GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Re: [GMCnet] EFI vs Carb
Re: [GMCnet] EFI vs Carb [message #326459 is a reply to message #326445] Tue, 28 November 2017 22:24 Go to previous messageGo to next message
Richard Denney is currently offline  Richard Denney   United States
Messages: 920
Registered: April 2010
Karma: 9
Senior Member
I had to replace the in-tank pump in an Audi--a very good Bosch pump. Any
pump can fail.

Rick "since you asked :) " Denney

On Tue, Nov 28, 2017 at 3:54 PM Emery Stora wrote:

> True, but how often are you planning to replace them?
>
> Mine have been in for 8 years now and are still working fine.
>
> If one were to fail then I still have the other — or if I didn’t have the
> time to replace an in-tank one I could always hook up an outside the tank
> one temporarily. The in-tank pumps do allow fuel to be pulled through it
> by an external pump.
>
> The in-tank pump in my 1973 Jeep Grand Cherokee still worked after 42
> years when I traded it in. How many of you have ever had to replace an
> electric in-tank pump in their automobile?
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Re: [GMCnet] EFI vs Carb [message #326461 is a reply to message #326445] Wed, 29 November 2017 07:26 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
i agree in-tank pumps are both harder to install, and harder to change. But when you talk to those that went that route it seems vapor lock is gone.

There are trade off's to all systems. A person has to make up there own mind and live with it.


Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: [GMCnet] EFI vs Carb [message #326462 is a reply to message #326459] Wed, 29 November 2017 07:34 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
I have dealt with numerous electric fuel pump failures.

Funny about chevy astro's. We changed quite a few. I remember getting one replaced under warantee only to have our mechanic break the replacement trying to install the lock ring. That was a $400 whoops.

Once on a Chevy suburban.

Couple ford e-250's.

My 93 cherokee never had an issue. I did rip the wires off that once in the woods, then punched a hole in the gas tank a year later in that same woods. So had the fuel pump out twice on that. But my 98 jeep wrangler lost a pump as did a friend's 94 wrangler.


3-4 fuel pumps on my vw sand rail. Those I should not count, but I can think of a few after market fuel pumps that were installed in a gmc motorhome that went bad.

I also live where it is -30 some weeks in winter and 100 in summer. Winters are hard on fuel pumps.


Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/

[Updated on: Wed, 29 November 2017 07:36]

Report message to a moderator

Re: [GMCnet] EFI vs Carb [message #326464 is a reply to message #326461] Wed, 29 November 2017 08:18 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

I intend to install low pressure in-tank pumps (7 psi) to feed a surge tank up front which can feed the mechanical fuel pump or a
high pressure FI pump. The surge tank will have a return plumbed into the 1/2 inch vent tube for the fuel filler.

1) cut off the tubes off a defective tank sender
2) drill a hole in the center of the tank sender
3) put a screw with a sharpened end through the hole and install in the tank(s)
4) raise the tank(s) into position
5) the screw will put a mark on the aluminum sheet that covers the Styrofoam insulation
6) drill a 1/8 inch hole up through the aluminum sheet, Styrofoam, and plywood floor
7) using the 1/8 inch hole as a guide cut a 6 inch hole using a fly cutter
8) using a router along the edge of the 6 inch hole create a step for a 1 inch thick plug with a stepped edge
9) cover the floor with high grade vinyl
10) carefully cut out the 6 inch hole in the vinyl and glue it to the plug
10) make a custom fit carpet to cover the area and bind the edges

This will provide access to the pumps should they require replacement.

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@list.gmcnet.org] On Behalf Of Jon Roche
Sent: Wednesday, November 29, 2017 7:26 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb

i agree in-tank pumps are both harder to install, and harder to change. But when you talk to those that went that route it seems
vapor lock is gone.

