1994 Infiniti Q45 Acceleration issues

1994 INFINITI Q45
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MEKHONGJUNKIE
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Engine Mechanical problem
1994 Infiniti Q45 V8 Automatic 139000 miles

I've had my Infiniti Q45 for about a year, it's a 94' with almost 140k miles. About two months ago the car started with acceleration problems... jumpy rpm's, stagger, boggle and wouldn't allow me to get above 40mph unless I completely backed off the throttle, then it seemed to catch. The engine light comes on and off randomly, usually in city, but recently highway also. When this acceleration issue occurs I tried flooring it to see what would happen and the rpm's nor the speed would respond and I almost could hear a "popping" like sound from under the hood as if it's trying to force a boost while the rpm's jolt. A mechanic told me two weeks ago my Mass Air Flow Sensor was bad, I replaced it, and the car accelerated better, but lacked power and performance. I still get engine lights on and off, and today I almost didn't make it home from school. I made a turn off a road and when I went to accelerate the car wouldn't go past 20mph, it seemed that if I backed off the throttle it would move a little, but if I gave it gas it only slowed. I had to pull over and avoid cars to get it home at 20mph. Also, the rpm's run high if i'm in neutral, and i noticed when in idle a while it sounds as if it may die, with the rpm needle fluctuating up and down. Please help!
Jan 28, 2009 at 7:32 PM
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RASMATAZ
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Get the throttle position sensor and the exhaust system check for restriction and fuel pressure
Jan 29, 2009 at 2:30 AM