Clasco is now homed in AK

J

jerry work

New member
Feb 3, 2003
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The people who purchased our Clasco made it back to AK without further incident. I never did learn what they found caused the no start issue at the gas station south of Denver. I had installed that FiTech fuel injection so one could revert back to a carb in less than a half hour without getting under the coach but at the time he seemed reluctant to do that. He apparently finally did as he reported it started up immediately once he did reinstall the carb stored in the pod

I am curious as to what may have gone wrong, if anything, with the FiTech throttle body or the fuel management system that could have caused the no start. He indicated he was seeing or hearing the initial key-on squirt of fuel but it would not keep running. He also indicated both the high pressure and low pressure fuel gauges were reporting proper readings. He had been driving in extremes of heat and altitude but the no start occurred many hundreds of miles further on

We plan to revisit AK next summer in the Prevost so will inquire further then if we see them. Our extended shake down cruise in the Prevost is going splendidly so far. All systems are go with not even minor things to record or fix. Just a vault like driving experience that makes this the easiest to drive and maneuver and most relaxed coach I have ever driven. Sleeps well, too! (Grin)

Jerry

Jerry Work
Kerby, OR
 
When electronic devices overheat they do bad things including complete failure. The FiTech unit is a neat integrated package but I question the
reliability of electronics sitting directly on top of an engine, especially an engine that is known to get really hot on top. If it gets hot enough to
discolor paint on the intake it probably gets hot enough to cause electronics to malfunction.

Maybe the FiTech on the Clasco worked fine as long as the engine was running, the airflow over and through the unit kept it cool enough. When the
owner stopped for fuel he had probably been cruising down the freeway and pulled into the nearest gas station and immediately shut off the engine.
Heat soaking the FiTech may have been what killed it. I would bet the FiTech got very hot with the airflow suddenly removed and it just failed due to
high temps.

Just a guess.


--
Bob Heller
1974 X-Canyonlands 26ft
Original 455 exc for timing chain,
Rockwell intake, valve covers. 141k miles.
Winter Springs FL
 
Bob,
I need to agree with you.
Both MSD an FiTech and other units were never designed to put up with the
environment our coaches with low hood and big exhaust crossover.
I suggest that one should use the intake block off plate.
Should that unit not be covered by warranty, call me so I can get it
covered.

> When electronic devices overheat they do bad things including complete
> failure. The FiTech unit is a neat integrated package but I question the
> reliability of electronics sitting directly on top of an engine,
> especially an engine that is known to get really hot on top. If it gets hot
> enough to
> discolor paint on the intake it probably gets hot enough to cause
> electronics to malfunction.
>
> Maybe the FiTech on the Clasco worked fine as long as the engine was
> running, the airflow over and through the unit kept it cool enough. When the
> owner stopped for fuel he had probably been cruising down the freeway and
> pulled into the nearest gas station and immediately shut off the engine.
> Heat soaking the FiTech may have been what killed it. I would bet the
> FiTech got very hot with the airflow suddenly removed and it just failed
> due to
> high temps.
>
> Just a guess.
>
>
> --
> Bob Heller
> 1974 X-Canyonlands 26ft
> Original 455 exc for timing chain,
> Rockwell intake, valve covers. 141k miles.
> Winter Springs FL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
Jim, good point. I think that is why our Howell units still run well as all the electronics are remote mounted. I have my ECU under the passenger seat and just by itself it gets pretty warm. Can’t imagine how it would do on top of the engine.

>
> Bob,
> I need to agree with you.
> Both MSD an FiTech and other units were never designed to put up with the
> environment our coaches with low hood and big exhaust crossover.
> I suggest that one should use the intake block off plate.
> Should that unit not be covered by warranty, call me so I can get it
> covered.
>
>

>
>> When electronic devices overheat they do bad things including complete
>> failure. The FiTech unit is a neat integrated package but I question the
>> reliability of electronics sitting directly on top of an engine,
>> especially an engine that is known to get really hot on top. If it gets hot
>> enough to
>> discolor paint on the intake it probably gets hot enough to cause
>> electronics to malfunction.
>>
>> Maybe the FiTech on the Clasco worked fine as long as the engine was
>> running, the airflow over and through the unit kept it cool enough. When the
>> owner stopped for fuel he had probably been cruising down the freeway and
>> pulled into the nearest gas station and immediately shut off the engine.
>> Heat soaking the FiTech may have been what killed it. I would bet the
>> FiTech got very hot with the airflow suddenly removed and it just failed
>> due to
>> high temps.
>>
>> Just a guess.
>>
>>
>> --
>> Bob Heller
>> 1974 X-Canyonlands 26ft
>> Original 455 exc for timing chain,
>> Rockwell intake, valve covers. 141k miles.
>> Winter Springs FL
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Gary Worobec
garytwmw
(o) 951-763-0518
(cell) 773-230-6226
 
Mention EFI, people who are not really knowledgeable of the latest
development think these MSD, Fi Tech are the way to go on the Motorhome.
Lot of us that are up to date know that these lesser units are not going to
give you much more than a fine running carburetor.
Our Howell based unit with the EBL computer option gives you what a real
EFI should.
Yes, you do not need to program our units as they come from us ready to run.

