EGR problem? Driveability

8UWITH6

Keepin' The Shiny Side Up
Joined
Dec 30, 2001
I drilled the hole open for the EGR in my powerplate yesterday after having it blocked off for probably a year in the T-type. It was kinda dirty, so I cleaned it out the best I could. Ever since I put it back together, I get a really rough idle, and lower vacuum (Im assuming because of the rough idle). Im thinking the EGR is toast because after driving for a little while after the change, I popped the hood and the EGR was extremely hot and actually smoking a little from underneath. However, I am going to check for a leak around the vac pod or the upper plenum. Anybody have any ideas? Plugs are also new as of Monday. I had no problems before I drilled the hole for the EGR. Thanks

PICS of EGR off the car:

http://imagehosting.soldiersites.com/data/46/DSC00024.JPG

http://imagehosting.soldiersites.com/data/46/DSC00023.JPG
 
With all the carbon around the EGR pintle, the diaphram may be sticking open. Also, with all the carbon around the underside exterior of the EGR valve, the diaphram may be punctured or defective. May need a new EGR valve, just don't use the aftermarket style with washers to create a specific flow. Especially if you live in an area that uses dyno type emissions test.
 
Put an Autozone (Wells) EGR on it, no washers, seems fine. Car idles and has good vacuum now. We dont have emissions tests........whats wrong with "aftermarket" valves?
 
Originally posted by 8UWITH6
Put an Autozone (Wells) EGR on it, no washers, seems fine. Car idles and has good vacuum now. We dont have emissions tests........whats wrong with "aftermarket" valves?

The aftermarket valves don't flow like a factory EGR valve, plus it was probably never put through the rigorous federal test procedure emissions test. On I/M 240 emissions tests, I noticed that the aftermarket EGR valves would cause HC problems if the restriction was too large and excessive CO and NOx problems if the restriction was too small. The main problem with the restriction being too large (excessive HC) is that (on a engine that was already clalibrated pretty lean from the manufacturer) it created a big lean misfire problem. This problem was not just an issue for our Buicks, but I noticed it would crop up on any vehicle that used a aftermarket EGR valve. Initially the CA program piloted I/M 240, and I got experience using a full blown lab grade dyno.
 
Sorry I haven't answered in a timely manner. My grandmother passed away on Tuesday and I just returned from out of town. But yes, the potential for more detonation does exist. Remember, the EGR sytem doesn't work at idle, full throttle, anything in 2nd gear or lower, and below a specific coolant temp. So, if you add the fact that a EGR system does not produce the correct flow, think how it upsets the mixture. Now some chip burners compensate for no EGR (Jim Testa comes to mind) in the timing map.
 
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