There are trade off's to all systems. A person has to make up there own mind and live with it.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] EFI vs Carb [message #326465 is a reply to message #326033] Wed, 29 November 2017 08:53 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
My personal experiences with Mopar in tank pump assemblies in Jeeps is they are very long lived compared to most other high pressure in tank pumps in the industry, which are short lived. Back to the GMC carb vs EFI debate-- if the reason for doing it is vapor lock, that can be corrected by installing an external feed through low pressure pump near the Aux tank and opperated via the existing Aux seitch via a relay with total parts costs well under $100. I have found all the wrapping and insulating a futile exercise. VL occurs before the mech pump in my opinion. Flip the switch and it's fixed every time. Also a well set up Qjet will start smoothly, transition cold to warm seamlessly and be very dependable. The only reason I would go to EFI is if I lived or drove a lot at altitude. It can't add air density but can pull fuel automatically at altitude keeping the engine more in the correct range to make the most of the thin air

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] EFI vs Carb [message #326474 is a reply to message #326033] Wed, 29 November 2017 12:15 Go to previous messageGo to next message
GMC Jimmy is currently offline  GMC Jimmy   Canada
Messages: 199
Registered: September 2016
Location: Niagara, Ontario
Karma: 2
Senior Member
Thanks again everyone for your input.

John, Vapor Lock is one reason for considering EFI, the main reason is peace of mind for all-around driving. I live in Ontario, Canada, not much in the way of altitude in my area although I plan to drive to California in the spring.

I would like reliability, I realize there are challenges with both systems and that a properly tuned carb and distributor can address my concerns. I wasn't looking for a reason to spend two thousand dollars for an EFI set-up, I simply understood that an EFI system could be a more efficient and a potentially less troublesome route... everyone has their own opinion and experience with each.

My initial post asked for real world experiences rather than anecdotal opinions so I could base my choice on practical over theory. I
was directed to FaceBook as there is a group that discusses the Fitech set-up in the GMC motorhome, unfortunately I'm not a FB guy.

The quest continues,
Thanks,
Mike


Re: [GMCnet] EFI vs Carb [message #326480 is a reply to message #326464] Wed, 29 November 2017 14:49 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
Rob-

2 quick things.
Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need a really big hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper. Not saying it cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to service?

2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out the foam, and drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.

If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.


Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: [GMCnet] EFI vs Carb [message #326481 is a reply to message #326480] Wed, 29 November 2017 15:23 Go to previous messageGo to next message
bdub is currently offline  bdub   United States
Messages: 1578
Registered: February 2004
Location: Central Texas
Karma: 5
Senior Member

I have 6" holes in the floor rabbited out to 7" on top 1/2" so the cover
won't fall out. I had to put on a new 2" piece of fuel resistant hose to
couple the fuel pump to the output tube. My first one disintegrated after
a couple of months and left me dead on the side of the road. Yes, I
switched pumps to pull from but that pressure went straight into the rear
tank because the pump connection wasn't there to stop it! Anyhow, I was
able to easily pull out the pump and sender assembly, repair, and
re-assemble without any trouble. Even with the o-ring seal.

bdub

On Wed, Nov 29, 2017 at 2:49 PM, Jon Roche wrote:

> Rob-
>
> 2 quick things.
> Do you know anybody who has cut the holes in the floor and what diameter
> and have r+r there fuel pumps through that hole??
> I see that option talked about, and good in theory, I never heard how well
> it worked out in real life. I keep thinking you need a really big hole
> to manouver the fuel pump in and out of the tank, as well as getting the
> lock rings twisted and in place square and proper. Not saying it cant be
> done, but when I have looked at accessing the fuel senders 2-3 " below the
> floor, i wonder how big of a hole is needed to service?
>
> 2nd item is when I have had fuel tanks down it is more then obvious where
> to drill up. The last coach I did, i hole sawed out the foam, and drilled
> up into carpet with a 1/4" bit. You wont need to lift the tank to mark
> anything from bottom.
>
> If you look at my photos you will see the factory already has a hole for
> senders. At least on my 75 and the 77 i did tanks on.
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.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



bdub
'76 Palm Beach/Central Texas
www.bdub.net
www.gmcmhphotos.com
www.gmcmotorhomemarketplace.com
www.gmcmhregistry.com
www.facebook.com/groups/classicgmcmotorhomes
www.facebook.com/groups/gmcmm
Re: [GMCnet] EFI vs Carb [message #326482 is a reply to message #326480] Wed, 29 November 2017 15:30 Go to previous messageGo to next message
bdub is currently offline  bdub   United States
Messages: 1578
Registered: February 2004
Location: Central Texas
Karma: 5
Senior Member

