Home » Public Forums » GMCnet » GMC MOTORHOME POWER LOSS PROBLEM (STRICKEN FOR YEARS WITH POWER LOSS-ASKING FOR HELP)
| Re: [GMCnet] GMC MOTORHOME POWER LOSS PROBLEM [message #292208 is a reply to message #292194] |
Tue, 15 December 2015 15:19   |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
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> On Dec 15, 2015, at 12:58 PM, StanC wrote:
>
> HI KEN, THANKS FOR THE THOUGHTS.
>
> RIGHT NOW I AM OPEN TO ANYTHING.
>
> WE INSTALLED A SINGLE ELECTRIC FUEL PUMP ON THE RESERVE TANK WITH THE INTENTION OF USING IT FOR PRIMING THE VEHICLE. FOR THAT JOB, IT IS NOW EASY TO
> START HER UP.
>
> I ORIGINALLY SUGGESTED TWO PUMPS BUT SOMEONE SAID IT WOULDN'T WORK... APPARENTLY IT WASN'T YOU. LOL
>
> ON ONE OF OUR TEST DRIVES, WHEN THE POWER STARTED TO FLOUNDER, LOL I LIKE THAT WORD, IT STARTED TO FLOUNDER, WE HIT THE SWITCH FOR THE ELECTRIC PUMP.
> IT DIDN'T MATTER, NO DIFFERENCE AT ALL.
>
> THE MECHANIC HAS BEEN IN CONTACT WITH ONE OF OUR SUPPLIERS AND HE SAID HE WAS TOLD TO BLOW THE SOCKS OFF SO THEY ARE ALREADY GONE.
How do you know that they are gone? I blew 100 psi through my fuel lines once and I assumed that the socks were off — however, when I dropped the tanks to put in my in-tank fuel pumps I found that the socks were still firmly in place.
Emery Stora
>
> I AM GOING TO COPY ALL THESE COMMENTS AND PRINT THEM FOR THE MECHANIC. I WILL SUGGEST THE DUAL ELEC FUEL PUMP CONFIG. WE ARE PLANING TO DO THE
> PORTBLE GAS TANK FEED TEST. i THINK WE DID THIS LAST YEAR BUT I CAN'T REMEMBER NOW. WE HAVE DONE SO MUCH TO THIS THING THAT EVERYTHING IS RUNNING
> TOGETHER.
>
> THANKYOU SO MUCH FOR YOUR THOUGHTS
> I'LL SEE THE MECH LATER THIS WEEK AND WE WILL HAVE A GOOD TALK. I HAVE TO MOVE THE GMC HOME SOON, I AM RUNNING OUT OF SNOW FREE ROADS.
>
> THANKS AGAIN.
> SLC
>
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| Re: GMC MOTORHOME POWER LOSS PROBLEM [message #292210 is a reply to message #292162] |
Tue, 15 December 2015 15:36 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Rust comes from the tanks, the crossover line on the front crossmember, and the hard line from pump to carb. Water standing in any of these will produce rust. You've described an intermittent fuel supply, rust is often the cause. A new carb filter and a boat tank feeding it will prove or disprove the problem. I'll note, the crossover pipe is often overlooked when upgrading the system. It's steel, it will rust. It's at a low spot, water can collect in it. If it has rusted a pinhole, you'll also get power loss under load as air infiltrates.
In re Ken H's setup, I have someplace the pictures of mine. Mr Gasket pumps, which have integral check valves and come with filters. Throw the filters away and replace with the Wix replacement which doesn't loosen at the seams and let air in. Mount a relay, run a fused power line, and let the valve power pull the relay instead to supply fused power to the appropriate pump. Run the fused line through a turnover switch for safety - I got one off a early 2000s Ford Ranger cos it's easy to get, it's on the firewall just above the passenger toeboard inside the cab.
--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
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| Re: GMC MOTORHOME POWER LOSS PROBLEM [message #292215 is a reply to message #292162] |
Tue, 15 December 2015 15:43 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Found the pictures! No idea how they got in that folder, but........
http://www.gmcmhphotos.com/photos/cane-9-creek-rv-park-heflin-2c-al/p58467-fuel-pump-follies.html
They're 42 series Mr Gasket pumps, less than $50 on the net if you look. The relay is an automotive SPDT rated 30 amps, which is overkill, but it was like 4 bux in a blister pak at Advance. I pulled the power off the fused line switched by a relay from the ignition which also powers my suspension pump, through the turnover switch. That switch (Ranger) will also disconnect in the event of a shock such as a wreck. It will even disengage if, on a dark rainy night, you toss your shotgun case in the passenger seat and it whacks the shield over the switch. Ask me how I know this.
