2000 Nissan Maxima Idle Problem
2000 Nissan Maxima Idle Problem
Hello, i have 2000 Maxima, from last month or so when my car is idle its rpm race up to 1500 and when i put it into D goes back to 1000rpm. but since last week it drastically goes up and down from 2000-1500 rpm contantly when in N. and also while driving i notice it maintain 2000 rpm without foot on speed. please help send suggestion on [email protected] thanks in advance
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Re: 2000 Nissan Maxima Idle Problem
"makhbk," this is a car club so responses are for everyone to read and learn.
Is the CEL on? Regardless, have an OBD scan from Autozone and the likes for any trouble code or ECU communication problem. A trouble code can help us isolate the problem.
The problem may be as simple as leak in the air intake to worst, a 'fried' ECU. So do the simple things first. Check for any leak in the air intake. Use a carb cleaner and spray around the intake tube, especially at the fittings. A change/surge in RPM indicates a leak that has to be fixed. If the intake is Ok, check the condition of the throttle cables (main and cruise control). Maybe they are 'sticky' and needs lubrication. Also possible that one of the cables is tight and dragging the other, causing high RPM.
As to the possibility of a fried ECU, it can be due to a shorted IACV stepper motor and, if applicable, electronic engine mount. If you have electronic engine mount and you hear buzzing, especially after you shut down the engine, the electronic engine mount is on the way out and could be shorted. Unfortunately, the drivers (power transistors) for the IACV stepper motor and electronic engine mounts are inside the ECU. So if either one is shorted, the power transistor will overheat and 'kill' the ECU. So if you have electronic engine mount, disconnect the connectors and check the engine response. You may not even feel the difference with the electronic engine mount disconnected.
If the problem persisted, it could be due to bad IACV (dirty or shorted), faulty TPS (Thottle Position Sensor), dirty TB (throttle Body and butterfly valve), dirty/erratic MAF (Mass Air Flow) sensor or even a Coolant Temp Sensor. You now have remove the air intake and replace the Air Filter if dirty. Clean the MAF sensor (with Zero-residue Contact Cleaner or CRC MAF Sensor Cleaner) and connector, clean the TB with carb Cleaner (use rag, do not spray directly into the assembly as the cleaner could seep into the TB sensors). Remove the IACV and check the condition of the gasket (bad gasket can cause water migration); check the resistance of the stepper motor, 20-30 ohms; clean the assembly if resistance is good. You may have to use a new gasket on installation.
There are other things that you can do like IAVL (Idle Air Volume Learning) and requisite steps.
If the ECU is fried, you are out of luck. You can buy new or refurbished one but regardless, you need programming from the dealer as the car will not start (NATS, Nissan Anti theft System 'kicks in' to immobilize your car since the Ignition Key ID no longer matches with that in the new ECU).
Is the CEL on? Regardless, have an OBD scan from Autozone and the likes for any trouble code or ECU communication problem. A trouble code can help us isolate the problem.
The problem may be as simple as leak in the air intake to worst, a 'fried' ECU. So do the simple things first. Check for any leak in the air intake. Use a carb cleaner and spray around the intake tube, especially at the fittings. A change/surge in RPM indicates a leak that has to be fixed. If the intake is Ok, check the condition of the throttle cables (main and cruise control). Maybe they are 'sticky' and needs lubrication. Also possible that one of the cables is tight and dragging the other, causing high RPM.
As to the possibility of a fried ECU, it can be due to a shorted IACV stepper motor and, if applicable, electronic engine mount. If you have electronic engine mount and you hear buzzing, especially after you shut down the engine, the electronic engine mount is on the way out and could be shorted. Unfortunately, the drivers (power transistors) for the IACV stepper motor and electronic engine mounts are inside the ECU. So if either one is shorted, the power transistor will overheat and 'kill' the ECU. So if you have electronic engine mount, disconnect the connectors and check the engine response. You may not even feel the difference with the electronic engine mount disconnected.
If the problem persisted, it could be due to bad IACV (dirty or shorted), faulty TPS (Thottle Position Sensor), dirty TB (throttle Body and butterfly valve), dirty/erratic MAF (Mass Air Flow) sensor or even a Coolant Temp Sensor. You now have remove the air intake and replace the Air Filter if dirty. Clean the MAF sensor (with Zero-residue Contact Cleaner or CRC MAF Sensor Cleaner) and connector, clean the TB with carb Cleaner (use rag, do not spray directly into the assembly as the cleaner could seep into the TB sensors). Remove the IACV and check the condition of the gasket (bad gasket can cause water migration); check the resistance of the stepper motor, 20-30 ohms; clean the assembly if resistance is good. You may have to use a new gasket on installation.
There are other things that you can do like IAVL (Idle Air Volume Learning) and requisite steps.
If the ECU is fried, you are out of luck. You can buy new or refurbished one but regardless, you need programming from the dealer as the car will not start (NATS, Nissan Anti theft System 'kicks in' to immobilize your car since the Ignition Key ID no longer matches with that in the new ECU).