[GMCnet] For the carb guys and/or the part fitment gooroos

[6cuda6--- via Gmclist]

After i ran out of time playing roof AC redesign today i changed gears and started tackling the stumble/almost stall on initial throttle application.


First order of business was to replace as many bad vacuum lines as i could see....2 more to go...the ones to/from the vacuum control solenoid. {i'm
not sure who pissed of that Olds 403 emission engineer but he should try changing the 2 vacuum lines behind the power steering pump filler neck}. Next
was to look/test all the vacuum actuators....you guessed it the throttle lever actuator or throttle pusher as the parts manual calls it....seized
solid.

So the question for today.... does anyone know the part number for a new one? [ps: i'm not really a jamb the BB in the vacuum hose kinda guy but i
will if this little gem of an actuator turns into the most collectible piece of GMC history]
--
Rich Mondor,

Brockville, ON

77 Hughes 2600

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[Matt Colie via Gmclist]

I can (unfortunately) tell you how it ended up like that..

After some poor dyno jock finished doing a map of spark and fuel loops, somebody looked at the data and said "we can't have this - fix it." That
meant push off the performance part of the map into a better emissions part of the map. That was a what ever it took effort. You would not believe
some of the cheap tricks that were tried. The one I always admired was holding the advance curve back in the lower gears so the extra heat would get
the catalyst lit. Another good one used to be keeping the engine near stoch (stoichiometric - ideal) but making alternate between rich and lean to
keep the cat hot.

Great times they were - NOT

Matt - the refugee from dynoland
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

[James Hupy via Gmclist]

Try being a tech working in the trade, trying to make sense of all that
stuff like spark retard where there once was advance, and vacuum there when
the engine was pulling hard and there should not have been any, and hoses
galore, and the beat goes on, the beat goes on.
Jim Hupy
Salem, Oregon

On Sun, May 3, 2020, 4:38 PM Matt Colie via Gmclist <gmc...@list.gmcnet.org>
wrote:

[Charles Boyd via Gmclist]

Sir, you do know that throttle pusher is only active with the engine running and gear shifter in Drive?





6cuda6 wrote on Sun, 03 May 2020 19:07

> After i ran out of time playing roof AC redesign today i changed gears and started tackling the stumble/almost stall on initial throttle
> application.
>
> First order of business was to replace as many bad vacuum lines as i could see....2 more to go...the ones to/from the vacuum control solenoid.
> {i'm not sure who pissed of that Olds 403 emission engineer but he should try changing the 2 vacuum lines behind the power steering pump filler
> neck}. Next was to look/test all the vacuum actuators....you guessed it the throttle lever actuator or throttle pusher as the parts manual calls
> it....seized solid.
>
> So the question for today.... does anyone know the part number for a new one? [ps: i'm not really a jamb the BB in the vacuum hose kinda guy but i
> will if this little gem of an actuator turns into the most collectible piece of GMC history]


--

C. Boyd
76 Crestmont
East Tennessee

[6cuda6--- via Gmclist]

I do Mr Boyd..thanks for the reminder...mine is seized solid.

C Boyd wrote on Sun, 03 May 2020 19:46

> Sir, you do know that throttle pusher is only active with the engine running and gear shifter in Drive?
>
>
>
>
>
> 6cuda6 wrote on Sun, 03 May 2020 19:07
> > After i ran out of time playing roof AC redesign today i changed gears and started tackling the stumble/almost stall on initial throttle
> > application.
> >
> > First order of business was to replace as many bad vacuum lines as i could see....2 more to go...the ones to/from the vacuum control solenoid.
> > {i'm not sure who pissed of that Olds 403 emission engineer but he should try changing the 2 vacuum lines behind the power steering pump filler
> > neck}. Next was to look/test all the vacuum actuators....you guessed it the throttle lever actuator or throttle pusher as the parts manual calls
> > it....seized solid.
> >
> > So the question for today.... does anyone know the part number for a new one? [ps: i'm not really a jamb the BB in the vacuum hose kinda guy
> > but i will if this little gem of an actuator turns into the most collectible piece of GMC history]


--

Rich Mondor,

Brockville, ON

77 Hughes 2600

[6cuda6--- via Gmclist]

I know it all to well Jim....GM main line tech form 1984 to 1994...yup saw it in the heyday of carbs, vacuum lines, converters, air pumps, into
throttle body injection, tuned port injection you name it....when the wife said she wanted a GMC it was both a high and a low because i knew the
engine would be simple to keep running but i also knew the downfalls to 40 plus years of people messing with it.

