As my jouney continues.... That frikken power loss problem on Gatsbys' Cruiser

S

slc

New member
Jan 24, 2017
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First, I am most appreciative to all of you that have offered ideas to find this 10 year long search. I know how long it has been because that is
when I bought the tires and aluminumum wheels and had the fuel lines replaced, which of course required dropping the fuel tanks.

The power loss problem has persisted since, all this time as we searched, repaired, replaced and continued to test. I am thankful that I have at
least been able to start the GMC so it isn't really a forgotten derelict. I always shutter when I hear stories about those GMC motorhomes. As my
mechanic likes to repeat, vehicles do not get better sitting and rusting.

So most of all of the accessories and some engine parts are new. Parts of the fuel line from the solenoid, to and including the Mechanical fuel pump
are all new. Running the test connected to the normal fuel system, the power loss at 45mph is there.

We finally made an effort to use the external gas can. This can be involved also now that the mechanical fuel pump has a return fuel line. unless
that return line feeds to the external gas can, you won't have a very long run time.

Testing with the external fuel can was SUCCESSFUL!! I took her down the highway on 3 different occasions doing 75mph and she still wanted to go
faster. The problem has to be the lines to the tanks. The Fuel tanks have to be dropped to get to them.

So....... what is the cost to drop a GMC motorhome fuel tanks??? I don't know yet. I am still excited that we found the cause.

HOWEVER:

I drove over the the local GMC DEALER to see what they would do for me.
The first hint was his snicker when I told him I had a GMC Motorhome.
He sort of took a step back when I told him I needed the fuel tanks dropped and the fuel lines replaced.
When I pressed for an estimate, he said it would cost me $3000.00. Yes that was THREE THOUSAND DOLLARS.

I considered dropping the tanks myself but I don't have the racks nor the storage for the 3/4 full amount of gas that the motorhome is holding in the
fuel tanks.

I glanced around the shop and noticed that they do not have any racks to lift a vehicle like mine and they would have to raise it manually.
The obvious answer is they do not want to take on the job, and if they do, they plan to make me pay for it.

We've come so far and now I will be looking to see who can drop the tanks and change out the fuel lines. I will be more into it in the Spring but am
checking out possible places and pricing them out.

So if you listen to that dealer, that is what it costs to drop two GMC Motorhome fuel tanks... SHEEESH!

So I continue onward with this fiasco. Always open for any ideas.

Thanks to all............
--
GatsbysCruise. 74GMC Glacier Model.
 
Our GMC dealer says GMC never built a motorhome !!! No help there.

Sent from my iPhone

>
> First, I am most appreciative to all of you that have offered ideas to find this 10 year long search. I know how long it has been because that is
> when I bought the tires and aluminumum wheels and had the fuel lines replaced, which of course required dropping the fuel tanks.
>
> The power loss problem has persisted since, all this time as we searched, repaired, replaced and continued to test. I am thankful that I have at
> least been able to start the GMC so it isn't really a forgotten derelict. I always shutter when I hear stories about those GMC motorhomes. As my
> mechanic likes to repeat, vehicles do not get better sitting and rusting.
>
> So most of all of the accessories and some engine parts are new. Parts of the fuel line from the solenoid, to and including the Mechanical fuel pump
> are all new. Running the test connected to the normal fuel system, the power loss at 45mph is there.
>
> We finally made an effort to use the external gas can. This can be involved also now that the mechanical fuel pump has a return fuel line. unless
> that return line feeds to the external gas can, you won't have a very long run time.
>
> Testing with the external fuel can was SUCCESSFUL!! I took her down the highway on 3 different occasions doing 75mph and she still wanted to go
> faster. The problem has to be the lines to the tanks. The Fuel tanks have to be dropped to get to them.
>
> So....... what is the cost to drop a GMC motorhome fuel tanks??? I don't know yet. I am still excited that we found the cause.
>
> HOWEVER:
>
> I drove over the the local GMC DEALER to see what they would do for me.
> The first hint was his snicker when I told him I had a GMC Motorhome.
> He sort of took a step back when I told him I needed the fuel tanks dropped and the fuel lines replaced.
> When I pressed for an estimate, he said it would cost me $3000.00. Yes that was THREE THOUSAND DOLLARS.
>
> I considered dropping the tanks myself but I don't have the racks nor the storage for the 3/4 full amount of gas that the motorhome is holding in the
> fuel tanks.
>
> I glanced around the shop and noticed that they do not have any racks to lift a vehicle like mine and they would have to raise it manually.
> The obvious answer is they do not want to take on the job, and if they do, they plan to make me pay for it.
>
> We've come so far and now I will be looking to see who can drop the tanks and change out the fuel lines. I will be more into it in the Spring but am
> checking out possible places and pricing them out.
>
> So if you listen to that dealer, that is what it costs to drop two GMC Motorhome fuel tanks... SHEEESH!
>
> So I continue onward with this fiasco. Always open for any ideas.
>
> Thanks to all............
> --
> GatsbysCruise. 74GMC Glacier Model.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
> Our GMC dealer says GMC never built a motorhome !!! No help there.

