Is there an alternate way of replacing the vavle other than removing the plenum? I need to change the valve because it is really killing my gas mileage right now at warm up. It is not purging enough or any fumes from the charcoal canister at warmup and is compinsating that for extra fuel. I should be getting 18 miles to the gallon but now only 12.

 

Don't know about your '85, but on my '91 I don't think the EGR and vacuum canister purging are related at all.....

And yes, from everything I've seen and done you have to remove the plenum to change out the EGR valve (at least on my '91 before I went with the SuperRam, but it requires that too). Unfortunately, removing the plenum is the easiest part of changing the EGR valve. I had to bend and grind on a wrench to be able to get to one of the 2 bolts that holds the EGR to the manifold. YMMV, of course.

 

I know what your talking about man on my 85 i broke that line for the EGR and charcoal canister horrible gas mileage. I replaced my egr valve it was alot easier then i thought basically it is 12 bolts and a few coolant/ vacuum lines i just took of the plenum and not the runners, not sure how other people do it, but make sure if you do it to get new gaskets. and as for those 2 bolts that hold the egr on if you take your time they come off fairly easy i didnt have to bend any wrenches hope this helped a little.

 

I imagine the reason for the terrible gas mileage was you created a vacuum leak and the the motor ran extremely rich from all the extra fuel the ECM fed into it due to the leak.....