Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-03-2018, 08:03 PM   #1
New Member
 
Taylors , Arkansas
Join Date: Jul 2018
Posts: 2
1985-345 fuel pump problem

Hey guys, first time posting on here and hoping to get some insight on an issue Iím having with the fuel pump after the old went bad. I replaced the electric fuel pump at the tank with a holly Mfr. #: 12-801-1 because thatís what the Manuel stated as replacement for the P-30 Chasis but now when I crank it it only runs for about 15sec and then starves for fuel and cuts off. The new fuel pump is rated at 97gph and the old one was 110gph.
Could that be the issue ?

Thanks for any help!
Newty is offline   Reply With Quote
Old 07-03-2018, 08:23 PM   #2
Rivet Master
 
Waipio Rim's Avatar
 
1984 31' Airstream310
Honokaa , Hawaii
Join Date: Jun 2010
Posts: 942
If you still have the original carburetor setup there is also a mechanical fuel pump on the motor.
Waipio Rim is offline   Reply With Quote
Old 07-04-2018, 03:03 AM   #3
Rivet Master
 
WayneG's Avatar
 
1984 27' Airstream 270
Scotia , New York
Join Date: Oct 2012
Posts: 1,082
Hopefully your pickup tube screen in the tank is not full of "rust dust".
When I dropped the tank in my 84, I found about half a cup of loose rust particles in the tank.

When that stuff gets swirled up in the gas, it will get into your fuel pumps and clog filters (Hopefully you have one before the pump)
__________________
Do not take life too seriously.
You will never get out of it alive.
WayneG is offline   Reply With Quote
Old 07-04-2018, 04:56 AM   #4
Rivet Master
 
bobmiller1's Avatar

 
2005 34' Classic S/O
2006 39' Land Yacht 396 XL
north blenheim , New York
Join Date: Sep 2012
Posts: 2,539
I agree with Wayne, if it only runs for 15 seconds I would take the pressure side off the pump and run a long hose into a 5 gallon jug, turn the ignition switch on and check the flow, your problem is either the new pump or your suction side is blocked. For diagnostic Purposes if you find the suction side blocked, disconnect the suction side from the new pump and with a rubber tip blow gun, blow backwards into the fuel tank, if your problem is then solved I recommend dropping the tank, although that is a pain in the ass you may have got a bad tank of gas recently........Regards, Bob
bobmiller1 is offline   Reply With Quote
Old 07-04-2018, 07:16 AM   #5
Rivet Master
 
Boom Sounds's Avatar
 
1991 25' Airstream 250
Oxford , Oxfordshire
Join Date: Jun 2007
Posts: 1,133
Images: 5
May as well replace the filter on the frame rail which is a cheap and prudent fix and can rule that out
Boom Sounds is offline   Reply With Quote
Old 07-04-2018, 08:03 AM   #6
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 7,065
Images: 12
If the flow tests mentioned above check out OK I would check to see if the engine also has the standard mechanical pump mounted on the lower front of the engine block.


GM mounts that pump at the lowest point in the fuel system and water collects below the diaphragm. I had to remove one once for lack of flow at road speeds. I mud below the diaphragm and the edge of the diaphragm cracked and not making a complete seal.



I replaced the mechanical pump with a Carter electric and placed a mechanical pump cover plate on the engine block to cover the opening.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 07-04-2018, 09:26 AM   #7
3 Rivet Member
 
Currently Looking...
belen , New Mexico
Join Date: Jan 2012
Posts: 191
Fuel pump

I agree that thereís one at the engine. The elec one is just there to get the fuel to the engine pump due to a long trip from the tank.
alantbird is offline   Reply With Quote
Old 07-04-2018, 02:30 PM   #8
Rivet Master
 
Waipio Rim's Avatar
 
1984 31' Airstream310
Honokaa , Hawaii
Join Date: Jun 2010
Posts: 942
there is also a screen in the carburetor where the fuel line connects that can get fouled.
Waipio Rim is offline   Reply With Quote
Old 07-04-2018, 06:27 PM   #9
3 Rivet Member
 
Grosspoluter's Avatar
 
1984 34.5' Airstream 345
Franklin Park , Illinois
Join Date: Jan 2015
Posts: 181
I had a similar problem But I had NO electric pump at the tank, just the mechanical pump on the engine, that set up only gave me only 2-3 psi at the carb.
After i installed the electric pump at the tank the psi at the carb. went up to 5-8 and drivability went way up
I still run with both pumps
Grosspoluter is offline   Reply With Quote
Old 07-05-2018, 12:04 AM   #10
3 Rivet Member
 
