Well, I've had my EGR blocked off for the last couple of weeks and several people here have convinced me that I need to fix it. So, off to the parts house and I've got a brand spanking new EGR valve for $60. Just put it on today. Cranked and ran fine, then, about the time it warmed up well enough to throw the solenoid, I get a major miss and stumble that won't stop. Really hard to crank and won't stay running if it does. Humph! So, I check for whatever. Loose wired, tubes, etc. Everything looks fine. The EGR however will not hold vacuum! Looks like the diaphragm is blown and it is stuck open! Now, here is my question. What could cause this? Man I hope I don't have a cracked head. The old diaphragm will hold vacuum so I know it didn't blow the diaphragm, it just causes a stumble when it opens. I guess my SOL luck struck again and I got a bad valve..? If I don't hear some words of wisdom soon, I'll just pull this off and go exchange it to try again... Russ 85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.