After I accelerate hard and approach a stoplight I drop it into neutral and rpms bounce up and down couple times then hover around 1200rpms and drop to normal. This only happens sometimes any Ideas?

 

I'm gonna go with a good cleaning of the iacv and throttle body..Be sure to get throttle body cleaner,not carb cleaner..You will need a new gasket for the iacv unit,so be sure to pick one up before you take it apart.

Also,get a couple cans while your at it,I tend to run out with one can before i'm done cleaning..

 

Might be a bubble in the cooling system, the maxima's system is very hard to get perfect.

It also might be because the auto ecu and its fuel/timing map. My friend that converted his 240sx to a manual had a similar issue, and had the stock ecu flashed to a manual ecu map. You can get a VG-5 ECU or get yours flashed.

~Alex

 

+1 on IACV as most likely.

Not a-frigging-gain!.

I recently tried to explain, in another thread where you posted the same idea, that a "bubble" in the cooling system cannot possibly affect the idling speed at the rate you seem to think it can.

Once again - can I ask you to explain the mechanism you envisage by which this can be made to happen when the casting the ECU temp sensor is located in as well as the temp sensor itself has a thermal characteristic only able to respond in the order of 10s of seconds to temp changes experienced on the average motor.

 

I cleaned it not to long ago but it cant hurt to clean it again. I have another gasket for the tb layin around so I could do that anytime. Ill post up if that fixes it.

 

mine kinda does the same thing......it's very random, and not associated with any particular action. I will be driving at 3000rpm (example)...and it will jump to 6k or 7k and move in that range as if i were actually there...then it will kick back down to normal, all the while the engine is running normally. and sometimes it will just jerk up a few times then back to normal.

 

well mine isnt that EXTREME but it does bounce around a little it acts like it wants to stall.

 

So you have a stuffed rev counter - thats all.

 

is it anything like my problem??

http://forums.maxima.org/showthread.php?t=529041

 

i have no stalling or anything, just a wacky tach....stuffed? elaborate?

 

Fix it? .........................

To be more specific one would have to sit with the animal on a bench on front oneself ................. I don't because you have it there.

So if the wiring to the dash is OK I would guess replacement with a known working unit is the only way to confirm the cause.

If there is somebody here with detail knowledge of failed rev counters hopefully they will take the time to post their experience and help you here.

 

lol yeah, it's not a big deal right now, i'll probably check wiring and do a controlled swap if the wiring is good....but not yet.

sit with the animal on a bench on front oneself eh? hmm....no clue what you just said.

 

a sensor isn't happy with something about you coasting in neutral after pushing so much air in/out. the early nineties honda accords do this all of the time in neutral, after several years of use. its never been known to be a problem, just annoying.