some help please

[Lenneo]

i have a 96 q and a bit of a problem, any suggestions would be greatly appreciated. My car runs perfectly for about 15 mins when i first take it out. Then after 15 mins, it begins to accelerate slower and shakes and jerks when i stop at a red light or stop sign. I cleaned the MAF, but that didnt help. I dont know if the rpm gauge has anything to do with the problem, but it also does not function properly. It is either always at zero or is erratically jumping up and down. Any suggestions guys??

[ILuvNkdChx]

How many miles? Do you know the service history? Check engine light on? The 96 was the first year for OBD II so you could just go to any local automotive store and have your codes checked.

[Lenneo]

it has 114k, and the check engine light is sometimes on and sometimes not. I checked the codes and the only thing that came up was the knock sensor, which would not be a cause of my problem. I recently changed the TPS, and i know that the car hasnt gotten a tune up in a while....

[ILuvNkdChx]

There are people on here that know 654,348,392 times more about this car than me, however, I would R & R the knock sensor(s), check all hoses while you are in there. Ohm test your injectors while your plenum is off. R & R old plugs (w/NGK's) and R & R any filters you are unsure of. If you do not have, but would like the service history of the car, the information can be obtained from one of your local Infiniti dealers with your VIN #.

[maxnix]

Probably needs a lot more than a "tune up".

When did you last cahnge all of your fluids and filters? Fuel pump? Ohm your injectors? Correct plugs?