00 Camry 4 Cyl, STILL WANTS TO STALL!!!!!

[vertigo14k]

I posted a thread like a month ago about my car wanting to stall at idle. Well after trying to clean it thoroughly, did not work so I replaced the IAC (idle air control valve). Well just a day after I replaced it, it started doing the same thing again. Everytime I'm at a stop sign it idle's like at 600 rpm, and then it wants to stall but it doesn't. First of all, why is it idling so low? Second, if the IAC was replace why didn't the problem go away? I still have not gotten any check engine codes. Anything will help, before I take it back in to the mechanic and he tells me something else.

[fenixus]

yeah those cars do that, even when you set precisely to idle at 700ish it will sometimes vary due to accessories running. a/c and cooling fans or even radio/speakers can change something a tiny bit. once all those little things add up car can go for a moment into 600ish rpms at full stop with brakes depressed, though after a second alternator should compensate the current and rpms should go back to e.g. 670 when cooling fans still operate, once they stop it goes back over 700 and that little vibrations/shakiness disappears.
that's normal.

OP may have worn engine mounts that can cause further shaking and vibrations more intensive or loud. i ended up replacing all engine (3) and transmission mount. now is much more comfortable.

adjusting that throttle adjustment screw affects only engine speed in Parking and Neutral gears. in Reverse, Drive, 2 and L computer still fully controls engine speed with all consequences. for some time i had that screw adjusted up to 1,000rpms in P or N, but still in D&R computer was enforcing around 700-750ish. though such big difference in engine speed makes shifting in parking lot more harsh and i think caused my mounts to wear off faster, causing even more vibration and shakiness. adjusting that screw changes throttle position at idle and having it wrong (plate stays a little open at idle) can screw up vacuum for EGR and brake booster - bottom line it's not worth it to play with that screw, leave it alone at factory setting.

[vertigo14k]

I did clean the TB thoroughly, so don't know why the problem didn't go away.

[fenixus]

when was the last time you did tune up and what is its mileage ?

[vertigo14k]

2k miles ago, the mileage is 155,000. I try to do a complete tune up every 3K miles.

[carsrus]

Check the big hose the connects the airbox to the throttle body for cracks. Sounds to me as if you might have a vacuum leak.

Take some carb cleaner and spray down the hoses with the car running. If the idle smooths out or the rpms increase you have a vacuum leak at that location.

600/700 idle is pretty normal. Sounds to me like a hose splits open when you slow down. Does it also do it when your in reverse?

[93celicaconv]

You do a complete tune up every 3k miles? What is all included in your complete tune up? How many miles does your 2000 Camry have on it now?

[vertigo14k]

I change the oil, oil filter, spark plugs, and air filter on a tune up. I have already changed the pcv valve, vsv for evap. cuz I was getting code p0402 and also replaced the gas cap. That code hasn't come back. But when that was fixed it was when I started getting this problem.

[93celicaconv]

I don't know how long you've had your car, but new spark plugs every 3,000 miles, you've been connecting and disconnecting your spark plug wires a lot. You might want to measure the resistance across those wires and see if they still test good. Otherwise, not a bad idea to replace the plug wires, to rule them out.

When you start the engine cold, does the engine have a high idle (say 1,200 to 1,500 RPM), then gradually slows down as it warms up?

[vertigo14k]

I changed the spark plug wires already and it's still doing it. Yes when I start the car cold it idles at 1200 to 1500 rpm, then gradually lowers down. When it is fully warm and the temperature needle is in the middle it's when the car starts acting up.

[93celicaconv]

Is your EGR valve vacuum operated or electronic? I don't have anything as new as a 2000.

If vacuum operated, just to rule the EGR system out as a cause (it could produce your symptoms), remove the vacuum line at the EGR valve. Does the engine still want to stall when warmed up and at idle?

[hill8570]

This isn't a vacuum leak -- a vac leak on a 5S-FE gives you a high idle, not a low one.

Kind of a long shot, but try pulling the connector for the ECT (after the car is warmed up). Follow the upper coolant hose from the radiator back to the engine -- the ECT is the green connector near where the hose goes into the engine. If your idle drops back to something more normal (say, 700-750), then your ECT is reading too high of a temperature.

Hmmmm. LA area, so might already be A/C season. Does it matter if the A/C is on or not? There's a A/C idle-up valve that's supposed to kick in when the compressor kicks in...if it's not working, your idle is going to drop when the A/C kicks in.

[fenixus]

Originally Posted by hill8570

Hmmmm. LA area, so might already be A/C season. Does it matter if the A/C is on or not? There's a A/C idle-up valve that's supposed to kick in when the compressor kicks in...if it's not working, your idle is going to drop when the A/C kicks in.

i'm sorry to jump in, can you tell more where this idle-up for a/c valve is and how to see if it works fine ? i noticed my car going into 600ish rpms when idling at full stop (d gear) with brakes depressed and a/c on (and compressor running).

[vertigo14k]

Problems has been fix, and I appreciate everyone's help! I guess there was a bad wire in the spark plug wires. They came out defective, it was barely noticeable. The mechanic said when I would drive at speeds higher than 10 mph, something about the charge going all the way through the wire. At idle sometime the charge wouldn't make it. So it would misfire.

[93celicaconv]

Better get a refund on those spark plug wires (you said you had just changed them in a previous post). Who was the manufacturer of the previous wire set? Would be good to know that, at least in your case, they came defective, so others are aware of this manufacturer.