> Jim, good point. I think that is why our Howell units still run well as
> all the electronics are remote mounted. I have my ECU under the passenger
> seat and just by itself it gets pretty warm. Can’t imagine how it would do
> on top of the engine.
>
>

> >
> > Bob,
> > I need to agree with you.
> > Both MSD an FiTech and other units were never designed to put up with
> the
> > environment our coaches with low hood and big exhaust crossover.
> > I suggest that one should use the intake block off plate.
> > Should that unit not be covered by warranty, call me so I can get it
> > covered.
> >
> >

> >
> >> When electronic devices overheat they do bad things including complete
> >> failure. The FiTech unit is a neat integrated package but I question the
> >> reliability of electronics sitting directly on top of an engine,
> >> especially an engine that is known to get really hot on top. If it gets
> hot
> >> enough to
> >> discolor paint on the intake it probably gets hot enough to cause
> >> electronics to malfunction.
> >>
> >> Maybe the FiTech on the Clasco worked fine as long as the engine was
> >> running, the airflow over and through the unit kept it cool enough.
> When the
> >> owner stopped for fuel he had probably been cruising down the freeway
> and
> >> pulled into the nearest gas station and immediately shut off the engine.
> >> Heat soaking the FiTech may have been what killed it. I would bet the
> >> FiTech got very hot with the airflow suddenly removed and it just failed
> >> due to
> >> high temps.
> >>
> >> Just a guess.
> >>
> >>
> >> --
> >> Bob Heller
> >> 1974 X-Canyonlands 26ft
> >> Original 455 exc for timing chain,
> >> Rockwell intake, valve covers. 141k miles.
> >> Winter Springs FL
> >>
> >> _______________________________________________
> >> GMCnet mailing list
> >> Unsubscribe or Change List Options:
> >> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >>
> >
> >
> >
> > --
> > Jim Kanomata
> > Applied/GMC, Newark,CA
> > jimk
> > http://www.appliedgmc.com
> > 1-800-752-7502
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> Gary Worobec
> garytwmw
> (o) 951-763-0518
> (cell) 773-230-6226
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
Point well taken on having electronic components as far removed from engine
heat as possible. The top of a 455 or 403 near the exhaust crossover gets
hot enough to melt plug wires, vacuum hoses, wire insulation, and engine
enamel. GMC Motor home engine compartments are a hostile environment.
I know that Fi-tec says that their electronics can stand engine heat,
but with the drop center design of the intake manifold on the Olds engines
combined with the exhaust crossover, it can't do them any favors. Like
Jerry, I would want to send the failed unit to Fi-tec to see what they
find. Be nice if there were built in diagnostics in their ECM that would
check heat related failures.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> Mention EFI, people who are not really knowledgeable of the latest
> development think these MSD, Fi Tech are the way to go on the Motorhome.
> Lot of us that are up to date know that these lesser units are not going to
> give you much more than a fine running carburetor.
> Our Howell based unit with the EBL computer option gives you what a real
> EFI should.
> Yes, you do not need to program our units as they come from us ready to
> run.
>

>
> > Jim, good point. I think that is why our Howell units still run well as
> > all the electronics are remote mounted. I have my ECU under the passenger
> > seat and just by itself it gets pretty warm. Can’t imagine how it would
> do
> > on top of the engine.
> >
> >
> > > On Jun 15, 2017, at 9:09 AM, Jim Kanomata

> > >
> > > Bob,
> > > I need to agree with you.
> > > Both MSD an FiTech and other units were never designed to put up with
> > the
> > > environment our coaches with low hood and big exhaust crossover.
> > > I suggest that one should use the intake block off plate.
> > > Should that unit not be covered by warranty, call me so I can get it
> > > covered.
> > >
> > >
> > > On Thu, Jun 15, 2017 at 7:06 AM, Bob Heller

