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[GMCnet] Re: It was not a cracked intake- it was the carb. now what? [message #369247 is a reply to message #369245] Thu, 24 March 2022 21:54 Go to previous messageGo to previous message
CJV is currently offline  CJV   Canada
Messages: 49
Registered: December 2021
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Thank you....great info....

CJ Vermeulen, Scribbler


From: "jamesh1296"
To: "gmclist"
Sent: Thursday, March 24, 2022 9:00:28 PM
Subject: [GMCnet] Re: It was not a cracked intake- it was the carb. now what?

There are two kinds of cast iron manifolds. Those that are cracked, and
those that haven't cracked yet. If the cracks are accessible from the
bottom, a hole can be drilled at each end of the crack, "V" ing out the
crack with a die grinder, then tig welding the crack with rod intended for
cast iron repair. Or, use the same prep and use bronze brazing rod. When
you finish, then block off the crossover with stainless steel plates
between the heads and manifold. Some have filled the crossover passage with
poured molten aluminum or other metals. I have not done either of these
methods, but I have practiced on a severely cracked manifold.
If the manifold is cracked through to the intake passages under the
carb, it is tough sledding to get effective welds in there.
Jim Hupy
Salem, Oregon

On Thu, Mar 24, 2022, 6:32 PM CJV wrote:



Is there any way to satisfactorily repair a cracked manifold?

CJ Vermeulen, Scribbler


From: "Len Novak"
To: "dave silva" , "gmclist"
Sent: Thursday, March 24, 2022 6:20:48 PM
Subject: [GMCnet] Re: It was not a cracked intake- it was the carb. now
what?

Just for grins look for a crack at the base of the carb. Been there,
done that. Took forever to find that.


Len Novak



On 3/24/2022 4:15 PM, dave silva wrote:


This coach had been fully rebuilt and then parked for seven years when i
got it.

This made it hard to troubleshoot. It would run OK and then bog down. So
of course we looked at fuel lines, filters, old gas etc.

Got all that sorted still no change. Chased vac leaks etc. No change.

Then someone suggested a cracked intake- that fit the symptoms perfectly.
The issue would get worse as the engine warmed up but also, the severity
would get worse over time. So it made perfect sense that a crack would
open more as the engine wormed and get bigger over time.

I scored a good intake and commenced to changing it. And when it was all
back together there is NO CHANGEit still does not run right.

So maybe the carb? The Revcon is sitting there, has not been run in over a
year. The original Toronado Carb has NEVER been rebuilt, but i swap it
out and the Coach runs PERFECTLY!

Ok, that was a long and winding road. Whatever is going on is happening in
the carb ONLY.


Here's the symptoms- engine starts pretty easily, takes off smoothly and
accelerates into second gear and then has no more power. If I give it more
gas is bogs down like it's gonna stall.

This gets worse the longer i drive it (lately not more than a couple
miles)

This carb was freshly rebuilt for the Coop in 2013. it went 1000 miles and
did not move again so I'm not inclined to tear in all apart, it's not like
parts are worn or thousands of gallons of fuel have run through it.

What Say the Brain Trust ?
















--
Len and Pat Novak 1978 GMC Kingsley The Beast II with dash lights that
work and labels you can see! Las Vegas, NV new email: B52srule@gmail.com
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
www.bdub.net/novak/
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