James Hupy wrote on Sun, 03 May 2020 19:49

> Try being a tech working in the trade, trying to make sense of all that
> stuff like spark retard where there once was advance, and vacuum there when
> the engine was pulling hard and there should not have been any, and hoses
> galore, and the beat goes on, the beat goes on.
> Jim Hupy
> Salem, Oregon
>
> On Sun, May 3, 2020, 4:38 PM Matt Colie via Gmclist

--
Rich Mondor,

Brockville, ON

77 Hughes 2600

[6cuda6--- via Gmclist]

I think the best ever was Cadillac's 1986 4-6-8 engine.... one of the few cars i never wanted to work on and didnt care what they wanted to pay us...i
know a few techs that would have liked to hang the engineers that designed that thing.....lol.

Matt Colie wrote on Sun, 03 May 2020 19:38

> I can (unfortunately) tell you how it ended up like that..
>
> After some poor dyno jock finished doing a map of spark and fuel loops, somebody looked at the data and said "we can't have this - fix it." That
> meant push off the performance part of the map into a better emissions part of the map. That was a what ever it took effort. You would not believe
> some of the cheap tricks that were tried. The one I always admired was holding the advance curve back in the lower gears so the extra heat would
> get the catalyst lit. Another good one used to be keeping the engine near stoch (stoichiometric - ideal) but making alternate between rich and lean
> to keep the cat hot.
>
> Great times they were - NOT
>
> Matt - the refugee from dynoland


--

Rich Mondor,

Brockville, ON

77 Hughes 2600

[Charles Boyd via Gmclist]

Sir, I thought the 4,6,8 engine was started in 1981 with the trunk less Seville? Anyway as a side note.. the last 403 I worked on with a flat spot
off idle ended up being a bad carb gasket under the top plate. I took it off to inspect and replace accelerator pump. It was at the GMCMI rally in
Tallahassee. Jim Bounds had a used carb he gave me for parts and I salvaged the pump and gasket. Most people remove that idle pusher and the vacuum
valve on the front of the pass head and the solenoid on the front of the drivers head, but being OCD ( old, cranky, dyslexics ) I put it back on.



6cuda6 wrote on Sun, 03 May 2020 20:30

> I think the best ever was Cadillac's 1986 4-6-8 engine.... one of the few cars i never wanted to work on and didnt care what they wanted to pay
> us...i know a few techs that would have liked to hang the engineers that designed that thing.....lol.
>
> Matt Colie wrote on Sun, 03 May 2020 19:38
> > I can (unfortunately) tell you how it ended up like that..
> >
> > After some poor dyno jock finished doing a map of spark and fuel loops, somebody looked at the data and said "we can't have this - fix it."
> > That meant push off the performance part of the map into a better emissions part of the map. That was a what ever it took effort. You would not
> > believe some of the cheap tricks that were tried. The one I always admired was holding the advance curve back in the lower gears so the extra
> > heat would get the catalyst lit. Another good one used to be keeping the engine near stoch (stoichiometric - ideal) but making alternate between
> > rich and lean to keep the cat hot.
> >
> > Great times they were - NOT
> >
> > Matt - the refugee from dynoland


--

C. Boyd
76 Crestmont
East Tennessee

[6cuda6--- via Gmclist]

I have a carb rebuild kit sitting here waiting to go....its coming off in the hear future....after i finish the roof AC swap....after i drop the
tanks...after i get the exhaust eelded up for the generator....after..... lol. In the mean time it runs and moves.

C Boyd wrote on Sun, 03 May 2020 21:30

> Sir, I thought the 4,6,8 engine was started in 1981 with the trunk less Seville? Anyway as a side note.. the last 403 I worked on with a flat
> spot off idle ended up being a bad carb gasket under the top plate. I took it off to inspect and replace accelerator pump. It was at the GMCMI
> rally in Tallahassee. Jim Bounds had a used carb he gave me for parts and I salvaged the pump and gasket. Most people remove that idle pusher and
> the vacuum valve on the front of the pass head and the solenoid on the front of the drivers head, but being OCD ( old, cranky, dyslexics ) I put it
> back on.
>
>
>
> 6cuda6 wrote on Sun, 03 May 2020 20:30
> > I think the best ever was Cadillac's 1986 4-6-8 engine.... one of the few cars i never wanted to work on and didnt care what they wanted to
> > pay us...i know a few techs that would have liked to hang the engineers that designed that thing.....lol.
> >
> > Matt Colie wrote on Sun, 03 May 2020 19:38
> > > I can (unfortunately) tell you how it ended up like that..
> > >
> > > After some poor dyno jock finished doing a map of spark and fuel loops, somebody looked at the data and said "we can't have this - fix
> > > it." That meant push off the performance part of the map into a better emissions part of the map. That was a what ever it took effort. You
> > > would not believe some of the cheap tricks that were tried. The one I always admired was holding the advance curve back in the lower gears so
> > > the extra heat would get the catalyst lit. Another good one used to be keeping the engine near stoch (stoichiometric - ideal) but making
> > > alternate between rich and lean to keep the cat hot.
> > >
> > > Great times they were - NOT
> > >
> > > Matt - the refugee from dynoland


