# car shuts off when i touch the accelerator pedal



## coreyzapf (Mar 4, 2018)

so far I have tried a number of things but as my car reaches operating range it dies. In the last week here is a list of everything I have had to change on my 05 Nissan Altima 2.5 s 

Throttle body
MAF
serpentine belt
starter 
alternator
spark plugs
coil packs
cam shaft position sensor
battery

Car idles ok but once I touch the gas pedal the car shuts off, I have also verified that my fuel pump is working Can some one please help


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## quadraria10 (Jul 6, 2010)

All in one week? That seems super excessive. My guess is that it needs to do an idle relearn procedure. Are you not getting error codes? Why have you thrown so many new parts at it. The crankshaft sensor is a known issue with that engine, so I am surprised that was not on your list. Based on age I would have done the tensioner for the serpentine belt.


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## coreyzapf (Mar 4, 2018)

quadraria10 said:


> All in one week? That seems super excessive. My guess is that it needs to do an idle relearn procedure. Are you not getting error codes? Why have you thrown so many new parts at it. The crankshaft sensor is a known issue with that engine, so I am surprised that was not on your list. Based on age I would have done the tensioner for the serpentine belt.


Well I have changed those parts due to my own ameteur mistakes of listening to friends. And letting friends work on my vehicle has cause some of these too break. Curious to what the serpentine tensioner would have to do with my problem though. And i am not receiving any codes.


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## BlownSkillet (Mar 6, 2018)

I would bet my next pay check that THIS is your problem.

Accelerator Pedal Position Sensor (it comes as one unit, petal & sensor)


I actually got mine locally at Advance Auto Parts, by ordering on-line and receiving a 20% discount. They had it in stock, at the store. 

I have a 2005 Altima, and have changed this little booger twice, in 257,xxx miles. Most threads and videos, will say that you have to "reprogram" the petal before it operates correctly, but in my case, a 5 minute removal & replacement of the throttle petal & sensor (comes as one unit) and the car ran and accelerated perfectly. Give it a shot, and reply back to us. I would be SHOCKED if this is not your problem.


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## quadraria10 (Jul 6, 2010)

Bad belt tensioner will affect the charging of your battery by the alternator, and or cause your alternator to fail early. I was just noting that you had changed the serpentine belt, alternator, and battery. Here is some info on its role.

Automatic Belt Tensioner

With regard to the accelerator position sensor (think its also the throttle position sensor) I would think a bad one would set off a malfunction code. If you changed or disconnected your throttle body to clean it, I am pretty you have to do a relearn procedure for it. If that was not done it could well be the issue. You should be able to find the procedure by googling it, or you should be able to find it in the factory service manual for your model.
https://ownersmanuals2.com/make/nissan/altima-2005-4262


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## BlownSkillet (Mar 6, 2018)

The sensor, or switch, I'm referring to, is indeed attached to the throttle petal, under the dash, and comes as one complete assembly. I can't recall if it threw any codes, but the throttle became completely unresponsive, and the engine stalled when I tried to apply the throttle. I can't post a link yet, but if you'll google images... 
2004-2006 Nissan Altima Accelerator Pedal
There's a pic of the petal with the switch on it.


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## quadraria10 (Jul 6, 2010)

https://www.ebay.com/itm/Accelerato...-Maxima-Altima-APS190-/131440765083#vi-ilComp

Guess that is what you are talking about

But before that if he didn't do the proper learning procedures, this video shows how starting close to the 6 minute mark.


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## coreyzapf (Mar 4, 2018)

I went and changed the accelerator pedal and I did the relearn still nothing. I am stumped that none of these things fixed the issue


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## BlownSkillet (Mar 6, 2018)

Guess I'm out a paycheck! Makes absolutely no sense to me either. Changing the petal, with the same symptoms you're having, absolutely fixed the problem with mine, twice now.


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## quadraria10 (Jul 6, 2010)

I would try the relearn a few times. It can be tricky getting the timing exactly right. Use a watch second hand to be exact.

Maybe you have an air leak. Check around to see if everything is properly connected. Could the new throttle body be defective?


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## coreyzapf (Mar 4, 2018)

i have checked for all possible air leaks could not detect anything i have checked all harnesses to make sure they were properly connected everything seems to be connected properly. and the throttle body is new from 0riellys auto parts so I'm not sure what to do next. i kind of have to much money invested into it to just let it go, plus my credit kind of sucks really bad so no affordable loans for me lol.


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## rogoman (Dec 16, 2004)

coreyzapf said:


> so far I have tried a number of things but as my car reaches operating range it dies. In the last week here is a list of everything I have had to change on my 05 Nissan Altima 2.5 s
> 
> Throttle body
> MAF
> ...


While the engine is idling, if you gradually raise the RPM's, does it still shut off or does it continue to run? In other words, don't punch the RPMs up but very slowly raise it.

The condition you're describing can be caused by a marginal crankshaft position sensor or a camshaft position sensor. If you're buying one or both of them, buy only OEM units from a Nissan dealer. Don't buy aftermarket types; they've been known to fail in a short time; some are even DOA.

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The fuel pump may be operating, however the pressure may be extremely low causing your problem. The pressure needs to be tested as follows:
Tee-in a temporary fuel pressure gauge to the fuel rail input; you should use a "quick connect adapter". The reading at idle should be approximately 51 psi.

While you still have the temporary fuel pressure gauge installed, you can do a quick leak test; turn the ignition switch to the "RUN" position without starting the engine; make sure to pinch off the return hose on the pressure regulator when doing this. If the pressure drops off rapidly, one or more injectors are leaking.

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There may be a major intake system vacuum leak. Use a vacuum gauge for good accuracy; most auto parts stores sell vacuum gauges. To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source, usually somewhere on the intake manifold. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be around 21 InHg.

If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle body and at the MAF for cracks or loose clamps.


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## BlownSkillet (Mar 6, 2018)

Without reading through everything again, and at the risk of repeating something here, have you tried replacing the fuel filter? Cheap & easy. This is something else that gave me the same symptoms, just in a different car.


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## rogoman (Dec 16, 2004)

BlownSkillet said:


> Without reading through everything again, and at the risk of repeating something here, have you tried replacing the fuel filter? Cheap & easy. This is something else that gave me the same symptoms, just in a different car.


Unfortunately the fuel filter on his car is part of the fuel pump that located in the fuel tank; the filter by itself is not replaceable; the entire fuel pump needs to be replaced. Like I posted previously, it's best to first run a fuel pressure test to determine the condition of fuel delivery.


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## BlownSkillet (Mar 6, 2018)

I had no idea; I've been driving my wifes old 05 Altima for at least 3 years, and I kept telling myself "you need to change the fuel filter". Guess there's a lot I don't know about this car, since nothing ever goes wrong with it. A motor mount, an alternator,a few brake parts, and a couple of accelerator petals, are all I've had to replace in nearly 260,000 miles.


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