77GCSX

Yep, I have what appears to be a cracked EGR base. Too dark for pics right now but looking at it from the front of the car it appears to go from the carb. side down towards the exhaust manifold.

I was wondering how common this is, if at all. I was going to block it off anyways so it's no big deal but I was wondering if THIS might be causing my issues with the hesistaion from a stop and my cruising at 55 surges. BTW: All vacuum lines have been replaced.

One thing to note: When first started, and it starts REAL easy, for the first 30 seconds to a minute it runs like a champ. No off the line hesitation, pulls real nice and even. It's after this minute mark, when things get warmed up, that it starts acting funky. That's why I replaced the vacuum lines, and while replacing them noticed the crack.

I do have a 2GC rebuild book so that's not out of the question, just checking everything else before I dive in and rebuild the carb. I can't believe, even though it sat for 10 years, that a car with 32k miles on it would need a carb rebuild already.

Thanks, Paul

72 cutlass455

Many gaskets don't age well. After sitting 10 years a rebuild might help clean gunk and varnish from the carb. They have some types of jbweld that can stand the heat to fix the crack.

Lady72nRob71

Pretty uncommon...

77GCSX

Well, the "uncommon" has happened to me. I went investigating today and removed the EGR, "BOTH" pieces...uhhuh, it came off in two pieces. All I need now is a decent block off item and I think she'll run A LOT better. I can tell there is some leakage with my "whipped up in a couple minutes" block off because it still runs fantastic cold but once warmed up the hesitation is more noticeable.

I'm not against rebuilding the carb, as a matter of fact I just got the Rochester rebuild manual, I'm just trying the easy fixes first, mainly due to the down time that the Delta will have while I'm rebuilding. I say down time because it once took me 4 hours to put a wheel barrel together Rebuilding a carb is A LOT more involved then a garden tool.

Believe me, when I start rebuilding it, even WITH the manual, I'll be posting questions.

Allan R

I'm not sure your problem with running is related to the EGR. The EGR only functions at high vacuum like at startup and heavy accleration when at highway speeds. From what I have read your problem is more related to a warm engine. You might want to check your ported vacuum switch or see if you have a leak around the intake manifold.

You can block off the EGR. If you don't have a proper gasket, trace the outline on some construction paper and cutout 2 or 3 layers. Soak em in tranny fluid, press dry and it will form a good seal. I have the EGR blocked off on my 72 350 but will be reinstalling a working EGR when I rebuild it next spring. FWIW you can probably go to the wreckers and get a functional EGR for dirt cheap. Just take your old one as a reference. I think most of them have the same base.

MDchanic

What Allan said.

A leak in the EGR should not significantly affect running, especially if it is not otherwise noticeable.

All EGR is, is a controlled vacuum leak. Specifically, a leak of exhaust gasses (inert material) into the intake manifold. In the worst case, you would have air (oxygen) in place of the exhaust gasses. In practice, since the exhaust is under pressure, you'd need a pretty big leak to reduce the exhaust pressure to zero so that air could then be sucked in.

An EGR leak is usually noticed by it's noise. It sounds like an exhaust leak because it is an exhaust leak. If your EGR valve was quiet, then I doubt you had a leak of any significance.

I would replace the EGR (junkyard or auto parts store), and then look elsewhere for your problem.

- Eric

J-(Chicago)

I have one on a stock intake I could pull for you. $5 + ship