I have had this problem for about 5 years, and I've taken the car to > 8 different mechanics. No one has been able to fix it. The simptoms are: With the car in gear at idle, the engine slows to the point of lugging. At such times, the alternator fails to generate enough electricity to power the car, & the battery drains. Because of this, I've gone through 5 alternators and 6 batteries in this car in 5 years. I've replaced spark wires, plugs, distributor cap, etc. In the process, I had the transmission re-built, & that didn't help this problem either. There is no manual idle speed adjustment on this vehicle. Any suggestions are welcome.

I believe your Camry has the same engine as the 90 model. Is it the 3S-FE (4 cyl)? If so, on the model I had there indeed was an adjustment that could be made to the idle speed, although it's not widely known about, other than at Toyota. This adjustment can affect the emissions, so it's not usually used by regular shop mechanics.

On top of the throttle body, next to the throttle position sensor and near the idle speed control valve, there is what looks like a button, or rubber plug. Pull off the plug and there is an idle air bypass screw that can be turned with a small flat screwdriver. Don't turn it too much, and remember how much you do turn it, so you can put it back to it's original position. 1/4 turn or so should be all that you need. Adjust it while the car running and is in Neutral, parking brake on. Put the rubber plug back in after adjustment.

I'm not sure all the Camry's with this engine had this adjustment. But I do remember mine having a slow idle speed, and being told numerous times there was no adjustment for the idle. I found this on mine while studying the technical specifications on the emission controls.

Dear Don:

Yes, it has the 3S-FE engine. The only repair book I have is a Chilton's manual, which isn't very specific on this topic. I will search for this adjustment when I get home, & see what I can do with it. If it works, I'll let you know.

I did the same thing to my 89 Camry. Runs a lot better but the exhaust is worse now. I have heard that the exhaust is a downside to increasing the air flow (mixture).

What do you mean by "...the exhaust is worse now."?

After I adjusted mine, it still passed the Connecticut Emissions test. The emissions after adjustment weren't anywhere near the limits allowed for the '90 model. It passed with flying colors. A small adjustment shouldn't adversely affect your emissions. If it does, than there is likely other issues, such as an improperly adjusted throttle plate position (butterfly valve position) at idle.

When the mechanics replaced the shaft seals, timing belt and pulleys last year, they also noticed that the PCV valve, as well as the hoses leading to it were filled with deposits. They changed those, and the car stopped burning oil, quite a feat for an engine with 150,000 city miles on it. Zeek1403 might want to try that also to improve the emissions results with his own car.

The 89 4 cyl Camry does not have a PCV valve. If your Camry has a tach, adjust the hot idle speed to about 700-800 rpm in neutral or park with no accessories such as AC or headlights in on position.

My camry has no tach or idle adjustment. My mechanic called the valve mentioned above the Pollution control valve, & showed me from where it came from. It is very hard to get to without removing a lot of the side engine compartment panels, something I wouldn't recommend a home mechanic try

Actually the idle air adjustment screw is easy to get to, if it's there. On some cars, I think there was a metal plug (difficult to remove) rather than the rubber one. Just by opening up the hood, you can see the area right on top of the air intake system very near where the butterfly valve is (toward the back, on top). It's part of the throttle body that sticks up there with either a metal plug of the rubber one. No panels to remove to get to it. I'm not talking about the pollution control valve.

Does your car have a California emission system in it? If it does, then there's probably no adjustment.

It doesn't have the Cal. Emmisions package, but the part you mention does have a metal cap that I am reluctant to destroy to get through. It obviously is not something that Toyota wanted owners to tinker with, if the idle adjustment screw is under it. I've been compensating for the problem by shifting to neutral before stopping, and left-foot braking, which frees the right foot for keeping the thottle open a bit to prevent stalling. The car idles OK in neutral, which is why the mechanics say the idle is set correctly; the problem occurs when the car is stopped in Drive mode.

i own an 89,a 91, and an 87 camry 2 of which have automatic transmitions and both have had a simalar problem they all have the valve of which they speak next to the TPS onthe throttle body if there is a plug remove it. it will NOT harm anything. once you do that turn the screw counter clockwise 1/4 turn with engine running in nutral and parking brake up. once you have done that get in the car and put it in drive if it still run ruff turn 1/4 again untill it runs smooth.

putting it in nutral is the half-ass way to fix it

if you have any questions or if you would like a pic of where the screw is e-mail me at wolfgang_iceclaw@hotmail.com

Thanks for the tip. I found the screw under a metal cap, but I didn't touch it. In the emissions control section of a Chilton's manual, it mentioned an "Idle Speed Control" on the throttle body & how to test it. I did, mine was bad, so I ordered a replacement. I spent all day last saturday on this, & when I put it back together, the car was dead. I towed it to my mechanic on Sunday afternoon, who said that the "igniter" and distributor had both failed. He assured me that what I did had nothing to to with these failures. I get the car back today, so I'll soon see how well its working now.

Folks, ite idle problem has been finally repaired. When I replaced the Idle Speed Control sensor, the car stopped working. I towed it to my favorite mechanic, who found that 1) the igniter 2) the distributor and 3) the mass air control sensor were all bad. These were replaced, and now the car idles as it should. My mechanic thought that the air sensor was the original source of the idle problems I was having. If anybody else is having an idle problem, perhaps they should also test the function of this sensor. It is located in the housing covering the air filter, and needs to be replaced in one large piece.

Thank you for your updates. Very glad to hear everything's fixed and running properly.