as easily.

    Thanks all!
     

    scoutsniper

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    it could be throwing a code. id have it scanned for free just to check. but if its only happens during cold starts then it might not throw after its warmed up. it def sounds like a sensor. but id do a fuel filter first there cheap (like 10$) and just time consuming to do but hand tools is all you need.
     

    Indy_Guy_77

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    Small update: My car was shut off at 0705. At 1151, it fired right up.

    I don't know if that'd be considered a cold start or not...
     

    OneBadV8

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    *I* can't do the plugs myself. They're inside the intake. I don't have the skills / knowledge on how to replace the gasket well enough that I'd trust my work. If I had someone looking over my shoulder judging my work - sure. That's why having the plugs done on this car/engine is so blasted expensive. I DO think I could manage the wires...

    Thanks all!

    Doesn't look all that bad. You don't have to take your intake off to get to them. You just need a "spark plug" socket, the one with the rubber inside so you can get the plugs out.

    [video=youtube;91sAbo3M_f4]https://www.youtube.com/watch?v=91sAbo3M_f4[/video]
     

    rosejm

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    Should be plenty long enough to reach ambient temp.

    Bad sensor should throw a code, and usually you'll also see issues when driving not just starting.

    It almost sounds like the computer is forgetting the cam/crank angles and has to re-learn them during those 1-2 second starts.

    As you're not having trouble under hard acceleration/top speed and it starts normally warm, I can't think it's fuel pump/pressure. That should be easy to check if there's a pressure port on the fuel rail. Should be around 40-50 psi.

    My initial thoughts here lead to a Idle Air Control/Motor. This is the little plunger in the throttle body that regulates how much air enters when the TB is closed. Maybe a good deal of buildup/crud that is slowing/sticking the plunger and loosens up when warmed up.

    Might be worth the time to pull the intake and change the plugs. 125k miles is a long ass time on a set of sparkplugs. Run some TB cleaner or spray Seafoam through the TB and intake while it's apart.
     

    rosejm

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    Doesn't look all that bad. You don't have to take your intake off to get to them. You just need a "spark plug" socket, the one with the rubber inside so you can get the plugs out.

    Damnit. So that video looks like the 4-banger version. The 3.5L is a V6 and I'd bet the plugs on the back side of the engine might be tough to get to.

    It does look like the Intake plenum/manifold will need to be removed, and the gasket changed. Shouldn't be tough to do, but isn't as easy as removing wires/coilpacks and R/R plugs.

    This is on a Quest, but I think the same stuff applies:
    [video=youtube;i7wdmCGoyhE]https://www.youtube.com/watch?v=i7wdmCGoyhE[/video]

    Steps & Pics for a manifold spacer, which is going to be nearly the same (add plug steps) for removing it to gain access to the plugs.
     
    Last edited:

    Mr Evilwrench

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    My problem is not with just cold, it's with cold/wet. The insulation on the plug wires will degrade with time, and moisture will cause leakage. This is a high voltage system, so leakage is a bad thing. A little heat, and the moisture is driven out, no more problem. The plugs themselves are a lot better than they were 50 years ago, so you can probably get away without messing with them. The insulation is better, but it still starts leaking eventually. You have enough years and miles on it it should be done, even if this is not your problem right now.
     

    OneBadV8

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    Don't they have a dog bone mount where you can rock the motor forward? Most cars have one that are like that, at least the American cars I've worked on. I would bet it can be done without taking apart half of the motor though.
     
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