> > >
> > >> When electronic devices overheat they do bad things including complete
> > >> failure. The FiTech unit is a neat integrated package but I question
> the
> > >> reliability of electronics sitting directly on top of an engine,
> > >> especially an engine that is known to get really hot on top. If it
> gets
> > hot
> > >> enough to
> > >> discolor paint on the intake it probably gets hot enough to cause
> > >> electronics to malfunction.
> > >>
> > >> Maybe the FiTech on the Clasco worked fine as long as the engine was
> > >> running, the airflow over and through the unit kept it cool enough.
> > When the
> > >> owner stopped for fuel he had probably been cruising down the freeway
> > and
> > >> pulled into the nearest gas station and immediately shut off the
> engine.
> > >> Heat soaking the FiTech may have been what killed it. I would bet the
> > >> FiTech got very hot with the airflow suddenly removed and it just
> failed
> > >> due to
> > >> high temps.
> > >>
> > >> Just a guess.
> > >>
> > >>
> > >> --
> > >> Bob Heller
> > >> 1974 X-Canyonlands 26ft
> > >> Original 455 exc for timing chain,
> > >> Rockwell intake, valve covers. 141k miles.
> > >> Winter Springs FL
> > >>
> > >> _______________________________________________
> > >> GMCnet mailing list
> > >> Unsubscribe or Change List Options:
> > >> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> > >>
> > >
> > >
> > >
> > > --
> > > Jim Kanomata
> > > Applied/GMC, Newark,CA
> > > jimk
> > > http://www.appliedgmc.com
> > > 1-800-752-7502
> > > _______________________________________________
> > > GMCnet mailing list
> > > Unsubscribe or Change List Options:
> > > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> > Gary Worobec
> > garytwmw
> > (o) 951-763-0518
> > (cell) 773-230-6226
> >
> >
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Semiconductors are temperature rated for the the intended application (consumer, commercial, industrial, automotive or extended & Military/aerospace).
Automotive (extended) rating is the highest (-40 to 125C) next to Military/aerospace. The higher the rating, the higher the cost (military/aerospace
is exponentially higher in cost). The 125C rating of the automotive rating is the ambient temperature of its surroundings, the internal temperature of
the component is running much hotter. The semiconductor itself generates heat which must be moved to the exterior of the chip to be cooled. The there
is a thermal resistance between the semiconductor die and the case and then to the surrounding air to cool it. Plus there are other components around
it generating heat which also needs to be dissipated. This raises the internal temperature of the board itself above the ambient temperature around
the throttle body. Heat also shortens the life of all the components, especially electrolytic capacitors.

When you are moving down the road you have lots of cooling air plus the evaporation of the fuel cools the throttle body. When you stop the engine, I
can imagine the air temperature from the exhaust manifold can raise the temperature above the engine significantly above 125C.

There is good reason electronics are not normally mounted where there is significant heat.

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
Hubler 1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
 
Bob,
I need to agree with you.
Both MSD an FiTech and other units were never designed to put up with the
environment our coaches with low hood and big exhaust crossover.
I suggest that one should use the intake block off plate.
Should that unit not be covered by warranty, call me so I can get it
covered.
......,
 
IIRC, the FiTec sits on top of an alum spacer/adapter and conducting heat to the efi.
would it help if the spacer was made of thermo insulating material? Like carbs have.
I always let the engine idle a few minutes after a fast run to reduce the heat soak at shut off.
A slow drive through a camp ground will do the same thing.

Thinking about FiTec vs GM TBI.

> When electronic devices overheat they do bad things including complete failure. The FiTech unit is a neat integrated package but I question the
> reliability of electronics sitting directly on top of an engine, especially an engine that is known to get really hot on top. If it gets hot enough
> to discolor paint on the intake it probably gets hot enough to cause electronics to malfunction.
>
> Maybe the FiTech on the Clasco worked fine as long as the engine was running, the airflow over and through the unit kept it cool enough. When the
> owner stopped for fuel he had probably been cruising down the freeway and pulled into the nearest gas station and immediately shut off the engine.
> Heat soaking the FiTech may have been what killed it. I would bet the FiTech got very hot with the airflow suddenly removed and it just failed due
> to high temps.
>
> Just a guess.

--
”When we avoid the mistakes we might have made, we sometimes make the mistakes that we might have avoided.”

Adrien & Jenny Genesoto
75 Glenbrook 26-3
Yuba City,Ca. Text 530-nine-3-three-3-nine-nine-6
 
G'day,

Seems to me that someone who has a Fitech, MSD, or whatever, should call the
respective manufacturers and find out what the design temp range for the
electronics was.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
 
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