Acceleration Issue

[londonontman]

I apologize if this is the wrong area to post my question. Its my first time posting here. I have a 2000 Maxima GLE. When I move the accelerator pedal to the floor quickly the car reacts with no forward acceleration...almost like it is fuel starved. When I slowly move the pedal down everything the car is slow to accelerate. I have heard the the TPS could be an issue and is adjustable. Have also heard that the MAF sensor might be going to. Any ideas or am I way off track with my thinking...

[Eikon]

is your check engine light on? Typically a performance issue that severe will trigger some sort of ECU code which will point you to the problem.

TPS could certainly be an issue.

[NutriaforBreakfast]

The throttle position sensor might be the problem or it might not. In the FSM,
it is listed as an item to check for transmission shifting probems.

There are other items to check in the troubleshooting flowchart first like
low transmission fluid.

[londonontman]

When I press the pedal to the floor the car almost has the hic cups. Its like it thinks about accelerating...then sputters with some small reving...then rpms go from 500-2000 (needle goes flying up and down). Its very hard to describe here in all honesty

[londonontman]

Oh..and the transmission fluid is full......Whats an FSM?

[goody90q45]

is your check engine light on?......

To the OP....this is a pretty important question to answer. If the check engine light (CEL) is on then the ECU codes need to be read to help us help you with the diagnosis.

If the CEL is not lit you probably have an issue with fuel delivery- plugged fuel filter, a dying fuel pump or a problem with the fuel pump control unit (FPCU). If this is the case you'll need to check fuel pressure by teeing into the fuel inlet line somewhere between the filter and the injector rail.

Oh..and the transmission fluid is full......Whats an FSM?

Factory Service Manual. Fuel pump diagnosis is in the EC (emissions) section, not the fuel section.

http://www.nicoclub.com/FSM/maxima/2001/

[londonontman]

Sorry...didnt read all the way through. No the CEL is not on. I was lead to believe that the fuel filter was non serviceable...inside the tank?.

[goody90q45]

Oops. The location of the filter may be different than my Q45 but the fact that the CEL is not on has to lead you to check fuel pressure first. I'm not familar with the Maxi engine layout but there should be somewhere close to the fuel rail to tee in to check fuel pressure.

[loystock]

The TPS, MAF and even the VSS, etc., may be the problem but start with simple/cheap ones and go from there.

Have an OBD II scan from Autozone and the likes. The CEL may be off but you may have ghost codes stored in the ECU. A faulty KS sensor (P0325) will store a fault code but will NOT turn on the CEL, yet will impact your acceleration (and power due to ignition retard).

Check the entire air intake - check/replace the air filter; clean the MAF sensor and connector (CRC MAF Sensor Cleaner will do. Apply dielectric grease on the MAF sensor connector); clean the Throttle Body (do not spray carb cleaner directly in to the TB...use a rug); check for any air intake or vacuum leaks. Also clean/replace the PCV valve. Please note a dirty or failing MAF sensor may not necessarily throw a fault code

You may have a slack on the throttle cable. Make sure the throttle valve is fully responsive to accelerator pedal operation (2nd person needed to do this).

You may have a stuck e/parking brake. Ensure the parking brake is released, jack up the rear wheels and see if they spin freely.

If all of the above are Ok, then you need to check the fuel pressure - 34 PSI with engine running (vacuum on) and 43 PSI with Ignition ON but engine OFF, limited to 5 seconds. Also, one of your cylinders may be bad.

[londonontman]

I have access to a Snap On Modis system so when I head to my garage tomorrow I will check all of this out. Thanks for the info.