Stalling / EGR valve

[fengmit]

My Camry 98 (86k) stalls intermittently at stop sign right off highway. Dealer replaced EGR modulator and vacuum switch valve and didn't fix the problem. Disconnected EGR system to test if EGR valve is the one having problem. Test drived 3 days w/o EGR and had no stalling. My friend helped me cleaned the EGR valve (was clogged with carbon) and run for 2 weeks (70miles/day) w/o problem. However, it happened again yesterday. I took off the valve and checked today. The valve moveed up and down ok when I pushed it by hand and also by mouth (simulates vacuum suck). Found only a bit cotton debris around the shaft, probably from previous cleaning. I did another round of cleaning anyway (use brake fluid). After I finished cleaning and put it back, I did a EGR valve test following instruction from Haynes manual: I started engine and let it idle, detached vacuum hose from the EGR vavle, then put the hose in my mouth and gave it a suck (manual says to use a hand vacuum pump - I checked Carquest cost $50). The engine stopped right away after the suck (opened the EGR valve to let exhaust gas back into engine). According to the manual, when apply vacuum to the EGR vavle, vacuum should remain steady (no leak) and the engine should run poorly (EGR valve should be closed at idle speed or will run poorly - my guess).
My concern is my case is not just running poorly, but stopped completely. Does this indicate anything else may be wrong? I tested again when engine was warmed up to normal, it took slightly longer to die. Does anyone know when exactly the EGR vavle should open and close? I'm still try to figure out whether the vavle is the problem or something else. I think the best thing for me to narrow this down is to disconnect the EGR again right after it stalls again (hope not happen anymore, though)! Any other suggestions / thoughts would be appreciated.

[Erndog1369]

EGR valve is mosly likely sticking. As you come off the highway, and vacuum decreases to the EGR valve, the valve is not closing all the way. I have tested them (off the car) many times and very rarely do I physically see the valve stick open. I have seen it though on rare occasions. Nevertheless, replacing the valve has always fixed the problem.

[fengmit]

You've a very good point. The valve may be functioning differently in real world than when you see it off the car. Have you ever tried to test the valve like I did? Was the engine run poorly or die?

[ToyotaTech]

It the die I too am a ToyotaTech I have tested like u and It will die!

[fengmit]

Thank you. I feel better now. I hope it's the EGR valve problem, nothing else. I drove 35 miles highway this morning and it went ok w/o stalling. Will keep watching.

[TheRyanator]

I was told by my mechanic that I have the same problem with my EGR valve...he said if it happens again to just take the valve and clean it. Only problem was that I picked up my car at night after he had left and so I was not able to have him show me where it was located. Could anyone tell me where it is located in the camry and what to clean it with? thanks!

[Joe W]

The EGR valve is located by the throttle body near the linkage.You can clean it using a wire brush-solvents are NOT recommended.

[jokerji]

Could someone tell me in detail on how to clean the EGR valve. I'm getting the same P0401 message and the infrequent car stalls and would like to get this over with!!

[gator2764]

Originally Posted by jokerji

Could someone tell me in detail on how to clean the EGR valve. I'm getting the same P0401 message and the infrequent car stalls and would like to get this over with!!

I have cleaned the EGR on my Tercel a few times. I have used carb cleaner, the spray, and q-tips. Just don't get the spray in the diaphram (stay away from the rubber vacume lines). I am not sure about the Camry but there were two ports going into the intake from the EGR valve that were completely clogged on my car. I had to take a screw driver and pick the carbon out of these. I had to use some spray between picking. If you can take the EGR off and the car doesn't run any different those ports are clogged. It takes about 30 minutes to clean it all out but it has worked for me. With 178K on the tercel I have found out that I need to remove the EGR about every 25K now. Make sure you get all of the little pipes cleaned out as well that might be sticking out from the EGR. Hope this helps

[jokerji]

Is there a picture somewhere on the internet with step by step instuctions? I am a newbie when it comes to car mechanics...

[gator2764]

Originally Posted by jokerji

Is there a picture somewhere on the internet with step by step instuctions? I am a newbie when it comes to car mechanics...

None that I know of. I think all it takes is 2 nuts and a tube that needs to be removed. A few vacume lines should need to come off also. If I remember from looking at my camry that metal tube looks like it will fall apart when you take it off. That can always be purchased at the dealer though. Start sparying some penetrating oil on those part and let it sit for a few days.