Oh and don't bet the farm on those existing cutouts in the insulation being
perfect fit for the tanks. Both mine were off about a half inch.

bdub

-----Original Message-----
From: Gmclist On Behalf Of Jon Roche
Sent: Wednesday, November 29, 2017 2:50 PM

2 quick things.
Do you know anybody who has cut the holes in the floor and what diameter and
have r+r there fuel pumps through that hole??
I see that option talked about, and good in theory, I never heard how well
it worked out in real life. I keep thinking you need a really big hole
to manouver the fuel pump in and out of the tank, as well as getting the
lock rings twisted and in place square and proper. Not saying it cant be
done, but when I have looked at accessing the fuel senders 2-3 " below the
floor, i wonder how big of a hole is needed to service?

2nd item is when I have had fuel tanks down it is more then obvious where to
drill up. The last coach I did, i hole sawed out the foam, and drilled
up into carpet with a 1/4" bit. You wont need to lift the tank to mark
anything from bottom.

If you look at my photos you will see the factory already has a hole for
senders. At least on my 75 and the 77 i did tanks on.


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



bdub
'76 Palm Beach/Central Texas
www.bdub.net
www.gmcmhphotos.com
www.gmcmotorhomemarketplace.com
www.gmcmhregistry.com
www.facebook.com/groups/classicgmcmotorhomes
www.facebook.com/groups/gmcmm
Re: [GMCnet] EFI vs Carb [message #326492 is a reply to message #326033] Wed, 29 November 2017 17:51 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
Mike, if you want piece of mind--you can't beat a Qjet. As far as efficiency, I have never seen a post here about how they get better MPG with EFI. Have seen several posts about dead in water with EFI or orphaned systems with no parts and support.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] EFI vs Carb [message #326493 is a reply to message #326480] Wed, 29 November 2017 17:52 Go to previous messageGo to next message
wally is currently offline  wally   United States
Messages: 643
Registered: August 2004
Location: Omaha Nebraska
Karma: 5
Senior Member
lqqkatjon wrote on Wed, 29 November 2017 14:49
Rob-

2 quick things.
Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need a really big hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper. Not saying it cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to service?

2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out the foam, and drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.

If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.

We made floor access for in tank pumps. 1/8 aluminium plates recessed to floor level over a 6 inch hole. Self adhesive floor tile over it. Marked hole location while the tanks were out and I could see where the senders actually were by rub marks.
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
HTH


Wally Anderson
Omaha NE
75 Glenbrook
Re: [GMCnet] EFI vs Carb [message #326498 is a reply to message #326493] Wed, 29 November 2017 19:46 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Wally,

Thanks for responding to this thread, I didn't realize that the tanks were as far forward as they are. I really like the self
adhesive floor tile idea.

I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.

How did you connect the lines that go across the top of the tank to the lines that go up the side of the coach in the frame rails? I
plan on having some braided stainless steel flex hoses made up for that purpose.

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@list.gmcnet.org] On Behalf Of Wally Anderson
Sent: Wednesday, November 29, 2017 5:53 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb

lqqkatjon wrote on Wed, 29 November 2017 14:49
> Rob-
>
> 2 quick things.
> Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
> I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need
a really big
> hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper.
Not saying it
> cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to
service?
>
> 2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out
the foam, and
> drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.
>
> If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.

We made floor access for in tank pumps. 1/8 aluminium plates recessed to floor level over a 6 inch hole. Self adhesive floor tile
over it. Marked hole
location while the tanks were out and I could see where the senders actually were by rub marks.
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
HTH
--
Wally Anderson
Omaha NE
75 Glenbrook
Megasquirt III injection
Bob Stone hydroBOOOOST
Manny reaction arm system
Branscombe Kelsey Hayes park brake
http://wallyandsue.blogspot.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



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] EFI vs Carb [message #326508 is a reply to message #326498] Wed, 29 November 2017 21:08 Go to previous messageGo to next message
wally is currently offline  wally   United States
Messages: 643
Registered: August 2004
Location: Omaha Nebraska
Karma: 5
Senior Member
Rob, I used Dorman nylon fuel tube like newer cars and trucks use OEM. Those Dorman fittings are made to go from steel tube to their nylon tube. Same scheme to connect the forward end.
I did put external check valves in both pump lines as I had read of others who had issues if a pump check sticks open or a line comes off in the tank leading to an instant stop.
So far so good.