--

Rich Mondor,

Brockville, ON

77 Hughes 2600

[Dave King via Gmclist]

So I have a SOB, 1977 on a Dodge chassis with a heavy duty Dodge 440
I've had the top end of the motor apart. The only emissions stuff I see is
Crankcase (valve cover) breather is into the air cleaner. I HAVEN't found a
PCV valve. The coach was built by Champion. An y idea why it doesn't have
Emmissions stuff? Perhaps it was classed as a truck ??
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada

[Carl Stouffer via Gmclist]

kingd wrote on Mon, 04 May 2020 19:08

> So I have a SOB, 1977 on a Dodge chassis with a heavy duty Dodge 440
> I've had the top end of the motor apart. The only emissions stuff I see is
> Crankcase (valve cover) breather is into the air cleaner. I HAVEN't found a
> PCV valve. The coach was built by Champion. An y idea why it doesn't have
> Emmissions stuff? Perhaps it was classed as a truck ??

Dave,

It probably was not required to have (much) emissions equipment on it due to the GVW Rating.

I had an '80 Dodge 300 (1-ton) with a 10,000# GVW rating that ran on leaded regular gas, no catalytic converters. It had a 360 engine in it, not a
440, and the only emission equipment it had on it was an air pump system (and a PCV Valve).. I'm surprised yours doesn't al least have a PCV valve,
but the GVW is the only reason I can think of as to why.

--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

[roy keen via Gmclist]

A 1977 champion motor home with a 440 should have a PCV valve unless someone removed it. Does it have a draft tube? It shouldn’t have one.

--
Roy Keen
Minden,NV
76 X Glenbrook

[John R. Lebetski via Gmclist]

A lot of emissions stuff gets bad rapped because of lack of knowledge and people say “rip that s$& out”. The TCS Transmission Controlled Spark is
about the only system I defeated on my 70 GS. Robbed power and economy in 1st and second gear. Most of the other systems were wonderful with only up
sides TVS no down side. Charcoal evap system is brilliant. Heat riser system on pass cars (when working) brilliant! PCV huge improvement over road
draft tube. Early EGR (1973) was a bit invasive to drivability but by OBD1 was invisible to the driver feel. Luckily not GMC due to GVW. The small
block Olds stuff have a vacuum diagram that looked like an Esher drawing.
If you can’t find the throttle control part, I’d suggest a simple 60-70s GM dashpot damper to delay and cushion the last few degrees of throttle
closure.
--
John Lebetski
Woodstock, IL
77 Eleganza II

[Johnny Bridges via Gmclist]

I have an 85 pickup with OBD1. Very littl;e information can I find on it, even in the shop manual, which is Haynes, not Ford. However, I do have an
older distributor and rebuildable carb so at some point reverting to pre OBD setup is in the future. Right now, it all works becausethe PO knew what
he was doing. (Thaqbnks, Dave). So there's no ruish.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

[James Hupy via Gmclist]

Two of those systems were issues, because they were poorly thought out, and
made of materials unsuitable for the task.
One was the intake manifold mounted egr valve located in the exhaust
crossover. Took considerable maintenance to make it keep working as it was
supposed to.
The second was the vane type air pump without an air cleaner that blew
(injected) air into the exhaust manifolds via tubing better suited for a
task like a vacuum line. Let's see, steel, + exhaust heat + lots of oxygen
= the components needed for a welding torch. Those lines did not live long
in that environment, the manifolds blew gaskets, cracked, became impossible
to remove the bolts out of, etc. A service nightmare. All to dilute the UHC
stream to pass emissions. The distributor retard stuff that was applied
only in the lower gears was interesting, too.
Ah yes, the good old 70's. Didn't like bell bottomed pants much either. Or
disco Donna Summer. Bob Wills is still the King. Asleep at the wheel played
in my shop.
Jim Hupy
Salem, Oregon

[Jim Kanomata via Gmclist]

I agree with John.
I do not understand All the emission accessory , but know what most do and
how it does it cut on pervfotrmance.
Lot of misunderstanding.
Being in California, our standards are high, but find the 455 and 403 have
no issues if you know what is going on.

