I found a problem with my EGR in my other topic so posting a new thread so more people will see.

I don't know which size orifice washer should I install in my new universal EGR since I don't have an original one to compare to. If anybody has theirs lying around could you measure the orifice and post the dimensions here? Many thanks.

If it has a number on it, it's 11.

I couldn't find a number on mine, but the opening of the one that goes underneath the manifold is 0.230 inches.

Edit: I retract that. I didn't pay attention to the 2.5 engine. My reference is for the 2.8.

[This message has been edited by fierofool (edited 10-27-2019).]

direction should has OEM EGR # = Washer #
If so See my Cave, Emissions for OEM #.

Don't count others saying Washer # because different packs directions may have different numbers.

Must install the washers right or can leak or worse fall into engine.
See same page.

not sure if still have a bad valve to measure size of hole. I'll look later.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Thank you very much. I'll fabricate a washer and see if it helps with the stumble and hunting idle. Will let you guys know in a week or two for future reference.

I bought a 6.5mm orifice washer and seems to work great now. No stumble though still a little hunting idle though much better than before. The originally installed office had a 10mm orifice...

I wonder if I can dial it even better for the hunting idle or is there not going to be any noticable difference or is the hunting idle caused by something else... Could the orifice be too small now?

[This message has been edited by cebix (edited 11-05-2019).]

You should have no EGR flow at idle, so the orifice size should have no effect at idle.

Thanks. Guess it's something simple, it must be. I'm still having the issue from my previous thread and I guess it's possible it's linked to that.

https://www.fiero.nl/forum/Forum2/HTML/140526.html

Acutally now I notice a little stumble/misfire at certain RPMs part throttle, say 1800-1900. It's slight but it is there.

Okay, decided to buy a new EGR from AC Delco without the shimming orifice stuff. Well a Made in China one came in and it has a different orifice then what theogre measured by quite a margin and seems to run the best so far of all my EGRs. Too bad I though it would be an OEM part but it turned out to be Chinese but what can you do... Here are some photos for future reference, the orifice seems to be 10.5mm wide. There's like a washer inside you can see in the photo where the caliper touches and it is loose inside there - wonder if that's how it should be? Car seems to run better, no stumble at any RPMs other than my cooling issue in the other thread. This is for an 1985 2.5 duke automatic w/AC.

[This message has been edited by cebix (edited 11-18-2019).]

Washers are for universal types because fits hundreds or more engines.

ACdelco, Standard and other units like above isn't same and you likely measure the wrong place. This type is gas metered farther in the unit and can't measure w/o taking apart. Or the opening work w/ the inside valve part that move down in the orifice IOW you might measure total opening but doesn't mean much.

When possible, this type work better because can't leak like loose washers in universal ones.

I thought that might be the issue and measuring like I did means probably not much. However the universal one with my washer that matched your measurement was running pretty good but with a little stumble at some RPMs. This one however seems to run good all through the RPM range. Conclusion: don't buy universal EGRs as it's a hit or miss thing especially if you don't know if yours is original.

To not be misunderstood I'm thankful for your measurement since it let me pinpoint what the issue was.

[This message has been edited by cebix (edited 11-18-2019).]