So i noticed that my car had a wierd idle about a year ago, but it had stopped until yesterday.

I own a 99 GXE

Yesterday when i would put in the clutch when i was moving, the RPMs would not go below around 1100rpms then slowly go up to 2000rpms then make the sudden drop to 1100rpms again. It would continue this if my car was moving when i had the clutch in. If i came to a stop light, it would do it every once in a while but in the mean time the rps would not go below 1100 again. When it does this, it does it all day and doesnt stop. It doesnt do it every day though, but when it does, its bad.

Anyone ever heard of anything like this and can help?

Here is a video of the rpms going up and down while i was going down a small hill.

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Thanks for looking

 

anyone?

 

Are you getting any codes at all man? Make sure you're not getting any codes at all first but its starting to sound like you've got a vacuum leak somewhere. Do a search for that and/or erratic idle and see what you get- i'm sure there's a ton of folks who've had similar issues.


Anyone else with better ideas, feel free to jump in..

 

thanks ill check

 

by the video it looks like the tps is shot. i would change that. if that doesnt help check your vacuum lines but i doubt its them with a 1000 rpm jump like that

 

TPS?

 

throttle Position Sensor. Its connected to TB and tells the ECU the position of the TB either open or closed. Use the FSM and multimeter to check voltage when open and closed. THink it shd be 5 volts. Check IACV too.

 

it should be 4.8-5 volts at wide open throttle. at closed throttle it should read like .03 volts.

 

ok, will do. Again, it isn't consistent, just today it wasn't doing it again.

 

The rough idle and/or stalling issue is pretty common. I too will be in the process of checking TPS and for vacuum leaks for a similar (though more exaggerated problem). I can actually hear the loud vacuum sucking noise on my car, so it should be easy to find for me.

Scroll to page EC-150 in the following link to read about your TPS in a 1999 Max. If it tests okay, then check for vacuum leaks, but as previous poster suggested, your jumps sound more sensor related than leak related.

http://www.nicoclub.com/FSM/maxima/1999/EC.pdf

 

Nice. Thank you for your help.

 

Xfactor,

Have u cleaned your TB. If there is enough gunk in there it can cause rough idle (by rough i mean that the rpms will surge and dip). Clean TB and MAF per the how-tos if u have never done so.

I jus cleaned my TB and MAF last wknd. Every 3 months man, jus like an oil change. Its prevenative maintenance man....welcome to the maxi world. Also took some WD40 and sprayed rusted bolts, cleaned intake inlet and topped off fluids

 

cashoit,

Thanks for the welcome lol. I am about due for a cleaning under the hood, since i have never done it since ive owned my car. I will most definately check out the things you said, thanks for your insight.

Do you think weather can manipulate how the damage may effect the engine at certain times? It really only happens when it rains or is humid.

 

It really only happens when it rains or is humid... thats opens up alot of new things that could be wrong. that probably means that water is getting in somewhere it shouldn't be and is shorting one of the sensors out.

 

O u have a 99???

They have coils that have been known to fail. A blown or malfuction coil can cause random power loss and misfiring. there was a thread on here where I have hrd that rain can cause the coils damage to be more prominent than when its dry outside.

But before u start spending big money, try the cleaning and throw some chevron techron in the fuel tank. If u still having problems afterwards start looking at coils and TPS issue. Dont worry too much man... ur car is org fixable. Hell, we been able to diagnos Daniel's, Yota, and WXM car. SHOUT OUT to those guys!!!

now THEY were havin issues lol.

 

next time it does it take some wd 40 and spay it on the wires to the sensors and coils and see where it snaps out of it. or on a dry day when it itsint doing it take a bottle of water with a spray top(like a windex bottle or something) and mist it over the electical parts of the engine and see if you can get it to act up.