> Sent from my iPhone

Well, that is kind of true. The GMC motorhome was designed as a sort of day cruiser for us. I think it had more commercial intentions but I never
saw a lot commercial types. Some show up now and then in the pics, but not in great numbers.
--
GatsbysCruise. 74GMC Glacier Model.
 
Read my write up on the tanks. I like doing things myself so I know what was done.

http://lqqkatjon.blogspot.com/2017/04/fuel-lines.html?m=1

There is an owner that just had there fuel tanks done in northwestern, illinios. I am not sure if they did them correctly, or at what price. Pm me
if you need me to find out.

You could also be dealing with a few other problems that maybe not related to a tank drop, such as defective selector valve or just plain stupid fuel
line routing or connections.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
There are ways to get to fuel pickups without dropping tanks l would try another selector valve or take the lines and use double barb fittings and
bypass it. There not much to the pickup but an elbow and filter sock but there could have been trash in the lines when they were replaced and got into
one of the turns in the selector valve
 
G'day,

Here's a link to the Fuel Tank section on Gene's website:

http://bdub.net/gmcmotorhome.info/Fuel.html

It goes without saying you need to be VERY careful when you cut the holes through the floor with the hole saw.

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

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Skip Hartline
Sent: Sunday, September 3, 2017 5:16 AM
To: gmclist
Subject: Re: [GMCnet] As my jouney continues.... That frikken power loss problem on Gatsbys' Cruiser

There are ways to get to fuel pickups without dropping tanks l would try another selector valve or take the lines and use double
barb fittings and bypass it. There not much to the pickup but an elbow and filter sock but there could have been trash in the lines
when they were replaced and got into one of the turns in the selector valve
 
Thanks everyone for being so helpful.

First, the fuel selection valves are brand new, part of the repair/upgrade as I searched for the power loss problem.

Just about everything is new, cept the hoses going to the top of the fuel tanks. I don't rule out the fuel pickups but I think since this all started
when the fuel lines were replaced, that the hoses might be pinched, so the tanks have to be dropped.

We added an electric fuel pump before the fuel valve solenoid and it didn't solve the problem which kind of tells me a supply problem.

Honestly, just about the only thing that has not been replaced are those fuel lines going to the fuel tanks. Strange that BOTH would be in trouble
but using either tank does not cure the power loss problem. Only the external fuel tank does. Kind of points to one critical area I think.

Thanks all

slc
--
GatsbysCruise.
74GMC260 Former Glacier Model style.
Located in Waukegan Keep those MiniDiscs Spinning
 
Stan,

I just hit send on the copy of how to get the tanks down and back up without killing yourself.
One thing I did not mention was that the last time I did this, I was already 65 and in only a little better shape than I am today (and that is bad).

Matt
--
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
 
The same restriction in both feed lines to the selector valve is suspicious. Has the (new) selector valve been checked for flow? Is there anything
else between where you connected the external tank and the selector valve?
I did renew both tanks and new lines with duel electric fuel pumps. Duct taping the fuel lines to the groove tn the top of the tank helps to prevent
pinching it.
You can use the electric fuel pump to empty the tanks, I empty my boat tank using it's electric fuel pump in the fall into 5 gal red plastic cans so I
can watch them fill, not overfill . I use it in other vehicles before it goes bad.
Raising the tanks with the GMC on jack stands using ratchet straps is not too bad. I'm only 63. :)
Duct taping the fuel and vent lines together to lay in the groove tn the top of the tank helps prevent pinching them.
--
Eric & Ree '74 ex-Sequoia (parts) '75 Eleganza (TB, exhaust x-over blocking plates, Manny reaction arms and discs, 3"exhaust rear muffler, aux vacuum,
fuel tank sealing, rebuilt senders and new rubber, propane hot water heater.) Alexandria, Ontario, Canada
 
> I just hit send on the copy of how to get the tanks down and back up without killing yourself. One thing I did not mention was that the last time I did this, I was already 65 and in only a little better shape than I am today (and that is bad).

