Fuel delivery problem?

[michael1]

So as I mentioned in a previous thread the coach stumbled and died going up hill. While waiting for replacements for the fuel filter line I decided to
try turning it over on flat ground to see if fuel would come out of the line. Nothing. Where is the fuel pump? Is it mechanical? Does the line need to
be connected to draw fuel?

I had it towed to a spot behind my job but now parking enforcement is telling me to move it so I am in a time crunch!

(Again thank you to all who have contributed with your vast knowledge!)
--
1977 Palm beach
Bham AL

 

[wayne rogewski]

Assuming everything is stock and not messed with. The fuel pump is mechanical. Carter 6108 is the model/part number 25 bucks ish at most part
stores that may have it in stock. 6108 is the one you want with no 3rd line for a return.

The fuel pump is connected directly to the other end of the fuel line that was stripped going to the carb. Two bolts hold it to the block in the
front passenger side of the engine.

The pump is connected to the tanks in the back and unless you are darn near empty on both tanks is should be pulling fuel as you crank the engine.
Trace the metal line from the fuel pump (not hooked to the carb) back and see if you have any other inline filters anywhere that can be plugged.

Depending on how old the fuel hoses are, they may be cracked, collapsed, or sucking air causing a problem, but again it was running and an incline
appeared to have caused the issue.

I suspect you may not have enough gas in the tanks. Since is was running fine and the incline caused the issue. While your waiting for the fuel
line, dump another 10-15 gallons in. that way either tank that is selected should have enough to pull from.

Do yourself a favor and pull the oil dipstick and smell it. If it smells like raw fuel, STOP, do not pass go. The pump let go and dumped fuel into
oil pan.

If the dip stick is at a normal level and doesnt stink like gas you should be fine.
--
77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
Mid Michigan

 

[michael1]

Shouldn't it be pumping now that it's on level ground? Does the carb need to be primed or will simply turning it over be enough?
--
1977 Palm beach
Bham AL

 

[sgltrac]

If you still have the stock mechanical pump and you have enough fuel in the
tanks and you do not have some other restriction and your fuel pump is
working then yes fuel should squirt out the open line you removed from the
carburetor.

Sully
Bellevue wa

> Shouldn't it be pumping now that it's on level ground? Does the carb need
> to be primed or will simply turning it over be enough?
> --
> 1977 Palm beach
> Bham AL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[sgltrac]

While cranking the motor.

> If you still have the stock mechanical pump and you have enough fuel in
> the tanks and you do not have some other restriction and your fuel pump is
> working then yes fuel should squirt out the open line you removed from the
> carburetor.
>
> Sully
> Bellevue wa
>

>
>> Shouldn't it be pumping now that it's on level ground? Does the carb need
>> to be primed or will simply turning it over be enough?
>> --
>> 1977 Palm beach
>> Bham AL
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>

 

[john phillips]

These units are notorious for running out of gas going uphill. The gas runs
away from the fuel pickup. The line is then full of air. The fuel pump does
not pump air well. It takes quite a bit of cranking to pump all the air out
of the line after there is plenty of gas at the fuel pickup site.

It may have been better to have the pickup set up so you run out of gas
going downhill.

> Shouldn't it be pumping now that it's on level ground? Does the carb need
> to be primed or will simply turning it over be enough?
> --
> 1977 Palm beach
> Bham AL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--

*John Phillips*

 

[wayne rogewski]

The engine turning over is what drives the mechanical pump. Provided you have enough fuel in the selected tank while cranking the fuel should be
coming out of the currently stripped line you have going to the carb body. It may take 10-15 seconds of cranking or more if the line pulled a bunch
of air up when the coach was on the incline.

If that line is still stripped be very very very careful about spilling raw fuel all over the top of the engine.

what do the fuel gauges say on the dash when you are on level ground and you flip the tank selector? If they are both reading at a 1/4 you should
have plenty in the tanks to draw from.
--
77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
Mid Michigan

 

[Jim Hupy]

Modern alcohol blended gasoline will make short work of the stock selector
valve. It will appear o.k. on the outside, but the internals will
deteriorate and block the flow of fuel, particularly when there is not much
fuel in the tanks. If you are low on fuel and climb a steep incline with
the selector switch on "Aux", it will quit running.
Just a couple things to check.
Jim Hupy
Salem, Or

> The engine turning over is what drives the mechanical pump. Provided you
> have enough fuel in the selected tank while cranking the fuel should be
> coming out of the currently stripped line you have going to the carb
> body. It may take 10-15 seconds of cranking or more if the line pulled a
> bunch
> of air up when the coach was on the incline.
>
> If that line is still stripped be very very very careful about spilling
> raw fuel all over the top of the engine.
>
> what do the fuel gauges say on the dash when you are on level ground and
> you flip the tank selector? If they are both reading at a 1/4 you should
> have plenty in the tanks to draw from.
> --
> 77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson
> carb and dizzy.
> Mid Michigan
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Matt Colie]

> So as I mentioned in a previous thread the coach stumbled and died going up hill. While waiting for replacements for the fuel filter line I
> decided to try turning it over on flat ground to see if fuel would come out of the line. Nothing. Where is the fuel pump? Is it mechanical? Does the
> line need to be connected to draw fuel?
>
> I had it towed to a spot behind my job but now parking enforcement is telling me to move it so I am in a time crunch!
>
> (Again thank you to all who have contributed with your vast knowledge!)