--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
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| Re: GMC MOTORHOME POWER LOSS PROBLEM [message #292217 is a reply to message #292162] |
Tue, 15 December 2015 15:53 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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The suggestion Ken made of the 2 electric pumps and no change over valve with new fuel lines is a good one. I did this to mine 2 years ago and haven't had vapor lock since but it should function the way you have it. The suggestion Sammy made is a possibility. I just rebuilt my 455 and was very careful to set the timing chain with the gear dots dead on at top dead center. The new engine idled good and cruised good but ran like crap on hills with lousy power. I replaced the spark plugs and put in my spare HEI no help. I figured it had to be the cam. I took the engine down to expose the chain and gears they were dead on. I bought a degree wheel at summit and a dial indicator at harbor freight to check the cam lobe center sure and enough the cam was retarded a full tooth . I moved the cam gear a tooth and rechecked the lobe center of the cam it was right on . I relucently put the engine covers back on with the dots on the cam gears 1/4" out of alignment it runs good now. The comp cam must have been made with the dowl pin a tooth retarded. So yes if your cam is off a tooth this is what you would expect.
Roy Keen
Minden,NV
76 X Glenbrook
[Updated on: Tue, 15 December 2015 15:55] Report message to a moderator |
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| Re: GMC MOTORHOME POWER LOSS PROBLEM [message #292222 is a reply to message #292162] |
Tue, 15 December 2015 16:10 |
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SeanKidd
Messages: 747
Registered: June 2012
Location: Northern Neck Virginia
Karma: 4
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I don't want to complicate things too much, but what year motorhome? Are you running electronic ignition, or a points type ignition? If running points, stop the presses and install a Patterson Electronic ignition, these are custom made for our low rpm engines. JimK or JimB can help you. If Previous owner upgraded to electronic from points, ensure it has 12v going to it, the original used a resistor wire that reduced the voltage to about 9V. I wish you the best of luck....don't give up!
Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.
Colonial Travelers
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| Re: [GMCnet] GMC MOTORHOME POWER LOSS PROBLEM [message #292225 is a reply to message #292222] |
Tue, 15 December 2015 16:36 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Keep in mind that the fuel filter is more like a strainer, so small
particulates will penitrate through the filter and build up.
Since you removed the sock filter, the filters your placing will load up
sooner.
We had one coach that took us three tries, and finally dropped the tank for
the second time as the ethanol did a nice job of washing down all the crud
in the tank which contaminated the selector valve.
Did not notice you replace the valve, but do so as the original has been
deteriorated .
Have you been in contact with Dave Marchiando?
He is in Sheridan, IL 815-695-5084 he is pretty sharp and does work on hem
and owns one as well.
Like everyone here says; don't hesitate to call us as that is what we do
all day as we know some things and know who the players that know more of
some area of the coach.
On Tue, Dec 15, 2015 at 2:10 PM, Sean Kidd wrote:
> I don't want to complicate things too much, but what year motorhome? Are
> you running electronic ignition, or a points type ignition? If running
> points, stop the presses and install a Patterson Electronic ignition,
> these are custom made for our low rpm engines. JimK or JimB can help you.
> If
> Previous owner upgraded to electronic from points, ensure it has 12v going
> to it, the original used a resistor wire that reduced the voltage to about
> 9V. I wish you the best of luck....don't give up!
> --
> Sean and Stephanie
> 73 Ex-CanyonLands 26' #317 "Oliver"
> Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD
> Honda 6500 inverter gen.
>
> Colonial Travelers
>
> _______________________________________________
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> Unsubscribe or Change List Options:
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>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: GMC MOTORHOME POWER LOSS PROBLEM [message #292251 is a reply to message #292162] |
Tue, 15 December 2015 19:56 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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847--- where are you? I'm in Woodstock and come into Chicago quite often. Sounds like a fun one to solve. I would have to hear and drive in it to see what was going on.
The only logical place the rust could be coming from is the fuel line between the rear filter and the engine pump.
Was the carb paper filter installed incorrectly to let rust into the carb?
