Jurjen, can you explain a little about the check valve? I thought the reason for having a return line was to let excess fuel return to the fuel tank rather than flooding the carb. I can see that a check valve would prevent the carb from draining dry, but will the check valve not prevent the return line doing its job? What becomes of the excess fuel?
Could you give us a picture of where and how you installed the valve?
Hi, Jim.
I did not want to "release" this feature yet, because I have not had it in there for more than a week.
I already made the pictures.
You are right, the free flow should go from filter return to tank.
I try to make use from another physical quality of the check valve, the so called "cracking pressure" that is the pressure that holds the ball in the seat. My hope is that it will prevent the fuel filter from draining to the tank.
The cracking pressure is normally very low, something like 1 to 3 psi.
I have tried a two-way filter (so w/o a fuel return line) before, but had so much fuel pressure (I guess the "full" 7psi) that the carb would flood after switching the engine off. I tried a new float needle but that didn't help either.
I hope the pictures are clear enough, I bought a metal 1/4" check valve ($5) and put it in the rubber hose that runs from the filter return to the metal tube that runs back to the tank.
(http://i197.photobucket.com/albums/aa237/jurjen_eagle/IMG_0496.jpg)
No, it is not the yellow thing in the vacuum line....
(http://i197.photobucket.com/albums/aa237/jurjen_eagle/IMG_0494.jpg)
The old man in his YBR (yellow brick road) workshop (found that on the camera, picture secretly taken by my wife)
(http://i197.photobucket.com/albums/aa237/jurjen_eagle/IMG_0459.jpg)
So has it been working so far? I was wondering, do you think it would work if you put the check valve on the line after the fuel filter before the carb? That way when the engine is turned off, the carb doesn't drain back to the tank through either the supply or return hose.
That is a very good idea, but has the same problem as the two-way filter: it keeps the high pressure on the carb, so it floods.
I don't know if it works like it is now, it takes about three days to drain back and I do sometimes use the car within that period (and then it starts-up right away).
But as said before, I will keep you posted.
Quote from: Jurjen on August 10, 2011, 04:42:34 PM
That is a very good idea, but has the same problem as the two-way filter: it keeps the high pressure on the carb, so it floods.
If it was between the carb and filter (still using the filter w/return line), wouldn't it keep the fuel from draining out of the carb, yet still allow excess pressure to go through the return line. The check valve would only function when the engine is off.
Quote from: ammachine390 on August 10, 2011, 07:25:24 PM
Quote from: Jurjen on August 10, 2011, 04:42:34 PM
That is a very good idea, but has the same problem as the two-way filter: it keeps the high pressure on the carb, so it floods.
If it was between the carb and filter (still using the filter w/return line), wouldn't it keep the fuel from draining out of the carb, yet still allow excess pressure to go through the return line. The check valve would only function when the engine is off.
seems like that would work correctly.
Jurjen keep us posted on any advances on this.
From looking at your pictures I would recommend changing all your rubber hoses, they are dry roted, and I can see some of them are the factory originals.
Thanks Gil, I saw that some of them were cracked, so I did change a bunch of them.
I last used the Eagle on Tuesday, today (Friday) it fired right-up. It looks like it is not draining back in three days any more.
The Pierburg company gives only two reasons for putting a non return valve in the return fuel line:
• NRV in the return line
- Used as a safety valve near the tank
in order to prevent it from draining if
a line ruptures.
- Used near the carburetor or before
the fuel vapor separator, to avoid
flooding the float chamber from the
return line if the vehicle tilts sharply.
Here is the link:
http://download.fwheel.com/KATALOG/PIERBURG/CD/catalog/BROSCHUEREN/PG/PG_Kraftstoffanlagen_en_WEB.pdf
When you study the schematics, you will find that some have a pressure regulator in the return line, or a non return valve and a flow restrictor with a 1 or 2 mm hole.
Hope this is helpful, I found this in the 1981 TSM, Page 1J-6:
"All AMC automobiles with six-cylinder engines have a fuel return system to reduce the possibility of high temperature fuel vapor problems. The system consists of a line connecting from a nipple on the fuel filter to a nipple located on the fuel tank sending unit assembly. The fuel filter is installed with the return nipple positioned at the top of the filter. During normal operation, a small amount of fuel returns to the tank. During periods of high underhood termperature, vaporized fuel is returned to the tank rather than entering the carburetor (fig. 1J-9). Also a check valve in the fuel return system at the fuel filter hose eliminates any possibility of fuel feeding back to the carburetor through the fuel return line.
The in-line check valve has a stainless steel, spring-assisted, check ball to close the orifice (fig 1J-10). Pressures of 0.1 to 0.6 psi (0.69 to 4.14 kPa) from the fuel filter side opens the check valve and permits normal operation of the fuel return system.
The check valve is bullet-shaped and located in the forward end of the hose/filter-to-tank tube. If it is reversed, the fuel return system will not operate.
AMC automobiles with four-cylinder engines do not have a fuel return system (fig. 1J-11)."
Quote from: vangremlin on August 12, 2011, 10:01:07 PM
The fuel filter is installed with the return nipple positioned at the top of the filter.
I wonder if the filter is positioned any other way, it would not work properly? This could be what is giving jim's car the problem of not starting when hot.
After reading (and contributing) to this thread, I will now be recovering any check valves I come across in Eagles I find in the junkyards. There is one that just arrived this week in Denver that I am going to check out tomorrow, plus another one that has been there for a couple months that I will see if it still has a check valve.
