when even im just driving the the street and i put the tranny into neutral and just start coasting, my idle will be too high. it will drop to the normal 650, but then instantly shoot up to 1000 and stay there until the car comes to a complete stop. as long as the car in in motion, it wont idle at its normal 650.

i had this problem a couple of months ago. when i replaced my PCV valve it went away, but now its back. is my PCV valve just sticking again or is it something else?

 

this is normal actually I think....if I understand your symptoms right, mine does this as well...I think it has something to do with the IACV....dunno fer sher though....when crusing and moving, my idle won't drop to 650 unless it's at a stop...and I have a brand new nissan PCV, fuel filter, air filter, spark plugs, knock sensor...(you get the picture)

I think there is a purpose to why our cars do that...

 

This is normal for the Maxima. To protect the engine when still moving it won't drop. Only on stop it drops to around 700.

 

hmm, but if its normal then why did it stop doing that? like 6 months back it always did it, then i did a tune up. changed all the fluids and cleaned all the valves and it stopped, now a couple months later, it does it again. can anyone else confirm that this is a normal thing?

 

Your throttle position sensor may be malfunctioning. Look at this link to see if these symptoms fit. From what I understand, your TPS may be going bad, but it won't throw a code until it's completely done. http://vbxmaxima.8m.com/tps.html

 

mine goes back to regular idle speed, but then again my tps may be acting up too.

but none the less mine goes to idle speed if I hit neutral but still traveling at decent speed. will check later on the drive home after class

 

i dont think its a TPS problem because my idle never goes below 650.

 

I really do think this is normal...probably reduces emmissions or keeps the fuel pressure up while coasting or maybe even keeps the alternator amps up when coasting so if you coast for a long time all your accessories and such continue to have good power

anyone of those could be a reason for nissan setting up our cars to do this....every stick shift maxima I have ever been in has done this....including mine....and my IACV is as clean as can be and my TPS specs perfectly on my multimeter...

more of a mystery is why when at a stop and at idle, I can watch my tach needle real closely and watch it fluctuate every so slightly up and down up and down...you wouldn't notice it unless you put your face up against the steering wheel pretty much, but nonetheless it does it....it did it before my UDP....and after, and even with a grounding kit...still does it...I am thinking coil packs are trippin out a bit....they are the originals....

 

I think its normal too. My '95 will drop to 1000rpm for a few seconds and then drop down to 700rpm. If I put in the clutch and just coast, it will drop to 700rpm after a few seconds even if I haven't stopped moving. I'm sure if you are on the freeway and put the clutch in, the idle will drop to normal idle after a few seconds. It has nothing to do with the car in motion, you just obsverve it this way because you have only noticed the issue when you put the clutch in as you are rolling up to a stop sign or traffic light. I originally thought the same thing.

I think it has to do either (or both) with emissions and the fact that its easier to shift gears with a stick if the idle doesn't drop real low as soon as you depress the clutch.

Greg