My other guess is a restricted exhaust at this point. More common than you might think
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: GMC MOTORHOME POWER LOSS PROBLEM [message #292253 is a reply to message #292210] |
Tue, 15 December 2015 20:05 |
Gatsbys' Cruiser
Messages: 91
Registered: August 2014
Location: Illinois
Karma: 0
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Member |
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Rust comes from the tanks
THE INLINE FUEL FILTER JUST AFTER THE SOLENOID VALVES WAS PRISTINE, CLEAN. WE DISECTED IT TO MAKE SURE WE KNEW WHERE THE RUST CAME FROM. BY THAT SCENARIO ALONE, THE FUEL TANKS ARE CLEAN. WOULD YOU NOT AGREE?
THANK YOU FOR YOUR RESPONSE
YES, RUST CAN COME FROM THE TANKS, BUT NOT THIS TIME. NO RUST WAS PRESENT ON THE FILTER MATERIAL. FROM THE FILTER TO THE MECHANICAL FUEL PUMP IS ALL RUBBER HOSE. HOWEVER, THE INSIDE OF THE MECH FUEL PUMP WAS RUSTED SEVERLY. HOW DO I EXPLAIN THIS? THE CARB FLOAT BOWL WAS DRIPING INTERNALLY, AIR GOT INTO THE BOWL AND THE GAS DRAINED BACK TO THE TANK, I BELIEVE A COMBINATION OF THE ETHANOL AND MOISTURE IN THE AIR CAUSED THE INSIDE OF THE FUEL PUMP TO CORRODE.
WE SAWED OPEN THE MECH FUEL PUMP TO FIND THE SOURCE OF THE RUST, THE RUST CAME FROM THE FUEL PUMP.
WHERE IS THIS CROSS OVER PIPE? THE LINE FROM THE DISCHARGE OF THE MECH FUEL PUMP TO THE CARB IS RUBBER WITH EXCEPTION OF A PART BE BOUGHT FROM THE COOOP THAT CONNECTS TO THE CARB. I'M PRETTY SURE IT RUBBER BUT IT WILL BE THE FIRST THING i AM GOING TO LOOK FOR WHEN I GET THERE.
ken h'S setup
I CURRENTLY HAVE A SINGLE ELECTRIC FUEL PUMP OFF OF THE RESERVE TANK TO THE SOLENOID VALVE. A DESIGN SUGGESTED BY THE COOP. I HAVE QUITE A FEW SUGGESTIONS TO GO AFTER BEFORE I AM AT THE POINT OF ADDING MORE PUMPS AS THE FUEL SUPPLY MAY NOT BE THE PROBLEM. WHEN WE HAD A EXTERNAL TANK AND PUMP ON BEFORE, WE HAD THE SAME PROBLEM OCCUR, THIS WAS CONNECTED DIRECTLY TO THE CARB FILTER. WE DID THIS LAST YEAR OR SO BUT WILL BE DOING IT AGAIN.
THANKYOU
SLC
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| Re: [GMCnet] GMC MOTORHOME POWER LOSS PROBLEM [message #292261 is a reply to message #292260] |
Tue, 15 December 2015 21:06 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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A GMC dealer is dependent on the mechanic there.If nothing else call Dave
and see.
Your not going to be happy at a GMC Dealer a they hate working on old stuff.
As a last resort do that, OK.
On Tue, Dec 15, 2015 at 6:36 PM, StanC wrote:
> THANKYOU FOR YOUR RESPONSE
>
> 847--- where are you? I'm in Woodstock and come into Chicago quite often
> WAUKEGAN
>
> Sounds like a fun one to solve.
>
> GEE YOU HAVE A STRANGE SENCE OF FUN
>
> The only logical place the rust could be coming from is the fuel line
> between the rear filter and the engine pump.
>
> THE FUEL PUMP WAS SO RUSTY IT NO LONGER PUMPED. YOU BRING AN INTERESTING
> POINT THOUGH I AM NOTING IT ALSO.
>
> Was the carb paper filter installed incorrectly to let rust into the carb?
>
> THE FILTER IS NOT PAPER, IT IS GRANUALS PRESSED IN A CONE SHAPE. IT WAS
> INSTALLED CORRECTLY.
>
> My other guess is a restricted exhaust at this point. More common than you
> might think
>
> WOW, I DON'T KNOW. IT BELLOWS QUITE FREELY WHEN IDLING. LOL
>
> THANK YOU
> SLC
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] GMC MOTORHOME POWER LOSS PROBLEM [message #292264 is a reply to message #292261] |
Tue, 15 December 2015 21:18 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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You need the correct filter, the compressed metallic filter is ok, but it
does not do as much to capture the particulates as the current paper style
media has ten times more filter area and will last longer. Have not seen
those metallic filters since I was in college.
