Engine Performance problem
2003 Nissan Altima 4 cyl Front Wheel Drive Automatic 80000 miles
03 Altima 2.5 L. Car idles perfectly without load. When car it put in rev or drive - the motor vibrates like it isn't getting enough fuel & has very little pulling power. Its been to 5 mechanics and a transmission shop. The car is not giving any codes at all. All mechanics including the dealership says they cant find anything wrong. You can hold the brake in drive and floor the gas and it will not go over 1000 rpm? But you can take it out of drive and it will redline. I thought the torque converter had a problem but the shop said it was not a transmission problem - that it had something to do with engine performance instead. It has good compression and plenty of power after you get out of the lower gears. Plugs are new - fuel pressure is good. Ive removed the precat to prevent it from coming apart and damaging the motor. There is no vacuum or intake leaks. All that is left are sensors. It sounds like it could be the MAF (I have cleaned it several times and no change - you can unplug it and it really runs rough) Some have told me to replace the throttle body because it sounds like the throttle position sensor isnt working properly. Is there any way I can check this? Any suggestions would be appreciated. I know there is the speed sensor, Crank sensor, cam sensor, MAF & Throttle body I just don't know where to start?
have the same problem?
Thursday, June 11th, 2009 AT 9:39 AM