Low RPM Problem

[LancerImpact]

Didn't think I would be making a thread so quick after my previous one, but I just remembered a problem that I am recently experiencing.

When I start my car, the RPMs will drop so low that it will stall unless I give it some gas after which it stabilizes, but the RPM is still only at 500 which is really low even for idle.

Even when I am driving and I pull up to a red light and put it in neutral, sometimes the RPM goes so low it shudders and then goes back up. (and no its not cause of my shifting)

ANy idea what this means....

[King]

When's it due for a service?

[LancerImpact]

When's it due for a service?

I spent $1k on service about a month ago.
Oil change a week ago.

It just started happening....

[Dogbert]

Not sure what make/model of a car you've got but I'll just guess it's fuel injected.

It sounds like, to me, like you've got a dirty throttle body. It's really easy to clean, and very inexpensive. If you're not sure where to find the throttle body, you can Google it and it should come up with some good results. You'll also need some carburetor cleaner to clean it with, which won't cost much.

What happens is this, the throttle body gets clogged with carbon and eventually can't breathe. The throttle plate (another piece you'll need to clean) is inside the throttle body, when your car is at idle the throttle plate is closed, allowing in very little air. With carbon build up, it can't breathe at all and will eventually stall out.

Or you can take it into the mechanic and tell him your problem, he'll probably charge you an outrageous amount for little work.

Good luck! You can ask for help if anything was confusing, I'll be happy to help.

[DAMINK™]

I dont think its throttle body.
The EMS is supposed to compensate so a sticky butterfly would most likely increase the engine revs i would have thought.
I would be looking at a vacuum leak as a first look.
Possibly second would be a filthy fuel filter that is restricting engine revs but that would be felt through the whole engine rev range.

[LancerImpact]

Its a 2003 infiniti g35 coupe

i did some research and it seems like a common issue lol

i think i will just take it to the mechanic IF he doesnt charge a lot.
i looked up a video on cleaning it and well its quite a job lol

[Untitled]

A 500 RPM idle wouldn't provide good enough oil pressure would it? If you hear it MISS, not just drop RPM then it's your distributor cap. If
you have one that is.

[LancerImpact]

I actually took it to the shop because the engine would not start at one point.
They had to replace the cam sensor bank.

The low RPM is still a problem. They said I would either need
a. idle relearn
b. throttle body assembly/cleaning

I left it as it is now as they wanted to cahrge me +$100 plus for each.
This pissed me off because I know idle relearn literally takes less than 5 minutes.

Am I doing any damage to the engine if I leave the RPM problem as it is?

[ktmrider530]

Sounds like there is a problem with your computer. Like a sensor. Posibly a fuel filter/pump/sending unit. It's really tough to tell without actually seeing it. If it idols low, I would check your MAS if it is defective, your computer will adjust fuel flow to sompensate for air.

[Untitled]

Throttle bodies can cause bad idles yes, but usually not to the point of stall. Idle relean like they said would probably do it.