USAussie wrote on Wed, 29 November 2017 19:46
Wally,

Thanks for responding to this thread, I didn't realize that the tanks were as far forward as they are. I really like the self
adhesive floor tile idea.

I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.

How did you connect the lines that go across the top of the tank to the lines that go up the side of the coach in the frame rails? I
plan on having some braided stainless steel flex hoses made up for that purpose.

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@list.gmcnet.org] On Behalf Of Wally Anderson
Sent: Wednesday, November 29, 2017 5:53 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb

lqqkatjon wrote on Wed, 29 November 2017 14:49
> Rob-
>
> 2 quick things.
> Do you know anybody who has cut the holes in the floor and what diameter and have r+r there fuel pumps through that hole??
> I see that option talked about, and good in theory, I never heard how well it worked out in real life. I keep thinking you need
a really big
> hole to manouver the fuel pump in and out of the tank, as well as getting the lock rings twisted and in place square and proper.
Not saying it
> cant be done, but when I have looked at accessing the fuel senders 2-3 " below the floor, i wonder how big of a hole is needed to
service?
>
> 2nd item is when I have had fuel tanks down it is more then obvious where to drill up. The last coach I did, i hole sawed out
the foam, and
> drilled up into carpet with a 1/4" bit. You wont need to lift the tank to mark anything from bottom.
>
> If you look at my photos you will see the factory already has a hole for senders. At least on my 75 and the 77 i did tanks on.

We made floor access for in tank pumps. 1/8 aluminium plates recessed to floor level over a 6 inch hole. Self adhesive floor tile
over it. Marked hole
location while the tanks were out and I could see where the senders actually were by rub marks.
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
http://wallyandsue.blogspot.com/2014/07/floor-plates-for-access-to-fuel-senders.html
HTH
--
Wally Anderson
Omaha NE
75 Glenbrook
Megasquirt III injection
Bob Stone hydroBOOOOST
Manny reaction arm system
Branscombe Kelsey Hayes park brake
http://wallyandsue.blogspot.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




Wally Anderson
Omaha NE
75 Glenbrook
Re: [GMCnet] EFI vs Carb [message #326510 is a reply to message #326508] Wed, 29 November 2017 21:30 Go to previous messageGo to next message
Billy Massey is currently offline  Billy Massey   United States
Messages: 916
Registered: January 2004
Location: Central Texas
Karma: 1
Senior Member

Wish I'd a used those check valves.

bdub

On Nov 29, 2017 9:14 PM, "Wally Anderson" wrote:

Rob, I used Dorman nylon fuel tube like newer cars and trucks use OEM.
Those Dorman fittings are made to go from steel tube to their nylon tube.
Same scheme to connect the forward end.
I did put external check valves in both pump lines as I had read of others
who had issues if a pump check sticks open or a line comes off in the tank
leading to an instant stop.
So far so good.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



bdub
bdub.net
Re: [GMCnet] EFI vs Carb [message #326514 is a reply to message #326508] Wed, 29 November 2017 22:29 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Wally,

I want to use Poly Armour and put it on the outside of the frame because I'm hoping to plumb the water that condenses on the A/C
evaporator to the fuel line and the latent heat of vaporization will cool the fuel.

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@list.gmcnet.org] On Behalf Of Wally Anderson
Sent: Wednesday, November 29, 2017 9:08 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] EFI vs Carb

Rob, I used Dorman nylon fuel tube like newer cars and trucks use OEM. Those Dorman fittings are made to go from steel tube to their
nylon tube. Same scheme to connect the forward end.
I did put external check valves in both pump lines as I had read of others who had issues if a pump check sticks open or a line
comes off in the tank leading to an instant stop.
So far so good.



