EGR Operation?
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
The EGR valve will remain closed until the ECM commands it to open. The ECM uses input from the ECT sensor, TPS, and MAF, to determine when to open the valve. I don't think it is necessary for the ECM to be in closed loop, but I'm not sure on that. The EGR should remain closed at idle and at WOT.
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Thread Starter
Racer
Joined: Jul 2006
Posts: 319
Likes: 0
Egr
The reason I ask is that I forgot to reconnect the EGR temp sensor after checking my EGR solenoid. I get somewhat better gas mileage and a smoother idle (still hunts, but doesn't drop down to 440 RPM at least..) with the temp sensor unplugged. My thinking is the EGR is either causing or contributing to my irregular idle problem, that is, if it remains closed at op temp with the temp sensor unplugged. I realized the sensor was unplugged because I set a code 32 on a few warm days after fairly long highway drives. The 32 is very intermittent; when I turn the car off, the CE light goes off.
One other thing; I noticed the temp sensor female plug has been spliced (wrapped with electrical tape). Maybe it's spliced incorrectly?
One other thing; I noticed the temp sensor female plug has been spliced (wrapped with electrical tape). Maybe it's spliced incorrectly?
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
My car doesn't have the EGR temp sensor and therefore I am not very familiar with it. I think it's only function to assure the ECM that the EGR valve has actually opened when it was commanded to. Regardless, the ECM is not going to open the EGR at idle, and therefore the heat sensor shouldn't affect your idle quality. EGR leakage at idle would cause idle problems. You may want to check that it is closing fully when it closes.
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Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
On my '85, it was very quick and easy to see if the solenoid and valve were working correctly. I don't have the steps off hand, but if you do a search you should find them quickly.
If nothing else, I'd take off that electrical tape and make sure you have a good connection there. Use solder to bond the wires and then a little shrink wrap to finish the job.
If nothing else, I'd take off that electrical tape and make sure you have a good connection there. Use solder to bond the wires and then a little shrink wrap to finish the job.