Matt,

Best results are obtained when you take the tanks down, do the repairs with the vent and supply hoses reversed, put the tanks back up, realize the problem, drop the tanks again, correct the issue and then put them back up one last time. One feels far more satisfied with their achievement when the procedure is done this way. :)

Bob Burkitt and I did his tanks this afternoon on the drive-over pit; I think your name came up as we were putting it all back together. I’m pretty sure we double-checked our work about a dozen times before wrestling them back up into place; not to mention that Bob conked his head about a dozen times and one of those times may have left a dent in his sway bar - that may be a record for a GMC work party at the Miller Compound.

—Jim


Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH
 
My tanks have forehead-shaped dents all over them.

Rick "and not just the tanks" Denney

>
> > I just hit send on the copy of how to get the tanks down and back up
> without killing yourself. One thing I did not mention was that the last
> time I did this, I was already 65 and in only a little better shape than I
> am today (and that is bad).
>
> Matt,
>
> Best results are obtained when you take the tanks down, do the repairs
> with the vent and supply hoses reversed, put the tanks back up, realize the
> problem, drop the tanks again, correct the issue and then put them back up
> one last time. One feels far more satisfied with their achievement when the
> procedure is done this way. :)
>
> Bob Burkitt and I did his tanks this afternoon on the drive-over pit; I
> think your name came up as we were putting it all back together. I’m pretty
> sure we double-checked our work about a dozen times before wrestling them
> back up into place; not to mention that Bob conked his head about a dozen
> times and one of those times may have left a dent in his sway bar - that
> may be a record for a GMC work party at the Miller Compound.
>
> —Jim
>
>
> Jim Miller
> 1977 Eleganza
> 1977 Royale
> Hamilton, OH
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
 
Rick, "That's using the old noggin'." (Grin)
Jim Hupy
Got some of those myself, being 6' 2"+.

> My tanks have forehead-shaped dents all over them.
>
> Rick "and not just the tanks" Denney
>

>

> >
> > > I just hit send on the copy of how to get the tanks down and back up
> > without killing yourself. One thing I did not mention was that the last
> > time I did this, I was already 65 and in only a little better shape than
> I
> > am today (and that is bad).
> >
> > Matt,
> >
> > Best results are obtained when you take the tanks down, do the repairs
> > with the vent and supply hoses reversed, put the tanks back up, realize
> the
> > problem, drop the tanks again, correct the issue and then put them back
> up
> > one last time. One feels far more satisfied with their achievement when
> the
> > procedure is done this way. :)
> >
> > Bob Burkitt and I did his tanks this afternoon on the drive-over pit; I
> > think your name came up as we were putting it all back together. I’m
> pretty
> > sure we double-checked our work about a dozen times before wrestling them
> > back up into place; not to mention that Bob conked his head about a dozen
> > times and one of those times may have left a dent in his sway bar - that
> > may be a record for a GMC work party at the Miller Compound.
> >
> > —Jim
> >
> >
> > Jim Miller
> > 1977 Eleganza
> > 1977 Royale
> > Hamilton, OH
> >
> >
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
>
>
>
> --
> '73 X-Glacier 230 "Jaws"
> Northern Virginia
> Offlist email: rick at rickdenney dot com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
I helped a club member install the duel electric fuel pumps. When switching
to the aux tank no gas would pump. Blasted the fuel line with compressed
air and that cleared the fuel line.

> Rick, "That's using the old noggin'." (Grin)
> Jim Hupy
> Got some of those myself, being 6' 2"+.
>

>
> > My tanks have forehead-shaped dents all over them.
> >
> > Rick "and not just the tanks" Denney
> >

> >
> > > > On Sep 2, 2017, at 5:35 PM, Matt Colie

> > >
> > > > I just hit send on the copy of how to get the tanks down and back up
> > > without killing yourself. One thing I did not mention was that the
> last
> > > time I did this, I was already 65 and in only a little better shape
> than
> > I
> > > am today (and that is bad).
> > >
> > > Matt,
> > >
> > > Best results are obtained when you take the tanks down, do the repairs
> > > with the vent and supply hoses reversed, put the tanks back up, realize
> > the
> > > problem, drop the tanks again, correct the issue and then put them back
> > up
> > > one last time. One feels far more satisfied with their achievement when
> > the
> > > procedure is done this way. :)
> > >
> > > Bob Burkitt and I did his tanks this afternoon on the drive-over pit; I
> > > think your name came up as we were putting it all back together. I’m
> > pretty
> > > sure we double-checked our work about a dozen times before wrestling
> them
> > > back up into place; not to mention that Bob conked his head about a
> dozen
> > > times and one of those times may have left a dent in his sway bar -
> that
> > > may be a record for a GMC work party at the Miller Compound.
> > >
> > > —Jim
> > >
> > >
> > > Jim Miller
> > > 1977 Eleganza
> > > 1977 Royale
> > > Hamilton, OH
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > GMCnet mailing list
> > > Unsubscribe or Change List Options:
> > > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> > >
> >
> >
> >
> > --
> > '73 X-Glacier 230 "Jaws"
> > Northern Virginia
> > Offlist email: rick at rickdenney dot com
> > _______________________________________________
> > 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
>