_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] EFI vs Carb [message #326607 is a reply to message #326514] Fri, 01 December 2017 17:22 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
USAussie wrote on Wed, 29 November 2017 23:29
Wally,

I want to use Poly Armour and put it on the outside of the frame because I'm hoping to plumb the water that condenses on the A/C
evaporator to the fuel line and the latent heat of vaporization will cool the fuel.

Regards,
Rob M.

Rob,

In April of 2012, I replaced just about all the rubber fuel line with Ployarmor. I used a jewelers saw (very fine hacksaw) to cut the bubble off the fittings on the tank access and then used brass compression fittings to make the connection. That makes 5 years and about 40K miles that they have been good. I cheated, I copied what Emery did.

Matt



Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] EFI vs Carb [message #368535 is a reply to message #326498] Sun, 23 January 2022 11:16 Go to previous messageGo to next message
Ken M is currently offline  Ken M   United States
Messages: 32
Registered: December 2019
Location: Redding, CA
Karma: 0
Member
USAussie wrote on Wed, 29 November 2017 17:46
Wally,

I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.

Regards,
Rob M.
Hi Rob,
I’m resurrecting an old thread here… I am working on adding hard lines to the top of my tanks. I have purchased some of the swagelok that you have often recommended in various postings. I also have the polyarmor line… my question is - what kind of fitting should be used to connect the two, in order to facilitate separating the two if needed. I am adding in tank pumps, and will be cutting an access hatch in the floor. So I’m needing a good way to separate the swagelok to hardline in the event that I have to work on the fuel pump. Do I just use some sort of 3/8” union or??? Do you have a link to a particular Union that you’d recommend?


1975 - 26’ Eleganza II Unsure of what upgrades may have been done. I'm working on sorting that out in the coming months. Ken Morefield - Redding, CA
Re: [GMCnet] EFI vs Carb [message #368536 is a reply to message #326498] Sun, 23 January 2022 11:49 Go to previous messageGo to next message
Ken M is currently offline  Ken M   United States
Messages: 32
Registered: December 2019
Location: Redding, CA
Karma: 0
Member
USAussie wrote on Wed, 29 November 2017 17:46
Wally,

I note you've used what appears to be 3/8' flareless fittings to connect the senders to what appears to be Poly Armour tubing, I
have Swagelok 3/8" flareless to 38 degree male stainless steel fittings. The flareless connection would connect to the sender
fittings and the flared connection to the Poly Armour tubing.

Regards,
Rob M.
Hi Rob,
I’m resurrecting an old thread here… I am working on adding hard lines to the top of my tanks. I have purchased some of the swagelok that you have often recommended in various postings. I also have the polyarmor line… my question is - what kind of fitting should be used to connect the two, in order to facilitate separating the two if needed. I am adding in tank pumps, and will be cutting an access hatch in the floor. So I’m needing a good way to separate the swagelok to hardline in the event that I have to work on the fuel pump. Do I just use some sort of 3/8” union or??? Do you have a link to a particular Union that you’d recommend? http://www.gmcmhphotos.com/photos/member-galleries/p68417-swagelok2polyarmor.html


1975 - 26’ Eleganza II Unsure of what upgrades may have been done. I'm working on sorting that out in the coming months. Ken Morefield - Redding, CA

[Updated on: Sun, 23 January 2022 11:58]

Report message to a moderator

[GMCnet] Re: EFI vs Carb [message #368537 is a reply to message #368535] Sun, 23 January 2022 11:43 Go to previous messageGo to next message
Billy Massey is currently offline  Billy Massey   United States
Messages: 916
Registered: January 2004
Location: Central Texas
Karma: 1
Senior Member

Remove the bulb off the end of the suction line on the sender and connect
it with a compression union.

https://www.amazon.com/Legines-Brass-Compression-Fitting-Union/dp/B075L5PVRP/ref=sr_1_4?keywords=3%2F8+compression+union&qid=1642959685&sr=8-4

https://www.gmcmi.com/wp-content/uploads/2013/02/In_tank_Fuel_Pump_Presentation.pdf
bdub



