Idle drop
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Joined: Dec 2006
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Idle drop
I am having an issue that has been going on now for over a year.
After driving for short (or long) distances and I get up to modest speed (anything above 40+mph) - when I come to a stop and idle the car will idle ~700-800rpms as is normal. However after sitting idle for a short while (ranges from 15 seconds to 1 minute at idle), the idle will drop to ~400-500rpms (almost die) for a second or two and then climb back to ~700-800rpms.
It will do this with and without the A/C on. It does it both while in drive and in neutral. I have changed air filters, cleaned the mass airflow sensors but it is still doing it. What's weird is, it has not seemed to get any worse over the last year. I would think if it was a fuel issue or sensor issue - it would get worse over time.
I run fuel additives about once every four to six months. Could this just be a dirty throttle body? Should I try adding some more? Thoughts? Thanks in advance.
-Jason
After driving for short (or long) distances and I get up to modest speed (anything above 40+mph) - when I come to a stop and idle the car will idle ~700-800rpms as is normal. However after sitting idle for a short while (ranges from 15 seconds to 1 minute at idle), the idle will drop to ~400-500rpms (almost die) for a second or two and then climb back to ~700-800rpms.
It will do this with and without the A/C on. It does it both while in drive and in neutral. I have changed air filters, cleaned the mass airflow sensors but it is still doing it. What's weird is, it has not seemed to get any worse over the last year. I would think if it was a fuel issue or sensor issue - it would get worse over time.
I run fuel additives about once every four to six months. Could this just be a dirty throttle body? Should I try adding some more? Thoughts? Thanks in advance.
-Jason
Last edited by jasplat88; Feb 10, 2012 at 10:22 PM.
It is in fact just dirty TB and is very common on our cars even on low mileages, just read and follow the DIY but be warned that while some people have had no issues with the TB reset after cleaning some have had a horrid time with it requiring them to spend hours trying to properly folow the procedure to the t and successfully reset the TB
There's also this latest TSB that just came out for somewhat related symptoms (although you engine doesn't stall completely); just thought it might be something to consider.
http://x.infinitihelp.com/forum/loca...p=12&keyid=290
http://x.infinitihelp.com/forum/loca...p=12&keyid=290
Registered User
Joined: Feb 2007
Posts: 284
Likes: 3
From: Atlanta, GA
2008 G35 Journey Sedan no sunroof
I have the exact same problem (08 G, 40K miles) and have asked dealer to check it twice -- with the hope of getting throttle body cleaned for free -- but both times they reset the base idle and said "no problem found".
So should I just ask for a throttle body cleaning and expect to pay out of pocket? (I felt comfortable doing it myself on my '92 Q45, but I'll leave this one to the pros) I asked the independent shop I used for my Q45 about this and they said even they don't touch the drive-by-wire cars.
If the dealer cleans the throttle body is it strictly a manual process (i.e. cleaner and toothbrush)? Or do they use a vaporized cleaning solution which cleans the entire intake plenum? (I had this done several times on the Q45 and it was awesome afterwards... but this was after 150K+ miles)
In addition to the idle dropping below 600 in D (usually at stoplights) the idle will also drop right after starting the engine when it's warm. It starts up at around 1200 rpm then drops below 600 then immediately recovers -- but the brief shudder when it drops is irritating.
So should I just ask for a throttle body cleaning and expect to pay out of pocket? (I felt comfortable doing it myself on my '92 Q45, but I'll leave this one to the pros) I asked the independent shop I used for my Q45 about this and they said even they don't touch the drive-by-wire cars.
If the dealer cleans the throttle body is it strictly a manual process (i.e. cleaner and toothbrush)? Or do they use a vaporized cleaning solution which cleans the entire intake plenum? (I had this done several times on the Q45 and it was awesome afterwards... but this was after 150K+ miles)
In addition to the idle dropping below 600 in D (usually at stoplights) the idle will also drop right after starting the engine when it's warm. It starts up at around 1200 rpm then drops below 600 then immediately recovers -- but the brief shudder when it drops is irritating.
Registered User
Joined: Sep 2010
Posts: 352
Likes: 29
From: Huntsville, AL
Mine does this too. I got everything to clean the TBs, but decided against it after reading about the issues some people were having. I don't want to pay for someone to do something I can do myself, but at the same time I don't want to mess anything up either.
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I had also same issue. Bring the car to dealer and throttle plate got cleaned under the warranty. ( I was told they cleaned throttle plate - I am not sure if this implies throttle body altogether)
Anyway, idle problem is gone.
Anyway, idle problem is gone.
Registered User
Joined: Feb 2007
Posts: 284
Likes: 3
From: Atlanta, GA
2008 G35 Journey Sedan no sunroof
I have the exact same problem (08 G, 40K miles) and have asked dealer to check it twice -- with the hope of getting throttle body cleaned for free -- but both times they reset the base idle and said "no problem found".
So should I just ask for a throttle body cleaning and expect to pay out of pocket? (I felt comfortable doing it myself on my '92 Q45, but I'll leave this one to the pros) I asked the independent shop I used for my Q45 about this and they said even they don't touch the drive-by-wire cars.
If the dealer cleans the throttle body is it strictly a manual process (i.e. cleaner and toothbrush)? Or do they use a vaporized cleaning solution which cleans the entire intake plenum? (I had this done several times on the Q45 and it was awesome afterwards... but this was after 150K+ miles)
In addition to the idle dropping below 600 in D (usually at stoplights) the idle will also drop right after starting the engine when it's warm. It starts up at around 1200 rpm then drops below 600 then immediately recovers -- but the brief shudder when it drops is irritating.
So should I just ask for a throttle body cleaning and expect to pay out of pocket? (I felt comfortable doing it myself on my '92 Q45, but I'll leave this one to the pros) I asked the independent shop I used for my Q45 about this and they said even they don't touch the drive-by-wire cars.
If the dealer cleans the throttle body is it strictly a manual process (i.e. cleaner and toothbrush)? Or do they use a vaporized cleaning solution which cleans the entire intake plenum? (I had this done several times on the Q45 and it was awesome afterwards... but this was after 150K+ miles)
In addition to the idle dropping below 600 in D (usually at stoplights) the idle will also drop right after starting the engine when it's warm. It starts up at around 1200 rpm then drops below 600 then immediately recovers -- but the brief shudder when it drops is irritating.
Good news. Took it to dealer (Nalley Infiniti Decatur, GA) and service advisor (Jeff) offered to do induction cleaning (injectors and intake) for $140. I told him that was fine "if it will fix the problem for sure." Dealer tech drove the car long enough to verify the problem this time, found ITB for the problem (same as TSB?), cleaned the throttle bodies and and updated ECM program. No charge (covered under warranty).
That's not good. How are they accurately keeping track of what service has been performed on your car then? 
Last edited by vqsmile; Mar 30, 2012 at 06:22 PM. Reason: sp
