bucking and jerking

[troyb17]

I have a question i wondering if your fuel pump can cause jerking,bucking,and deaccelerating on your vehicle when going up on hills.I replace the mass air flow and the jerking and bucking went down a little bit but not much.I also notice that it sounds like its backfiring from the front when i push the gas pedal down likes its getting no power.I know i hear like a humming noise from the trunk so i assume thats the fuel pump.Also does the TPS has something to do with the bucking and deacceleration also.Im just trying to figure whats going on cause Im not trying to spend money uopn money on parts when thats not the problem.

[Jeff Williams]

The first step is to get the codes from the ECU.

Make sure the air filter is clean, the throttle body is clean, and the MAF contacts are clean and are making good contact. There are a lot of things that could be causing the problems you are mentioning.

Also, read some of the previous threads on the Q45 in the "INFINITI Online Mechanic" forum.

The fuel pump definitely needs to be replaced, so do it first. Replace the fuel filter at the same time.

When were the plugs replaced? Are they NGK, because if the yare not, go ahead and replace them again.

Is the transmission fluid at the correct level? Has it been flushed recently?

Have the fuel injectors been cleaned or replaced? Have you ohmed them out? Has a fuel rail flush been done recently? What kind of fuel are you running?

What is the history of the car? Have you owned it since new? Did you just buy it? Do you have any service history?

Can you afford to have a local dealership run a Consult diagnositc on the car? It might run $150 to $200 just to find out what is wrong.

[goody90q45]

Follow all of Jeff's advice. Pull the codes from the ECU first. It's very simple to pull the codes and it sounds like there may be a few there waiting for you. Search for ECU and you'll find what you need.

Also get an FSM (Factory Service Manual) if you plan on doing any work yourself. To really understand what's wrong with your car stay where you're at right now and start reading posts. Between this board (Q45 Forum) and Infiniti Online Mechanic there is everything you need to know. Spend days, not hours, reading everything you come across.

If you do only some (or none) of the above you'll go broke taking your car to repair shops to keep it in tip top condition.

[elwesso]

Do the easy stuff like Jeff said, and get your fuel pump from Joe, his contact information isin my sig. below this post.

[Jesda]

Get on top of the car and see how long you can stay on!

Probably MAF.

[troyb17]

i changed the MAF but there is still jerking and bucking