Bronevaya,

As Warren wrote, the fuel pump is mechanical. It is on the right front of the engine (both 455 and 403), but many of us have found damage due to both
age and alcohol. If it is not pumping when you crank the engine, that is your problem.

There are a huge number of possibilities here.
How much of the fuel system has been replaced with new materials?
If you don't know, it probably hasn't been done and cracks (very common) in the old rubber fuel lines can cause this any time.

My current suggestion would be to arrange an alternate fuel supply to move the coach to a better location.

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

 

[terry1]

Gotta go with Matt on the primary solution to your problem, which is the parking enforcement authority. Get the coach outta there before they "adopt"
it and charge you for any number of expenses. Definitely check the dipstick as mentioned earlier by 77 Royale because you don't want to fill the
crankcase with fuel and blow the engine apart on the first crank. Strap a 5 gallon gas can on the front bumper and run a hose from it to the fuel
pump. Prime the carb with a tablespoon of fuel and crank to see if it runs. Might take 2 or 3 tries to get the pump, line, and carb filled. If the
pump won't pump then you'll have to go the dangerous way and put the gas can on the floor inside and hook it up to the carb, bypassing the pump. This
is very dangerous for some people as it will require a siphon to be set up so the fuel will flow to the carb. A portable marine gas tank for outboard
motors is the safest way to do this, most of them having a primer bulb in the line. The needle and seat in the carb will hold the fuel back from
siphoning too much, but do not leave the setup intact after moving the coach to your better spot because bad things happen with unattended siphon
setups in any type of liquid.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[Ken B]

Depending on how far you are going, a smaller tank on the bumper might be fine. On the coach I am working on, the main tanks have 19 year old gas in
them and they are 1/2 full. I haven't tackled that problem yet so I use a 2.5 gallon tank strapped behind the bumper to to supply clean fuel to move
the coach, and to drive it less than 20 miles. I have moved coaches hundreds of miles using a 5 gallon can on the bumper and stopping every 40 miles
to fill it up. That means carrying several extra 5 gallon cans inside in case there is not a station every 40 miles.

I tried the marine tank in the cockpit but the gravity feed never did work very well. Also I had to make a new adapter to attach it to the carb.

On this coach I simply disconnected the hose on the input side of the fuel pump and ran it to a filter. Then on the other side of the filter I ran a
long 3/8" hose up to the bumper mounted tank.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[kosier]

Ken,

A bunch of years ago, I decided to build an auxiliary fuel tank. Called a
friend who runs a Marina. He said he had some boat tanks that
had been replaced under warranty. Neither he nor the owners could find
anything wrong with them. FREE if I came for it. So I did.
I also got into his junk box and found a quick disconnect to go on the
outlet. Three inches of hose, a pre-filter and a low pressure
electric fuel pump and a long piece of gas hose let's me put the tank
anywhere the hose can reach. Actually, I put a valve in the middle
of the hose that's never been used, but it let's me disconnect it at that
point and just use the shorter hose. have a short piece of
3/8" steel fuel line with an elbow in that let's me go right in the carb.
I've used it a bunch of times for different things.
I forgot to mention that I took a long piece of lamp cord, put a couple of
alligator clips on one end and plugged it on to the pump.

Gary Kosier
77PB w/500Cad
Newark, Ohio

-----------------------.---------------------------
From: "Ken Burton"
Sent: Wednesday, August 08, 2018 11:31 AM
To:
Subject: Re: [GMCnet] Fuel delivery problem?

> Depending on how far you are going, a smaller tank on the bumper might be
> fine. On the coach I am working on, the main tanks have 19 year old gas
> in
> them and they are 1/2 full. I haven't tackled that problem yet so I use a
> 2.5 gallon tank strapped behind the bumper to to supply clean fuel to move
> the coach, and to drive it less than 20 miles. I have moved coaches
> hundreds of miles using a 5 gallon can on the bumper and stopping every 40
> miles
> to fill it up. That means carrying several extra 5 gallon cans inside in
> case there is not a station every 40 miles.
>
> I tried the marine tank in the cockpit but the gravity feed never did work
> very well. Also I had to make a new adapter to attach it to the carb.
>
> On this coach I simply disconnected the hose on the input side of the fuel
> pump and ran it to a filter. Then on the other side of the filter I ran a
> long 3/8" hose up to the bumper mounted tank.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org