On Tue, Dec 15, 2015 at 7:06 PM, Jim Kanomata wrote:
> A GMC dealer is dependent on the mechanic there.If nothing else call Dave
> and see.
> Your not going to be happy at a GMC Dealer a they hate working on old
> stuff.
> As a last resort do that, OK.
>
> On Tue, Dec 15, 2015 at 6:36 PM, StanC wrote:
>
>> THANKYOU FOR YOUR RESPONSE
>>
>> 847--- where are you? I'm in Woodstock and come into Chicago quite often
>> WAUKEGAN
>>
>> Sounds like a fun one to solve.
>>
>> GEE YOU HAVE A STRANGE SENCE OF FUN
>>
>> The only logical place the rust could be coming from is the fuel line
>> between the rear filter and the engine pump.
>>
>> THE FUEL PUMP WAS SO RUSTY IT NO LONGER PUMPED. YOU BRING AN INTERESTING
>> POINT THOUGH I AM NOTING IT ALSO.
>>
>> Was the carb paper filter installed incorrectly to let rust into the carb?
>>
>> THE FILTER IS NOT PAPER, IT IS GRANUALS PRESSED IN A CONE SHAPE. IT WAS
>> INSTALLED CORRECTLY.
>>
>> My other guess is a restricted exhaust at this point. More common than
>> you might think
>>
>> WOW, I DON'T KNOW. IT BELLOWS QUITE FREELY WHEN IDLING. LOL
>>
>> THANK YOU
>> SLC
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Fremont,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] GMC MOTORHOME POWER LOSS PROBLEM [message #292278 is a reply to message #292277] |
Tue, 15 December 2015 23:36 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Brien,
Lot of us have had the module fool us making us thinking it is a faulty
carb starving, when in essence it was the module.
We have an analyzer, but at low rpm it will show no problem.
On Tue, Dec 15, 2015 at 9:19 PM, Brian Waddell
wrote:
> My advice...get rid of the stone filter...use the proper paper type filter
> for the carb and make sure it is is installed properly.
> Do you have a tachometer?.. If you have is the engine reving ,or is it
> cutting out or is it boging...need a tach.
> My motorhome has a rebuilt original engine, and new everything .
> including distributer....except the carb. The engine would start and idle
> perfect.
> As the rpm increased at a certain point in would fumble and drop revs and
> if I tied to make it rev up it would die.
> I played with that thing for months at every spare moment. I hired 2
> different mechanics . Both mechanis thought fuel. Carb apart many
> times...right carb for MH?...YEs...Everybody gave up on me ...the MH sat
> for 2 years because of this problem. Spoke to GNC carb experts...One day as
> I sat reving it, I notices a flicker in the test lite I had hooked
> up....This flicker led me to replace my new ignition module....End of
> problems...som of.........anyway I see your frustration....hope this
> helps....you will get you answer here...Brian 77 ele 455 winterpeg..or
> close enough
>
>> Date: Tue, 15 Dec 2015 19:36:00 -0700
>> To: gmclist@list.gmcnet.org
>> From: IceUniversity@inbox.com
>> Subject: Re: [GMCnet] GMC MOTORHOME POWER LOSS PROBLEM
>>
>> THANKYOU FOR YOUR RESPONSE
>>
>> 847--- where are you? I'm in Woodstock and come into Chicago quite often
>> WAUKEGAN
>>
>> Sounds like a fun one to solve.
>>
>> GEE YOU HAVE A STRANGE SENCE OF FUN
>>
>> The only logical place the rust could be coming from is the fuel line
> between the rear filter and the engine pump.
>>
>> THE FUEL PUMP WAS SO RUSTY IT NO LONGER PUMPED. YOU BRING AN
> INTERESTING POINT THOUGH I AM NOTING IT ALSO.
>>
>> Was the carb paper filter installed incorrectly to let rust into the
> carb?
>>
>> THE FILTER IS NOT PAPER, IT IS GRANUALS PRESSED IN A CONE SHAPE. IT WAS
> INSTALLED CORRECTLY.
>>
>> My other guess is a restricted exhaust at this point. More common than
> you might think
>>
>> WOW, I DON'T KNOW. IT BELLOWS QUITE FREELY WHEN IDLING. LOL
>>
>> THANK YOU
>> SLC
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
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
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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