engine rpm drop at idle?
 

While sitting in neutral and when I rev the engine, as the rpm drops it drops below idle and goes back up to normal idle rpm. When it hits it lowest rpm it sounds like the valves are banging on the cylinders. I know others had this problem before but what can I do to fix this? It doesn't happen all the time. I also made a video that I will upload when I get home.

Sub'd

Have this problem too, Cell by any chance when that hapoens does your Batterry Gauge seem to drop aswell???

Is this a stock tune or Uprev?

I get this, too, and I can hear the fuel pump motor sag.

updated post with video.

Don't know.

stock. does uprev fix it?

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My does something similar but when I'm driving and come to a stop, the rpms drop and I can feel the car almost like shudder.

Anyone with uprev and tuned have this problem?

I've got the UpRev tune, but I don't remember revving it seeing it drop like that since it's something I hardly do. However, if I let my car idle for several minutes or warm up there are times idle drops momentarily.

Mine has Uprev and my idle is steady + or - 15 rpm

wow, never seen my rpm drop that low

If you're still under warranty, let the dealer worry about it.

I'm no expert but if this was happening to me I'd try a few things that are easy to check and/or fix.
Dirty air filters. Real easy to check and change if needed. Instructions in Owner's Manual.
Dirty MAFs. Easy to check/clean if you have a few common tools. Spray cleaner is available at most auto parts stores.
O2 sensors. Easy to check if you have an OBD/CAN scanner.
Vacuum leaks. Check all the hoses and fitting on the engine.

An OBD/CAN scanner will also allow you to check other engine variables that might be related to the problem. Good investment if you plan on doing any troubleshooting or mods.

Maybe someone who is an expert will chime in soon.

Car has 2400 miles on it and the only mod is a catback exhaust. I think it might be the stock tune.

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This is what i meant , didnt know how else to put it lol :icon18:

Mine has done it twice, took it to the dealer and they found nothing. my 07 g35 did the same thing alot, dealer finally diagnosed and after 2500.00 fix under warrany thank goodness. traded it in after that, gotta find my invoice to tell you exactly what it was. nissan wants me to bring it to them tomorrow...they think I'm making it up:shakes head:shakes head:

I hope it is a simple thing like a dirty throttle body or just a bad stock tune.

I would assume either one of those would fix it.

The thing is, I only have 24XX miles on my car. I doubt the throttle body is dirty.

I'm over 53k, so I think a good clean is in store especially after over 33k of turbo goodness.

For those with CAI or turbos who has done this, is there much effort in removing the intake pipe without having to take a bunch of stuff apart? I'm lazy lol, so I wonder if there's some leeway in moving it out to make room to remove the TBs to clean them.

Anyone that subbed this. THe answer to fixing this problem is a retune.

After doing my BP kit and loading the base tune, the idle drop is gone.

i made a thread about this. it only happens to me when my AC is on. others on the forum believe its the AC recirculating or something along those lines.

I have found it is the tune, the tuner needs to look at the fuel at idle and make sure the fuel/MAF is dialed in properly. Spent 2 years driving with a bad idle/drop issue and a retune fixed, changed nothing else.

Not only do I get that drop at idle, but as of late it's gotten a little chilly here in VA and now my idle is high at 1k. It's normally around 700. I'm almost positive it's because of the stillen intakes because I also have a check engine light. And for me check engine light goes hand and hand with cold weather. Is the high idle just the car trying to compensate?

had this. just had to clean the throttle bodies. the idle drop was accompanied with a battery voltage drop too.

Oh I'm just starting to remember this idle drop. I can hear power to the fuel pump sag as well.