Checking EGR valve

[Grim Reaper]

Originally posted by Old Chevy Lover
So, does the EGR help/hurt/not affect gas mileage? I started driving my suburban a couple weeks ago. Idle was rough, and #8 plug kept fouling out. Messed with it, and messed with it, finally pulled the vacuum line off the EGR one day, just seeing what it was. Full vacuum, all the time. Motor immediately jumped up to about 800 RPM idle, purred like a kitten. I just left it unhooked, as I thought something was bad with it. But, after reading the above posts, sounds like the EGR is functioning pretty well, I just gotta find the right vacuum port to hook it to. Oh yea, #8 plug hasn't fouled out yet. Just pulled it out tonight. You can still tell there is some oil getting by the rings, but, so far, its still firing.

If the engine is designed for the EGR itns susaly not taking power and it quite honestly might make it have more power. It helps prevent ping/detonation.

Look on the cores suport and see if the Vac routing sticker is still there. It will tell you what port it needs to be hooked up to.
With that EGR being hooked to straight vac it may have caused some other problems. It may have carboned up the EGR passages if it's been that way a long time.

[Old Chevy Lover]

I don't think the sticker is still there, but I will have to look again to see. I'm thinking the core support had been replaced due to an accident at one time or another. It has the fact. elec carb on it, and from memory, I'm thinking there are 2 vac ports on the front of it, and one on the bottom corner of the passengers side. I know the drivers side front one is the full vacuum at idle, but haven't checked the other two yet.