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I took my 2013 Maxima to Nissan of Elizabeth City for rough idle ! NOT FIXED ! They said it threw a code for misfiring in cylinder 3. Replaced coil , spark plug, fuel injector , and did compression test. All cylinders tested over 180 psi!
STILL HAVE ROUGH IDLE !! They said they DONT KNOW WHAT IS THE CAUSE !!! PLEASE HELP !!! Car is still financed !!!!!!!
 

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Calm down, there's no need to "shout". First, is it still throwing a #3 misfire code? Or is the code gone but the idle is still rough?
 

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Okay, first thing to check is your engine ground, since it takes 5 seconds. With the car running, put a voltmeter on the lowest scale and measure from the block to the negative battery post. It should read no more than 50 millivolts (0.05V). Maxes have a nasty habit of ground cable deterioration where it attaches to the tranny, and it can cause blown coils and a host of other symptoms. If the ground is good, inspect the mass airflow for lint, butterfly wings, or any other kind of junk. Nissans have no MAP sensor to double-check the MAF, so the ECM basically has to trust it. If it lies, bad things happen. Once it's clean, if they didn't do an IAVL (Idle Air Volume Learn) while you were in for service, get one done. I've seen MAF readings vary by as much as 30% on cars that went several years from the factory without an IAVL. It's just a matter of the silicon aging and it's harmless to the MAF, but if it's over- or under-reading because of old age, the ECM needs to know about it. That's what IAVL does, it re-matches the MAF to the ECM. Thirdly, depending on your driving habits, you could have a bad case of carbon buildup. If you drive like grandpa and don't "stomp it" very often, the back bank on VQ engines can get ugly carbon buildup on the piston crowns and intake valves. That's easy to fix, just warm it up fully, have an assistant hold the RPM's around 3500, and put a teaspoon of ATF (any kind works) down a vacuum port. The brake booster port is usually easiest. Any carbon in the engine will literally "crack loose" and go out the exhaust from the momentary temperature differential caused by the film of ATF. If it isn't any of those things, you should check for vacuum leaks. If you have a scanner that will stream either A/F-Alpha or Short Term Fuel Trim, you can confirm or eliminate a leak by watching the readings at idle and at 2500 RPM, if the readings go way rich at idle but normalize when you raise the RPM's, there's a leak somewhere.
 

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Discussion Starter #5
Okay, first thing to check is your engine ground, since it takes 5 seconds. With the car running, put a voltmeter on the lowest scale and measure from the block to the negative battery post. It should read no more than 50 millivolts (0.05V). Maxes have a nasty habit of ground cable deterioration where it attaches to the tranny, and it can cause blown coils and a host of other symptoms. If the ground is good, inspect the mass airflow for lint, butterfly wings, or any other kind of junk. Nissans have no MAP sensor to double-check the MAF, so the ECM basically has to trust it. If it lies, bad things happen. Once it's clean, if they didn't do an IAVL (Idle Air Volume Learn) while you were in for service, get one done. I've seen MAF readings vary by as much as 30% on cars that went several years from the factory without an IAVL. It's just a matter of the silicon aging and it's harmless to the MAF, but if it's over- or under-reading because of old age, the ECM needs to know about it. That's what IAVL does, it re-matches the MAF to the ECM. Thirdly, depending on your driving habits, you could have a bad case of carbon buildup. If you drive like grandpa and don't "stomp it" very often, the back bank on VQ engines can get ugly carbon buildup on the piston crowns and intake valves. That's easy to fix, just warm it up fully, have an assistant hold the RPM's around 3500, and put a teaspoon of ATF (any kind works) down a vacuum port. The brake booster port is usually easiest. Any carbon in the engine will literally "crack loose" and go out the exhaust from the momentary temperature differential caused by the film of ATF. If it isn't any of those things, you should check for vacuum leaks. If you have a scanner that will stream either A/F-Alpha or Short Term Fuel Trim, you can confirm or eliminate a leak by watching the readings at idle and at 2500 RPM, if the readings go way rich at idle but normalize when you raise the RPM's, there's a leak somewhere.
Thank You ! Will try !
 

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5mV is outstanding for the block ground, you shouldn't need to worry about the cable. For future reference, it attaches to the chassis just below the battery shelf and to the transmission housing behind the left front wheel.
 

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Discussion Starter #10
5mV is outstanding for the block ground, you shouldn't need to worry about the cable. For future reference, it attaches to the chassis just below the battery shelf and to the transmission housing behind the left front wheel.
What would you recommend to try next? I just drove her, and she runs pretty good, but at idle still a little rough.
 

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Have you checked the MAF for debris? That's next, and have someone run an IAVL on it. Doesn't need to be a dealer, most shops have a high-end scanner like a SnapOn Solus that will do the job.
 

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Have you checked the MAF for debris? That's next, and have someone run an IAVL on it. Doesn't need to be a dealer, most shops have a high-end scanner like a SnapOn Solus that will do the job.
Will be doing both this week, and will get back to you . Thank You for your HELP ! Really Appreciate it !
 

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I took my 2013 Maxima to Nissan of Elizabeth City for rough idle ! NOT FIXED ! They said it threw a code for misfiring in cylinder 3. Replaced coil , spark plug, fuel injector , and did compression test. All cylinders tested over 180 psi!
STILL HAVE ROUGH IDLE !! They said they DONT KNOW WHAT IS THE CAUSE !!! PLEASE HELP !!! Car is still financed !!!!!!!
I HAVE A 1996 infinity I 30 with 270000 miles on it. I did EVERYTHING, nothing worked. Thought it was the timing chain, Bought an engine from Japan. Still Does It. It seems like it is getting the wrong signal from the ECM with the low engine speed while in gear. There is a rotation sensor on the transmission that may not be working properly that gives a bad signal to the ECM. That is my latest theory.
 

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I HAVE A 1996 infinity I 30 with 270000 miles on it. I did EVERYTHING, nothing worked. Thought it was the timing chain, Bought an engine from Japan. Still Does It. It seems like it is getting the wrong signal from the ECM with the low engine speed while in gear. There is a rotation sensor on the transmission that may not be working properly that gives a bad signal to the ECM. That is my latest theory.
 

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Its most likely a mass air flow sensor problem. The ECU don't always detect code cause by the mag instead it focus on live event code. Misfire on coil and injector are also cause by maf sensor and not the coil or injector faulty components. The MAF sensor might be the cure.
 
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