1987 34.5' Airstream 345
Auckland , New Zealand
Join Date: Feb 2014
Posts: 133
Hi Newty,
Fuel supply in these long vehicles can cause issues, some sensible tricks once your'v cleared your current pos blockage, as has been stated befor, that the steel gas tank can start to lose its electro plating on its interior, as condensation inside will ocure, so will rust! To leason this get hold off a large Base Speaker, donut shaped magnet and attatchet beneath the pickup position on the tanks bottom. This will collect all the metal rust n stuff. Untill someone wonders what i'st doing there an removes it.
You want both an electrical pickup pump so fuel is forced under preasure to the engines mechanical pump so in the event off electrical failure your not left sitting in the middle lane.
Also these benifit from a fuel regulator to maintain a 5 psi at carburettor, otherwise thoes two pumps at times will pump up to unhealthy presures thus flooding fuel into the engine, cost plus rough running particularly at idlle.
All the above after filter changes are done, should be good to go...
Rus
Voltair is offline   Reply With Quote
Old 07-06-2018, 07:07 AM   #11
New Member
 
Taylors , Arkansas
Join Date: Jul 2018
Posts: 2
Quote:
Originally Posted by Waipio Rim View Post
there is also a screen in the carburetor where the fuel line connects that can get fouled.
I'm going to check this....
Newty is offline   Reply With Quote
Old 07-06-2018, 08:11 AM   #12
Rivet Master
 
bkahler's Avatar

 
1974 20' Argosy 20
Richmond , Kentucky
Join Date: Jan 2003
Posts: 8,553
Quote:
Originally Posted by Newty View Post
I'm going to check this....
Actually it's a small filter that is fitted inside the carburetor right where the gas line connects.
__________________
Air forums # 1674
1974 20' Argosy Motor Home
1974 31' Excella trailer (parting out, as of 4/1/2015 I have wheels, brake drums, windows & holding tanks left to sell)
bkahler is offline   Reply With Quote
Old 08-26-2020, 03:27 PM   #13
2 Rivet Member
 
1996 34' Excella
1996 36' Classic 36
Thousand Oaks , California
Join Date: Sep 2006
Posts: 20
My 1985 airstream 3450 motor home sat for few years in the hot Needles California sun. I drained the old gas and started and it ran fine. After few days, when I tried starting it, it won't stop flooding the carburetor. I replaced with the brand new Quad Edelbrock carb and this problems still persist. I am told that there's a pressure cutout relay for fuel pressure issue. I looked and looked I can't find such a relay. What could be the issue with this really bad situation? Thanks
edmelik is offline   Reply With Quote
Old 08-27-2020, 08:19 PM   #14
4 Rivet Member
 
1987 34.5' Airstream 345
Menomonee Falls , Wisconsin
Join Date: Jul 2010
Posts: 418
Hey
If you have an electric fuel pump back by the tank. Make sure its not a high pressure pump. They look very similar. When I put my fuel injection on I had to buy a new pump. They are identical. One has a black ring around it the other is a red ring. The low pressure pump puts out 13 pounds the high pressure pump puts out 65 pounds. If you got the high pressure pump on a stock carb with no regulator it will overpower the needle valve in the carb. Thus flooding. If you got dirt in the line it can flood. When you put the new carb on did you put a new filter on too. Close to the carb.
Stalling in 15 seconds sounds like the bowl is emptying but not filling back up. I'd be looking at the block fuel pump. It will pump fuel up. But not enough to keep it running. Gas today is really hRd on the diaphragms in the old fuel pump. That would be my guess on the starvation problem . Could also be a coil problem. But thats pretty obscure. When it starts to die. Crack the throttle a little. A little you should see a squirt of fuel . Don't trounce on the throttle. Back fires are hard on the eyebrows when your looking down into the carb. If you don't see fuel she's starving out. If you see fuel its either flooding or something else is causing it to die. Maybe coil related. To my knowledge there is no relay for fuel . Unless you got a computer controlled fuel system. If its a quadrajet carb with a block mounted fuel pump. Then you got a stock set up. Fuel filter fuel pump or blockage in fuel line. Dl
davejay is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need help finding the air compressor pump location on my 1985 A/345 tlholley General Motorhome Topics 21 02-21-2015 09:39 AM
belts, hoses and rear fuel pump for 1986 345 MH? Jenniflow Classic Motorhomes 12 05-26-2012 12:42 PM
Fuel tank leak 1985 345 classic st.stephan Classic Motorhomes 3 04-03-2011 10:08 PM
Fuel pump question 1988 345 moeriv Classic Motorhomes 11 10-02-2010 11:29 AM
Electric fuel pump and fuel line routing cooperhawk Mechanics Corner - Engines, Transmission & More... 7 02-06-2003 10:16 AM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 05:54 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.