High RPM's for no reason
 

I've got a wierd problem with my i30.
Basically what happens is when I've been driving my car for a while (usually in stop and go traffic), I'll notice that without even touching the gas pedal I'm doing 1500-2000 RPM and can go upto 20 mph. I have to really hold down the brake to keep my car from jumping.
If I then switch into neutral or park, the RPMs rev upto 4000 - 5000, and stay there until I turn the engine off.

I've tried to explain this to the infiniti dealership, they hooked it up to the computer and said it was fine, and looked at me like I was crazy.

I have no clue how to go about fixing this problem, when the dealer says it doesn't exist, but I can't drive my car in the city since, if I let up on the brake a little I could plow down a couple of pedestrians.
Also the engine somtimes has trouble starting, but always does on the second try...don't know if thats releated.

Thanks to anyone that can shed some light on this!

Car:
2001 i30 30k miles, auto

sounds like your gas pedal is sticking, or your floor mat is touching the gas pedal? or possible your idle needs adjusting BE CAREFUL

The first thing I tried was to pull up the pedal, and thats not it.
And if my idle needs adjusting, why would it I be idleing at 900rpm's normally but at 1500 when in stop and go traffic?

is ur OD on or off?

OD would do nothing

well, im just thinking on a hunch that there may be something wrong, given that OD off does give u higher rpm's, and possibly there was sumthing wrong, just an idea to throw up

OD is on, I'll try turning it off next time, but I thought OD only had an effect when cruising at higher speeds

od is your final 4th gear.

OD has an effect on your all around rpms

Could it be an impropertly adjusted throttle cable? also, i think someone should make a sticky about the purpose of the o/d off switch (4th gear lockout) b/c there are a bunch of people (not just in this thread) that dont really understand what it does. just a thought, not trying to offend anyone who doesnt know what it is supposed to do.

yes that all important O/D switch is causing his revs to soar to 4-5K rpms in neutral :rolleyes:

If they checked the ECU and found no codes, do what the above person suggested. Adjust the throttle cable and see if that helps, clean the TB, it might be sticking. Did you dealer even drive the car? If so, go to another one if they didn't notice that soaring revs. It should be clear as glass obvious that something is wrong if what you describe up above is happening.

I Had Exact Same Problem...
 

check the rubber hose which connect to the EGR valve.
It's EGR valve over heating problem.
your coolant might leaking some where.

Dealer took week to found that problem and replaced hose.

why is ur idle at 900....

The problem is that this only somtimes happens, usually after I've been driving for an hour or so in stop and go traffic. And the dealer did drive, but said the car was in great shape.
How do I adjust the throttle cable, is it somthing I can do myself, and what is the TB?

sweets_green........looks like vaiorian has your answer,
"check the rubber hose which connect to the EGR valve.
It's EGR valve over heating problem.
your coolant might leaking some where."
this looks like a simple check on your part before you mess with the throttle cable.

vaiorian. awesome, thanks!

don't try to adjust throttle cable. you dont need that.
just check what I told. my dealer took few weeks to find out that problem.
that was year ago. car runs great until now.

good luck man.

:sprint:................

Follow-up:

About a month ago I brought the car to the dealer and made a big fuss.
I told them about what you guys told me on the board (about the EGR valve).
Eventually they said they would replace the hoses and the idle air valve, and I assume they did since they had the car for a day.

I thought that fixed it, I didn't have the problem for a month, but it came back.

Anyway, I ended up taking the car back to the dealer I bought it from, who I trust alot more.
After looking at it for 30mins the I saw the mechanic laughing. I asked him what was up and he said the the problem was so simple.

Turns out the cruise control cable was too tight, and was catching on the throttle cable. Thats it. If the dealer would of taken 10 minutes to actually look at the engine instead of the stupid computer, they might of saw that.

Anyway thanks everyone for your help.

Not suprising at all....

Oooo who called it on the throttle cable(throttle, cruise...almost the same thing)! lol...