EGR position sensor test - code 31

[kimcrwbr1]

What would be nice right now would be a vacuum gun.
http://cgi.ebay.com/ebaymotors/Hand...t=Motors_Automotive_Tools&hash=item566eab57ed
A pressure guage will work as well you need to determine if the system is holding pressure and or follow the path from manifold to the EGR. Are you getting vacuum pressure to the EGR when you work the throttle?

 

[kimcrwbr1]

My book shows a v-reserv usually indicates a vacuum reservor in the path to the EGR. Maybe try putting all new vacuum lines on and eliminate the hoaky plastic ones that have a tendency to plug or crack. My book shows code 41 as the oxygen senser (EGO) or vacuum issues. Vacuum being the common denominator.

 

[swingjunkie]

Ok, I put a vacuum gauge on this over the holidays. At the vacuum tree I have 21" Hg . No wiggle, no jiggle, steady as a rock. I then connected the gauge between the vacuum resevoir and the EGR. As expected tthis reads 0 "Hg at idle, and when I rev it to about 2000 RPMs I max out at 6" Hg on the EGR. Vacuum lines on this engine are tight, so tight they are difficult to get on and off, so I do not suspect any vacuum leaks. I also went round all the hoses one more time with propane and not a wiff of any leaks.

I exercised the EGRV and EGRC solenoids extensively and thouroghly flushed them with WD, as suggested in an earlier post. As best I can tell they are working as expected.

I put on a new O2 sensor which cleared the code 41, so the only remaining engine code is the code 34 (EGR did not respond as expected durng the KOER test). My only thought on this is that the EGR port in the upper intake manifold is plugged. I have a set of fuel injectors to install when time permits, and when I do that I will pull the upper intake manifold and see if that is the case. I'll update this thread when that happens.

Thanks for all your suggestions and ideas on resolving this
Happy New Year
Carl