My 99 SE is often idling too low (500-600RPM) and shakes a little when it does. What I'm doing to correct:

- Clean intake and throttle body by removing airbox and scrubbing inside with cleaner
- Clean MAF sensor with alcohol and q-tip.
- Clean K&N filter

Anything else I'm missing? It has new plugs, fuel filter, and the coils are good (I think). It's not throwing any codes either.

 

I would try adjusting your IAC valve (Idle Air Control Valve). There is a how to in the Stickies on how to clean this. What the IAC valve does is it allows air pass through to the manifold, which increase or decreases idle speed. The more air passing through the valve the higher the Idle and so fourth.
Another thing you should check is the Throttle Body cable, check to make sure there isn't any excessive play.

 

I replaced injectors and it took care of the shaking problem.

 

Is it possible to have a bad fuel injector without the check engine light popping up?

 

Good question mb. I was wondering the same thing - mine is throwing no codes.

 

From what I remember, I had a multiple cylinder misfire.

 

ouch i had that on my last car.. teh gay.

 

My car idles at 600 RPM just fine....

 

You may try checking if your catalytic converter is plugged by checking the vacuum strength of your engine...

 

i would check the IAC too.

 

Just finished cleaning the IAC - not really a whole lot to clean in there. Took it off, cleaned it out, took off the plastic bit and cleaned that too. I can still feel through the steering wheel rough idle, but it's now at 700rpm - right where it should be. I also reset my ECU.

Last fall I decided to go with G-Power NGK plugs when I did my 98000km service. Is this the cause? They're not expensive plugs, but they were the second most expensive at Canadian Tire next to the Iridium ones.

Anything else I can do? Vaccum is great too btw. And there are no codes.

 

My car idles find at around 600rpm.......... I have very very little shaking, no codes...... It may just be that way, after all its no lexus.

 

Good point dave. It doesn't idle perfect, guess I'll have to live with it.

 

I would look around to see if anyone in your area does a Fuel System Service. This usually includes some strong detergants that they run through the fuel system and it cleans all the gunk out of the injectors etc. I know acouple of people who have done this and they say there was a noticable difference in how smooth the car ran after.

 

More importantly check your harmonic balancer, make sure is spins freely, and that it has all the rubber on it! If your harmonic balancer is not working correctly that needs to be adressed ASAP!

Also i would like to say that my max rumbles and shakes in reverse like a muscle car when its not warmed up, try all your gears and check which gears it shakes in. Also try this after your car is warm! But seriously make sure harmonic balancer is ok or your engine may be shaking itself to death.

 

Try BG intake cleaner.It's good stuff.

 

I think he needs to look at the big picture, then he can look at the small details like the intake etc...