Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-20-2017, 08:17 PM   #1
3 Rivet Member
 
Vintage Kin Owner
1987 32.5' Airstream 325
Windsor , Ontario
Join Date: Dec 2006
Posts: 119
No fuel to my carburator? can't start

Help, cannot start my 87' MH (325) after it being parked since May!!!

No troubles starting and running on my last trip in May. Recently recharged the battery (after running down with radio play) and it started right up. Now a week away from my Labour Day trip, I went to start to do my pre-trip checks and nothing....there is no fuel going to the carb.

I have checked the tank and there is fuel in there, all lines seem good with no leaks, did not pull off the filter but it is under two years old. I pulled off the line to the carb and tried to suck some fuel up but nothing came through. Fuel pump is less than two years old as well.

The only thing I can think of is replacing the fuel pump but would like to hear if there is anything else I can troubleshoot? Is there a thread on fuel pump replacement.

thanks in advance for any replies,
Chris
__________________

realpank is offline   Reply With Quote
Old 08-20-2017, 09:59 PM   #2
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,729
Replace the fuel filter, not the fuel pump. Replace the fuel, too.

My dad used to own a lawn mower and small engine repair shop, and every spring, there would be a rash of customers who had stored their mowers, blowers, chainsaws, etc. with fuel in them, and the gasoline had gone bad. Ethanol gasoline is only good for about 90 days from the date the ethanol was added to the gasoline. Ethanol is hygroscopic, meaning that it readily absorbs water. But the petroleum in the fuel doesn't absorb much water, only the ethanol does. The fuel then experiences something called "phase separation," meaning that it separates into two layers, a layer of gasoline on top of a layer of watered-down ethanol.

Petroleum distillates like gasoline can chemically absorb about 150ppm of water, but ethanol can absorb up to 7000ppm of water, or nearly 50 times as much water as the gasoline does.

So my guess as to what has happened is that your fuel filter is full of watered-down ethanol due to the fuel being too old, so the filter is clogged even though it's only full of liquid. And that's why you're not getting fuel to the engine.

By the way, don't buy any additives to prevent water absorption by ethanol. There is no such thing, even though there are products marketed that claim to do so. Your best bet for storage in the future is to store the motorhome with as little fuel in it as possible (1 gallon of E10 will absorb a lot less water than will 20 gallons of E10), and add fresh fuel to top off the tank before trying to start it again when you take the motorhome out of storage.

On edit— In my opinion, this is one reason why most newer vehicles have un-vented fuel tanks with an air gap at the top for expansion (and why un-vented gas cans are available as well), because if there's no vent, the only time moisture-laden air gets in is when you fill the tank. No humid air, no water in the gas, no phase separation. So this is a phenomenon that's much more prevalent with older vehicles with vented tanks where air and moisture can enter through the vent.
__________________

__________________
Cats and ultraleather Airstream upholstery don't mix!
Protagonist is offline   Reply With Quote
Old 08-20-2017, 10:21 PM   #3
Rivet Master
 
TG Twinkie's Avatar
 
1974 Argosy 26
Morrill , Nebraska
Join Date: Nov 2009
Posts: 5,821
Images: 2
Blog Entries: 5
Disconnect the fuel line at the carb. Connect a piece of hose to the line. Place the hose in to a collection container. Crank the engine to see if you get fuel.
You could have a stuck needle and seat in the carb. Not uncommon with E10 fuel.
__________________
Knowledge: "A gift to be shared. A treasure to receive."
TG Twinkie is online now   Reply With Quote
Old 08-22-2017, 06:30 AM   #4
3 Rivet Member
 
Vintage Kin Owner
1987 32.5' Airstream 325
Windsor , Ontario
Join Date: Dec 2006
Posts: 119
No fuel to carburetor, can't start

Thanks for the replies.

Got it started, whew.

Forced the issue by putting a little raw gas in the carb, that kick started it and runs fine now. All the heat I recon was vapour lock
realpank is offline   Reply With Quote
Old 08-22-2017, 06:35 AM   #5
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,729
Quote:
Originally Posted by realpank View Post
Forced the issue by putting a little raw gas in the carb, that kick started it and runs fine now. All the heat I recon was vapour lock
Been so long since I've had to deal with vapor lock that I completely forgot about that possibility. Reducing vapor lock is one reason they started putting the fuel pump back at the tank so it pushes the fuel rather than being on the engine so it sucks the fuel.

Suggestion for reducing vapor lock in the future, get some foam pipe insulation and wrap the fuel line with it, all the way from the tank to the engine compartment.
__________________
Cats and ultraleather Airstream upholstery don't mix!
Protagonist is offline   Reply With Quote
Old 08-22-2017, 08:38 AM   #6
4 Rivet Member
 
Byron Center , Michigan
Join Date: Aug 2017
Posts: 275
Quote:
Originally Posted by Protagonist View Post
Suggestion for reducing vapor lock in the future, get some foam pipe insulation and wrap the fuel line with it, all the way from the tank to the engine compartment.