--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
 
To get the gas out of the tanks:

1. Disconnect the fuel hose at the fuel selector from the tank that you want to empty.
2. Point the hose down and into a capture container.
3. Remove the gas cap.
4. Apply air pressure to the gill inlet with an air hose and a rag for 5 to 10 seconds.

The gasoline will siphon from there until that tank is empty.

Do the above for the second tank.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
If your rubber hoses were not replaced with barrier hose, they can fail in a few short years from ethanol, even if they were "new" then. They become a
bit like the garden weeper hose and can cause lots of issues with porosity including causing you to weep.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Having just done both tank I can say that it is a pain. But not a $3000 job. Before this you could consider the following;

Both lines having issues is suspicious, but possible.

Try running with the gas cap off, to see if there is a venting problem holding up flow.

Blow out the lines, less than 30 PSI at first. If you can put a guage on the air line to observe the drop it might be helpful. Take off the gas cap
first so you can hear what is going on. You might want to blow out the vent too.

Try tapping into the generator feed line on the rear tank instead of the normal feed and see what happens.

Worst case you could drop the front tank only, it is much easier. I used brake line from the tank to the edge so there was no issue pinching and
reducing flow. Thanks to others on the forum for this idea.
 
> Having just done both tank I can say that it is a pain. But not a $3000 job.

I suspect dropping the tanks would be difficult. I circumvented them because they had been checked when the fuel lines were replaced and I believed
that they HAD to be ok. All tests so far say this isn't so. Testing continues. As for a $3000 job, They just don't want to do it.



> Before this you could consider the following;
>
> Both lines having issues is suspicious, but possible.
>
> Try running with the gas cap off, to see if there is a venting problem holding up flow.
>
> Blow out the lines, less than 30 PSI at first. If you can put a guage on the air line to observe the drop it might be helpful. Take off the gas
> cap first so you can hear what is going on. You might want to blow out the vent too.
>
> Try tapping into the generator feed line on the rear tank instead of the normal feed and see what happens.

I FULLY AGREE. BOTH lines being pinched does not seem possible, but thats where all this has me looking now.
LOL, my fuel cap has no seal, some junk the prev PO bought. I've been looking to replace it but hasn't been found yet and other issues keep arising.
Was told to blow air in the lines to blow off the filter socks in the tanks, DONE.
I have been told of using metal lines on the tanks. How would you attach them to the tanks and seal them? Finding parts has always been my biggest
task.
I have already considered tapping the generator fuel line. But the line seems very small compared to the main lines. Been trying to figure how to
make the connection and that would be a great test.

> Worst case you could drop the front tank only, it is much easier. I used brake line from the tank to the edge so there was no issue pinching and
> reducing flow. Thanks to others on the forum for this idea.

--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Located in Waukegan \ Keep those MiniDiscs Spinning \ MY GREYOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-UBUNTU STUDIO
 
I saw pics of people putting a flare on the end of the pickup but that looked too hard. I just used a short section of rubber hose and hose clamps.
Your problem seems to be very challenging, all the usual trys have not improved things. Maybe a pressure gage right before the carb would help
quantify and maybe show some new info.
Good luck.
 
I like the pressure gauge but could also see a vacuum gauge just before the
fuel pump.
Instrumentation was my background. If you get an indication where the
problem is you have less of a system to troubleshoot.
Is there a safe way to have a permanent fuel pressure gauge at the
carburetor, preferably just before the float?

On Mon, Sep 4, 2017 at 7:47 AM, Randy Cohen/Catherine McGinley <

> I saw pics of people putting a flare on the end of the pickup but that
> looked too hard. I just used a short section of rubber hose and hose
> clamps.
> Your problem seems to be very challenging, all the usual trys have not
> improved things. Maybe a pressure gage right before the carb would help
> quantify and maybe show some new info.
> Good luck.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--

*John Phillips*
 
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