When i turn on the car and when its cold after 1 minute the rpms jump up and down when warm it slows down how come i have no clue on this though any help thank you.

TopSpeed

 

Bump! Super Bump!

 

When its cold the engine idles around 1k RPM to warm up, this is normal.

 

Its normal its trying to warm it self up.

 

but it makes noise back and forth and not idle type is that fine or something needs to be done thanks.

TopSpeed

 

it sounds pretty nromal. if it jumps around a lot you may need to clean your tb, but it sounds right to me. it jumps around after a little bit because the computer is trying to keep the f/a mix right and when you even just touch the gas it messes it up, making the rpms fluctuate.

 

Hooper Whats TB?

 

should i just post a video clip lol

 

TB = throttle body.

 

If you think it sounds like something is wrong, posting a video couldnt hurt

 

i will post tomorrow oh so show you a clip and you let me know guys thanks.
TopSpeed

 

I have this same problem, most people just keep telilng me that it is just warming up but I know what my car 'sounded' like warming up. Last couple of days its gotten much louder and the idle has increased to about 2K and its very jumpy, 2k - 2.3k in very fast intervals, so it sounds like as if I was steppin on the pedal rapidly to rev the engine, which off course I'm not doing. Then when I put the car in gear and let go off the brake, it shoots off much quicker as if I was applying gas to the pedal, [which I'm not doing]

 

could possibly be an 02?

 

Well I"m trying to narrow it down to either IACV, MAF, or o2 which I think is th eleast likeley. This morning after garaging the car I went to turn it on, started up just fine but its now ideling at 1.5+ but its not jumping up and down at least, the "airbox" sound is very loud

 

Update: I went to autozone and pulled the P0505 IACV code. Is there even any use in trying to clean this thing or anything else rathern than just dropping the $200+ ....bc I have a feeling that with this the MAF is gonna go bad right after it lol. Also would I need a new reprogram?

 

Clean the TB, Maf, and the Air Temp. Sensor.

 

Update: Unfortunantley it turned out to be a little more serious in my case. I tried cleaning everything but to no avail. Then I finaly checked the IACV and it seemed that it got stock open and caused a short-circuit on the computer [the control one underneath the steering wheel, not sure of proper name]. I called the dealership and they wanted $700 for a new one which I was not having, I ended up finding a junk-yard that had no idea what that little grey box did so I ripped it out for $140 with tax and all, and bought a brand new IACV and replaced it all, got a free re-program and now its back to normal finaly,

I'm still dissapoined as my max only has 45k on it!!

 

TopSpeed says it's not just normal warming up where the needle makes slight little jolts. He's making it seem more violent than that -- in which case it's definitely the Idle Air Control Valve going bye-bye.

 

Whatever happened to the video?

 

i was trying to get the video but i started the car again and it went fine so, i couldnt show nothing. Strange to say I believe its my box for the intake, i have stock box but, when i bought the car, the person had a intake, so i believe that could be the problem. I will try to talk to my friend tomorrow about this he owns a shop once i install my shocks maybe he can fix this ill keep this posted sorry guys for the delay.

TopSpeed

 

i dont know who diagnosed your car, no disrespect if it was yourself, but that sounds like a big load of crap. if the iacv did get stuck, and did cause a shot, it would likely just blow a fuse and nothing more, no way it would just fry the ecu. if anything the iacv was just dirty (common problem) with just a cleaning of the sensor and housing the problem should have been fixed. also maybe change the fuse. if the ecu whold have been blown im not sure the car would drive at all.

 

Well the IACV did get stuck for sure, now the sketchy part comes with the blown ECU part. I'm pretty sure it has its own fuse somewhere and that it would have protected it from blowing. When I got to the shop to see the fried ecu i had noticed that they had been doing some voltage testing and maybe sent full 12volts from the battery and fried the ecu, because I inspected the ECU and only one of the chips on it was fried. When I asked a Maxima tech at another shop if there is a special chip for the IACV he said yes but not common that it would fry out although it has happened in the past. Whatever the hell happened I ended up having to buy a new ECU from the junkyard for $140, however if you're saying that theres no way it could have been blown while I was driving my car then I will raise hell.

It seemed quiet odd that I would have been able to drive with the ecu blown and before I had bought the new piece from the junkyard, the mechaninc said that If I wanted to wait to find the part he could put the 'fried' one back in it and that the car would be driveable as it was before with the irregular idle, and then I should comeback whenever I was ready. If anyone can shed some light would be much appreciated.

 

Yep it could be defiantly the fuse i believe not the ecu cause my car starts some times great no problem i will try to use new fuses see if that helps btw i do have a problem when my subwoofer is on and i play music my lights flicker alot what can cause this i only have 300-500 watt amp and diehard battery any clues?