--
Jim Kanomata
Applied/GMC, Newark,CA
ji...@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502

[6cuda6--- via Gmclist]

Yup i know what they do a well hence the part # request for the throttle pusher as GMC called it. As Johnny said worse case ill find something from a
Chev motor that will work as they all did the same thing.

[Dave King via Gmclist]

Does any one have data regarding emissions requirements for 1977 by GVW?
I'm trying to understand why my SOB has so little emissions stuff compared to
what I think I'm reading people have on their GMCMH. I know in the now
discontinued smog testing in Ontario my MH was NOT required to be
tested. I doubt that Dodge could have guessed that the completed coach
would end up in Canada

--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada

[6cuda6--- via Gmclist]

There are 3 versions of the emission set ups....one for the 403, one for 455 and then the same for California only.

Alot of truck were exempt because they may have been classed at commercial....i also had a 1986 Ford truck with no emisdion controls because it was
ordered as a Farm Exempt truck.

kingd wrote on Tue, 05 May 2020 20:02

> Does any one have data regarding emissions requirements for 1977 by GVW?
> I'm trying to understand why my SOB has so little emissions stuff compared to
> what I think I'm reading people have on their GMCMH. I know in the now
> discontinued smog testing in Ontario my MH was NOT required to be
> tested. I doubt that Dodge could have guessed that the completed coach
> would end up in Canada


--

Rich Mondor,

Brockville, ON

77 Hughes 2600

[John R. Lebetski via Gmclist]

James, I worked with Donna Summers doing sound several times. She was a very warm person. She threw a heck of a party for us at Harrah’s private
house in Tahoe on the lake on a day off. Not a disco guy either here but love Jimmy Webb. And found her version more tolerable of that song. And
dummy me, I completely forgot to mention A.I.R. I found most trouble free but always disliked that sound through the diverter valve muffler.

--
John Lebetski
Woodstock, IL
77 Eleganza II

[Jerry Burt via Gmclist]

6cuda6 - Here is a PDF by Bob Drewes that gives you a complete breakdown of all the GMC quadrajets and changes through the years.
http://www.bdub.net/Quadrajets_in_GMCs.pdf
Probably more info than you want but...

This and many more links can be found at:
http://www.bdub.net/oddsnends.html
This is a handy page to bookmark as it has many links, in one place, that we normally have to hunt for on the various club pages.
I don't know who put the page together ?Billy? but thanks.
--
Patti & Jerry Burt Fresno, CA.
73 Gmc 26' Canyon Lands
77 Palm Beach - Parts Coach - SOLD
Members: FMCA - GMCMI - GMCWS
A truly happy person is one who can enjoy the scenery on a detour.

[Charles Boyd via Gmclist]

Sir, after re-reading my reply it looks like I was taking credit for repairing Jim’s carb at Tallahassee. I did take it off and chase tools and
parts but it was Hubert Rowell that did his carburetor magic that he does so well..

[quote title=C Boyd wrote on Sun, 03 May 2020 21:30]Sir, I thought the 4,6,8 engine was started in 1981 with the trunk less Seville? Anyway as a side

note.. the last 403 I worked on with a flat spot off idle ended up being a bad carb gasket under the top plate. I took it off to inspect and replace
accelerator pump. It was at the GMCMI rally in Tallahassee. Jim Bounds had a used carb he gave me for parts and I salvaged the pump and gasket.
Most people remove that idle pusher and the vacuum valve on the front of the pass head and the solenoid on the front of the drivers head, but being
OCD ( old, cranky, dyslexics ) I put it back on.

6cuda6 wrote on Sun, 03 May 2020 20:30
> I think the best ever was Cadillac's 1986 4-6-8 engine.... one of the few cars i never wanted to work on and didnt care what they wanted to pay
> us...i know a few techs that would have liked to hang the engineers that designed that thing.....lol.
>
> Matt Colie wrote on Sun, 03 May 2020 19:38
> > I can (unfortunately) tell you how it ended up like that..
> >
> > After some poor dyno jock finished doing a map of spark and fuel loops, somebody looked at the data and said "we can't have this - fix it."
> > That meant push off the performance part of the map into a better emissions part of the map. That was a what ever it took effort. You would not
> > believe some of the cheap tricks that were tried. The one I always admired was holding the advance curve back in the lower gears so the extra
> > heat would get the catalyst lit. Another good one used to be keeping the engine near stoch (stoichiometric - ideal) but making alternate between
> > rich and lean to keep the cat hot.
> >
> > Great times they were - NOT
> >
> > Matt - the refugee from dynoland

[/quote]