1993 Other Infiniti Models My car runs rough between 2300 to

1993 INFINITI
194,000 MILES • 6 CYL • 2WD • AUTOMATIC
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H_HARDING
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I have an old Infiniti J30 with about 194000 miles on it. As old as it is, I love the car but the old girl is sick right now. With the car in drive and moving If I accelerate up to 2300 rpm, I loose all power with little or no throttle response, and the car starts jerking. When I stop and place the car in neutral I rev up the engine and at around 2300 the engine begins to run rough as I increase rpm beyond 2500 the engine once again revs up smoothly with good throttle response.
The transmission shifts normally with no issues that I can tell. At this point I think it may be the timing belt but I'm really not sure. Can you offer any suggestions for me?
Jul 15, 2008 at 4:07 PM
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KHLOW2008
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Hi h_harding,

Is the check engine light showing?

I would suspect the EGR or throttle position sensor is giving the problem.
Jul 16, 2008 at 11:08 AM
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H_HARDING
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Hi and thank you. No the check engine light is not on but I never thought about the throttle position sensor, thank you.

Can you tell me what the throttle position sensor does?
Jul 16, 2008 at 6:02 PM
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KHLOW2008
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Hi h_harding,

The function of the TPS is to inform the ECM of the throttle opening, ie. how much you have depress the accelerator.

This coupled with the engine rpm, vehicle speed, air flow, engine temp etc would tell the ECM what needs to be done.
Jul 17, 2008 at 9:04 AM
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H_HARDING
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Thank you to all that responded.

God Bless.
Jul 17, 2008 at 7:23 PM
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H_HARDING
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One last question. Where is the throttle position sensor physically located? I know where the ECM is but I'm not sure where the TPS is located.

Thank you.
Jul 18, 2008 at 8:12 PM
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KHLOW2008
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Hi h_harding,

You are always welcomed to come back with more questions.

The TPs is located on the throttle body and is installed opposite the throttle cable. If its is a fly by wire, then it is located next to the accelerator pedal.
Jul 19, 2008 at 11:14 AM