fluctuating idle
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SidewaysSlider
- Posts: 6
- Joined: Tue Mar 15, 2005 4:01 pm
- Car: 1990 s13 coupe
fluctuating idle
hi all. ihave a problem with my sohc 240. at idle, the revs fluctuate from 500 to 1000rpm. Also, when my a/c is on... the revs fluctuate from 500 to 1000 when the compressor cycles on and off. and 1 more thing...wheni accelerate... the car hesitates for a second, then the power kicks in (in all gears). i have no idea what to do?? Any suggestions would be helpful. Thank for your time.
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1991S13
- Posts: 1230
- Joined: Fri Nov 19, 2004 5:59 pm
- Car: '91 240sx Coupe, '00 QX4 4x4, '02 Sentra Spec V
- Contact:
Since you're new I'll tell you first, click Search in the upper right corner and look up what your question is, most topics have been covered extensively.
But a lot of people have the idle problem. 500 to 1000 doesn't really sound that bad, mine holds idle at around 700. The black box on the driver side of the engine compartment, the AIV valve (has a rubber hose going to it from the airbox, and another hose coming from the header), can get clogged and send exhaust through your intake, causing poor idle. Take it out and pull it apart, and clean the reed in the inside. Or, you can just take the whole thing off, plug up the lines going to it (4 if Im not mistaken), and don't put it back on. It's for emissions, but after the car is warmed up it doesn't make a difference.
Clean your throttle body too. My car was idling at like 3,000 once, so I cleaned a lot of black junk off the throttle plate and it went back to normal.
Try that and see if it affects it at all.
But a lot of people have the idle problem. 500 to 1000 doesn't really sound that bad, mine holds idle at around 700. The black box on the driver side of the engine compartment, the AIV valve (has a rubber hose going to it from the airbox, and another hose coming from the header), can get clogged and send exhaust through your intake, causing poor idle. Take it out and pull it apart, and clean the reed in the inside. Or, you can just take the whole thing off, plug up the lines going to it (4 if Im not mistaken), and don't put it back on. It's for emissions, but after the car is warmed up it doesn't make a difference.
Clean your throttle body too. My car was idling at like 3,000 once, so I cleaned a lot of black junk off the throttle plate and it went back to normal.
Try that and see if it affects it at all.
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Dattebayo
- Posts: 33288
- Joined: Sun Aug 25, 2002 10:04 am
- Car: 2004 Nissan Frontier Desert Runner
- Location: NE DC
Unstable idle could be a million things.
EGR Valve, Cylinder misfire (a million things to check for with that too), oxygen sensor, Intake vacuum leak, Idle adjustment screw low or clogged, compression bad, or finally a bad computer.
You see, there is a procedure in the factory service manual that covers the whole thing (procedure number 3). Go download it.
EGR Valve, Cylinder misfire (a million things to check for with that too), oxygen sensor, Intake vacuum leak, Idle adjustment screw low or clogged, compression bad, or finally a bad computer.
You see, there is a procedure in the factory service manual that covers the whole thing (procedure number 3). Go download it.