Keep that flammable foam a long way from exhaust manifolds and pipes! Car-b-cues are no bueño.
YippieKiYa is offline   Reply With Quote
Old 08-22-2017, 11:12 AM   #7
Rivet Master
 
Waipio Rim's Avatar

 
1984 31' Airstream310
Honokaa , Hawaii
Join Date: Jun 2010
Posts: 855
I used header wrap on my fuel lines, starting where they run close to the header pipes on the right side of the engine. Got a noticeable improvement by wrapping the hard line that comes up the front of the engine from the fuel pump to the carburetor.
Waipio Rim is offline   Reply With Quote
Old 08-22-2017, 12:46 PM   #8
3 Rivet Member
 
Grosspoluter's Avatar
 
1984 34.5' Airstream 345
Franklin Park , Illinois
Join Date: Jan 2015
Posts: 172
All good information here
I think I might try wrapping the fuel line on my 345
I also might add my 345 did NOT have a electric fuel pump at the fuel tank, and I beleieve when under acceleration it was fuel starved, I have since added a electric fuel pump just outside the tank that pumps fuel to the mechanical fuel pump on the engine then the mechanical pump pumps fuel to the carburetor
Grosspoluter is offline   Reply With Quote
Old 08-22-2017, 02:16 PM   #9
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,729
Quote:
Originally Posted by YippieKiYa View Post
Keep that flammable foam a long way from exhaust manifolds and pipes! Car-b-cues are no bueño.
Good point! Maybe I was just naïve to think that the motorhome builders would have better sense than to run a fuel line right next to an exhaust pipe.
__________________
Cats and ultraleather Airstream upholstery don't mix!
Protagonist is offline   Reply With Quote
Old 03-02-2018, 05:09 AM   #10
3 Rivet Member
 
OttawaValleyGuy's Avatar
 
1991 35' Airstream 350
Barry's Bay , Ontario
Join Date: Aug 2008
Posts: 152
I have a problem with my 1991 fuel injected 454
There is only 3 pounds pressure at the carburetor
I have replaced the filter
Any suggestions
__________________
Howard and Ann Schutt
OttawaValleyGuy is offline   Reply With Quote
Old 03-02-2018, 05:43 AM   #11
4 Rivet Member
 
Byron Center , Michigan
Join Date: Aug 2017
Posts: 275
Fuel pump?

I’m also a little confused- is it fuel injected, or carbureted? 3# is light for a carb’d engine (but it should be ok to start/idle), and just plain low for a FI engine (not enough to start).
YippieKiYa is offline   Reply With Quote
Old 03-04-2018, 05:44 AM   #12
3 Rivet Member
 
OttawaValleyGuy's Avatar
 
1991 35' Airstream 350
Barry's Bay , Ontario
Join Date: Aug 2008
Posts: 152
I will try to explain my problem more clearly
My 1991 350LE is stock
I drove over a hundred miles without a sputter or hiccup
I parked it, an hour later tried to start it
Starts but will not run or idle
I replaced the only filter I could find which was near the frame just to the rear of the entrance door
No luck
I took the line off what I call the carburetor
Put a pressure gauge on the line, cranked the engine, showed 3 pounds
Is there another filter?
Could the pickup tube be blocked
Defective pump?
If so does the tank need to be dropped?
It is throttle body injected

Thanks for any assistance
__________________
Howard and Ann Schutt
OttawaValleyGuy is offline   Reply With Quote
Old 03-04-2018, 10:12 AM   #13
Rivet Master
 
Waipio Rim's Avatar

 
1984 31' Airstream310
Honokaa , Hawaii
Join Date: Jun 2010
Posts: 855
Post #129 in this thread:

http://www.airforums.com/forums/f311...-95034-10.html

Has a link to the 1990 Service Manual. That was apparently the bridge year between carburetors and TBI systems, as the manual has information on both in chapter 7. My 1990 has a carburetor, with two fuel pumps external to the fuel tank. If your TBI unit is built as the manual describes (never a certainty), you will have one electric pump inside the tank. If I were faced with your problem, before either dropping the tank or cutting a hole in the floor to access it from above I would disconnect the line feeding the TBI unit as close to the tank as possible, hook your gauge up, turn the key on, and see what pressure you get. The manual says that you need pressure in the teens to make the TBI unit work.
Waipio Rim is offline   Reply With Quote
Old 03-05-2018, 04:20 PM   #14
Rivet Master
 
Boom Sounds's Avatar
 
1991 25' Airstream 250
Oxford , Oxfordshire
Join Date: Jun 2007
Posts: 958
Images: 5
Spot on. One pump at fuel tank and one main filter on frame rail roughly half way along. There is (I believe) another filter with the pump at the fuel tank. Defo worth looking at access options from above which might avoid dropping the tank. Also worth looking at the air lock issue in the 1990/91 chassis manual. I think it was a service bulletin. If you are getting that reading it sounds like fuel supply. I would check carefully before you attempt the fuel pump though. If you find pressure is OK, check your TBI unit for injector issues or blown gaskets.
__________________

Boom Sounds 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
Soft Start - Easy Start - Smart Start..? JConsroe Generators & Solar Power 13 06-16-2017 07:36 AM
Carburator for my 1985 345 Lido&Linda Mechanics Corner - Engines, Transmission & More... 10 01-20-2017 03:33 AM
My RV will start using the Aux Start but not with the chassis battery mcm9970 Land Yacht/Legacy Motorhomes 7 05-19-2013 07:47 PM
Fuel Line & Fuel Tank crazeevw Mechanics Corner - Engines, Transmission & More... 4 12-02-2011 07:38 PM
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.




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:06 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.