> Hi Rob,
> I’m resurrecting an old thread here… I am working on adding hard lines to
> the top of my tanks. I have purchased some of the swagelok that you
> have often recommended in various postings. I also have the polyarmor
> line… my question is - what kind of fitting should be used to connect the
> two, in order to facilitate separating the two if needed. I am adding in
> tank pumps, and will be cutting an access hatch in the floor. So I’m
> needing a good way to separate the swagelok to hardline in the event that
> I have to work on the fuel pump. Do I just use some sort of 3/8” union
> or??? Do you have a link to a particular Union that you’d recommend?
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:


bdub
bdub.net
Re: [GMCnet] EFI vs Carb [message #368543 is a reply to message #326033] Sun, 23 January 2022 18:12 Go to previous messageGo to previous message
Bullitthead is currently offline  Bullitthead   United States
Messages: 1411
Registered: November 2013
Karma: 5
Senior Member
GMC came with Weber Edelbrock carb when I got it...noticed the hatch was crushing the air cleaner but still made it home from Danville OK. Drove it around town twice before swapping out the 600CFM Weber for the Quadrajet I had on my Bronco II V6. Runs nice, smooth, and have to be slow taking off in the rain going right. Even with the 3.07 F.D. And doesn't crush the air cleaner (which also came from the Bronco II).
Anyway, I went and bought a '69 Firebird and drove it up from Florida back in 2019. Came with a Holley 750 and corresponding Edelbrock intake. Terrible gas mileage, terrible fumes, reasonable power, didn't start right up when cold, and didn't run worth a fart until it was warm. Hood also trying to crush air cleaner. I knew I was going to change that carb before I bought that car but it ran good the day I got it.
After it's introduction to cold, damp Virginia, driveability became worse every ride and finally decided to put the Quad on there, like from the factory, but this meant changing the manifold since I could not use an adapter, just like on the GMC (because of extra height).
Gotta bench full of Quads, so bought and swapped manifold using crossover block plates (have not done this on GMC yet)and proceeded to play musical carbs using stock on hand and had one that really agreed with the engine. It came off my boat, and had no PCV or power brake vacuum ports. Started right up, ran like crazed cocroach in full escape mode. Decided to get a rebuilt Quad from EBAY, bad move, assembled from mismatched parts (airhorn not right for main body)and no returns. Found correct parts in collection and assembled working carb. Put on car and would not run right, figured I didn't get the rebuild right, but couldn't see what was wrong. Got another rebuilt quad, this time from JEGS. Really pretty, matched parts, replated butterflys, polished exterior, same $300. as the one from EBAY.Started right up, ran 8 seconds and quit. then repeat, holding/pumping throttle until it was warm but still would not run right. CLUE: only pulling 7 inches of vacuum at idle, NO vacuum leaks, smoked it to be sure. Finally took a functioning carb off other Firebird and tried that, could not adjust it to run even though smooth as glass on other engine (these are both 350s).
Well, rowing across the fuel induction river I was now halfway to the price of fuel injection, so do I keep plugging/sinking with these carbs or row back and get a different kind of boat? I chose the new boat and ordered the F.A.S.T. system since it was advertised as fitting the Quad manifold I had installed. I have decided that the P.O. put too big of a cam in there and the injection removes the variable fuel delivery at low RPM due to the low vacuum.
It's wonderful, starts right up, lopes a little until I load it going up the hill, and then I have to be careful to not tear up the gravel driveway. System comes with its own external H.P. pump that I am feeding off the stock mechanical pump. They want the pump lower than the tank and that isn't happening until the front of the car. Might be a little power drop-off at full throttle right now, but it's still real quick the 100mph, good enough to get me arrested so I'm just liking it right now. It was expensive, but at least I can now drive my antique car without a half-hour prep. And hardly any fumes from unburned fuel, actually cleaner than the GMC.
Now I see the price has gone up $400. !!! I just got it back in December for $1467...ridiculous,price gouging, but here is a link:

https://smile.amazon.com/gp/product/B016V2BB3U/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1


Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.

[Updated on: Sun, 23 January 2022 18:15]

Report message to a moderator

Previous Topic: Happy Birthday -Matt Colie
Next Topic: Daytona International Speedway
Goto Forum:
  


Current Time: Thu Mar 28 07:49:44 CDT 2024

Total time taken to generate the page: 0.02578 seconds