I'm thinking of buying a 94 Camry, however the seller says that if the air is on, the car runs great for about 20 minutes, then starts riding rough. It runs great if the air is off. Any ideas what could cause this? Possible fixes? I'm not sure if this is related, but I noticed that the air was extremely cold when I test drove it, even on the lowest setting.

 

Does it run rough cause the engine idle speed drops excessively? If so- does it run smoother if you slightly increase the engine speed with the throttle? You may just have a failed IAC valve- which controls idle speed. The IAC valve should raise the idle speed slightly to compensate for the load the AC compressor puts on the engine.

JJ

 

Thank you for responding. I found out that it's actually a '92 Camry and the problem has nothing to do with the AC(it just runs a little rougher with the AC on). Sometimes it drives with no problem, but other times if you stop at a light/stop sign etc. or even slow down and then try to go again, stepping on the gas only makes it sputter and try to stall. You have to let it go at it's own pace until the engine begins running normally again. We tried cleaning the IAC valve and that seemed to help slightly, but it's still pretty much undrivable. It seems to be flooding itself anytime it goes idle, which would suggest that it's not getting the proper air/gasoline mixture. Any other suggestions would be really appreciated.

 

Hi, Our 1996 Camry has been acting weirdly for over a year. And I've read similar posts over the past year of similar symptoms. The RPM used to vary while at idle, sometimes going up to 2K and back down to regular idle. I replaced the coolant sensor and thought I had fixed the problem. In a sense I did, whereas it doesn't have those huge idle swings. But as others have described, you never know when the car is going to start running rough like the engine wants to die unless you give it some gas and take RPMs up to at least 1K. Of course this always happens at an intersection so nobody in the family wants to drive the Camry anymore. Our Camry is very clean with only 75K original miles. I purchased it from original owners a couple of years ago. I would really love to solve this problem so if anyone has an idea of what this gremlin could be, please let us Camry owners know your thoughts. Funny thing is the computer does not show Check Engine or any codes so when you take to a mechanic, they have no idea what the heck is going on. And the car usually runs perfectly (behaves) while at the mechanic. Thanks to all, Mitch

 

Does it run ok when the engine/ambient temp is cold, but starts this problem once the engine is at operating temp?

 

Yes, I would say it runs fine when cold and during warmup. The problems seem to occur mostly after engine has warmed up and has been running for awhile. Sometimes the rough idling will begin after a quick stop such as when a traffic light turns yellow and you need to stop cause you're not going to make the light. I don't mean slam on the brakes, just a quick stop. And there are times when the car runs absolutely perfectly with just a very slight vibration in DRIVE with foot on brake.

 

Does this only happen with A/C on? If not then first I would clean the IAC valve, if that doesn't fix then it sounds like you could be getting too much fuel. You've already replaced the ECT so two other possibles could be your evaporative system and the MAP, but also don't discount a vacuum leak. For the evap system it could be blocked canister, defective check valve, bad seal on the gas cap, or vacuum leak in the hoses.

The MAP can be tested with a volt meter and vacuum pump - the voltage will be about 3.5 - 5 volts without engine vacuum (ignition on - engine off) and 1.5 to 0.5 volts with about 25Hg vacuum. Use a paper clip to back probe the connector.

 

I'm probably going to clean or replace the IAC valve. While I'm at it, I'm going to check all the other components in that area and replace the smaller diameter vacuum lines. They all appear to have the same marking so a length of hose should cover all of them. Is there a special solvent to use when cleaning the IAC or Throttle Body. I've heard about the Seafoam brand. Just don't want to damage any metal parts. Thanks, Mitch

 

You can probably use O2 safe carb cleaner. Either spray into throttle body where square hole to IAC is or remove IAC and clean, depends how dirty it is. I don't think Seafoam would work too well here, although I do use it in the gas and through the PCV for decarbing the cylinder. I'd buy a Haynes Manual if you're going to remove IAC, not a bad investment anyway for about $21. Careful not to let the spray can straw come loose and go into the intake.

 

Hi Pedro,

I've been using an online pdf manual which I found sometime ago on the internet. I think that it is the Toyota manual divided into various sections. Has a lot of detailed info although the illustrations are not the greatest. I think someone may have scanned the whole thing. I'm going to take a lot of digital photos so I can get everything back correctly.

I've been looking at the posts from owners with 2002-2006 4cyl engines. What a shame that the bolts are loosening and causing all those problems. Do you know of any issues I should be aware of with my 1996 engine? Is the 1996 engine one of the versions that has a sludging problem? If so, is there anything I can do in the way of preventive maintenance?

Mitch