Engine shaking, Please help

[stanleyeye]

My car is 98 camry LE. It has no problem at all when I drive it locally. Last time, after I drove at a speed of 75mph on highway for about 5 minutes, the engine became shaking greatly when I was waiting for the traffic light. The engine speed jumped back and forth between 0 and 1000rpm. After a while the engine went dead. I strated it, same situation. After several minutes, I started it again. It became normal. I drove back at a lower speed. I had met this situation before. I asked the dealer to check the problem. They told me to replace spark plugs. I did it two months ago, but it seems that did not solve this problem. I am guessing something wrong with my EGR system. Could anyone give me some advice? I really appreciate your help.

[tvn_1010]

Originally Posted by stanleyeye

My car is 98 camry LE. It has no problem at all when I drive it locally. Last time, after I drove at a speed of 75mph on highway for about 5 minutes, the engine became shaking greatly when I was waiting for the traffic light. The engine speed jumped back and forth between 0 and 1000rpm. After a while the engine went dead. I strated it, same situation. After several minutes, I started it again. It became normal. I drove back at a lower speed. I had met this situation before. I asked the dealer to check the problem. They told me to replace spark plugs. I did it two months ago, but it seems that did not solve this problem. I am guessing something wrong with my EGR system. Could anyone give me some advice? I really appreciate your help.

Do you have a check engine light? If there is no check engine light, then probably it is not the EGR system.

[Cammy_01]

Originally Posted by tvn_1010

Do you have a check engine light? If there is no check engine light, then probably it is not the EGR system.

It is possible the EGR could have developed a vacuum leak and this may not throw a code. This is will usually cause a minor to major rough idle, but not so noticeable while at cruise speeds.. a simple check is to squirt a little carb spray on the EGR and see if the idle increases.. if so then replace the EGR if not and no code then it is probably ok.

Sometimes if the TPS sensor is going bad it will do the idle hunting as you mentioned.. usually there is a code for that as well. I would check the air filter, change the fuel filter and perform diagnotics per the manual to verify the TPS sensor is performing correctly.

[stanleyeye]

The check engine light was on, and I checked. There is no code. I think the check engine light will automatically be on when the engine idle speed is pretty low.

Originally Posted by tvn_1010

Do you have a check engine light? If there is no check engine light, then probably it is not the EGR system.

[stanleyeye]

Thanks for you help. I will check the EGR valve leak first by using your way.

Originally Posted by Cammy_01

It is possible the EGR could have developed a vacuum leak and this may not throw a code. This is will usually cause a minor to major rough idle, but not so noticeable while at cruise speeds.. a simple check is to squirt a little carb spray on the EGR and see if the idle increases.. if so then replace the EGR if not and no code then it is probably ok.

Sometimes if the TPS sensor is going bad it will do the idle hunting as you mentioned.. usually there is a code for that as well. I would check the air filter, change the fuel filter and perform diagnotics per the manual to verify the TPS sensor is performing correctly.

[Cammy_01]

Originally Posted by stanleyeye

Thanks for you help. I will check the EGR valve leak first by using your way.

Let us know how it goes or what is was..