QuoteThe in-line check valve has a stainless steel, spring-assisted, check ball to close the orifice (fig 1J-10). Pressures of 0.1 to 0.6 psi (0.69 to 4.14 kPa) from the fuel filter side opens the check valve and permits normal operation of the fuel return system.
The check valve is bullet-shaped and located in the forward end of the hose/filter-to-tank tube. If it is reversed, the fuel return system will not operate.
So I put in what already should have been there.
Someone must have installed a new rubber hose at one point, and must have overlooked the check valve.
the only valves I have found in parts cars still have the original factory clamp on the return line on the fender. If a person is unaware that it is there, it will get thrown out with the old hose.
Rita
Here is the picture of the check valve from the TSM:
(http://i197.photobucket.com/albums/aa237/jurjen_eagle/check_valve.jpg)
Seeing the picture, I just checked my hose.
It has a hard part towards the fender INSIDE the hose.
So this valve is pushed INSIDE the hose about 1" from the end near the fender.
I understand now why they become thrown away.
Mine must be leaky, because of the drain back I had before.
I will pry it out and make a picture.
I visited a junk yard this morning - 2 Eagles, no check valves. The first car is an SX-4 that just arrived this week but I think they stripped a lot out of it before it got there. I was looking and looking for the return line and could not find it. I finally looked at the emissions sticker and I got my answer. This car originally had a 4 cyl engine, therefore no return line and no check valve. It was interesting though because there seemed to be a lot more room between the engine and the firewall than in my car that originally came with the 6 cyl.
Second car is a 1980 wagon that has been there for a couple months. The fuel return line must have been replaced at sometime during the car's life, as there was no check valve. I'll keep hunting!
Both my Eagles have had the fuel hose replaced. I may have thrown away check valves without realizing it. I often keep old hoses in case of emergency. I'll look through my junk.
Is this a common item that can be found easily?
My fuel filters are oriented properly.
Quote from: Jurjen on August 13, 2011, 02:27:52 PM
Seeing the picture, I just checked my hose.
It has a hard part towards the fender INSIDE the hose.
Yes, that is where I found the one on my car, inside the hose.
they have a very fine/weak spring inside that can be spiraled out with needle nose pliers, the steel ball can be cleaned and all put back in. One that I found had part of the spring coming out keeping the ball from closing back. I did take it apart and cleaned it up. Hopefully it works, I put it in Reitan's Eagle.
Rita
QuoteIs this a common item that can be found easily?
The AMC check valve is not a common part.
But the 1/4" check valve I put in, can be found in every car part store (or on the auction site).
It works the same way.
And here are the pictures we have all been waiting for:
(http://i197.photobucket.com/albums/aa237/jurjen_eagle/IMG_0498.jpg)
Cut the old hose open and what did I find?
(http://i197.photobucket.com/albums/aa237/jurjen_eagle/IMG_0500.jpg)
A very small check valve.
So I checked it's function (blowing through it) and it was still working fine.
Put a little dish washing detergent on it and pushed it in a new 1/4" hose and installed it again.
Jurjen so would this be a factory set up?
Yes, back to 100% factory set up (for the time being).
Has anyone tried to find out if the original type valve is available anywhere?
The part number is in the Eaglepedia, section 13:
"J3232 144 Valve"
But I cannot find it anywhere on the www.
Maybe at your local Chrysler/Jeep dealer?
I tried to go to chryslerdirect to look for it but it now requires a login using a dealer name. I have bought parts there in the past.
I have tried chryslerpartsdirect, kennedyamerican, amcramblerparts and americanpartsdepot.
No luck.
You can put in a general 1/4" fuel check valve: it has the same function.
Quote from: Jurjen on August 13, 2011, 02:27:52 PM
Seeing the picture, I just checked my hose.
It has a hard part towards the fender INSIDE the hose.
So this valve is pushed INSIDE the hose about 1" from the end near the fender.
I understand now why they become thrown away.
Mine must be leaky, because of the drain back I had before.
I will pry it out and make a picture.
Hallo Jurjen,
Een paar weken geleden heb ik een aantal verouderde vacuum en bezineslangetjes laten vervangen.
Wat kunnen de problemen zijn/worden als de check valve niet meer in het benzineslagetje zit?
Heb je enig idee waar ik een nieuwe check valve kan kopen? Mijn donoreagle staat in de stalling, mogelijk vind ik daar de reserve valve.
Mvgr Willem van Twist
For those who want to know, just try Google translate....
Today I went to 4 parts stores and a large hardware store. Most were of no help at all. One ordered the valve but it had female ends. I didn't want to deal with trying to find nipples. There isn't much room anyway; valve and nipples would take up a lot of the hose.
QuoteHallo Jurjen,
Een paar weken geleden heb ik een aantal verouderde vacuum en bezineslangetjes laten vervangen.
Wat kunnen de problemen zijn/worden als de check valve niet meer in het benzineslagetje zit?
Heb je enig idee waar ik een nieuwe check valve kan kopen? Mijn donoreagle staat in de stalling, mogelijk vind ik daar de reserve valve.
Mvgr Willem van Twist
Translation
Hi Jurjen,
A few weeks ago, I have some old vacuum tubes and gasoline replaced.
What problems can / will be the check valve is no longer in benzineslagetje?
Have you any idea where I can buy a new check valve? My donor eagle is in storage, may I find the reserve valve.
Mvgr William Twist
I found the valve on ebay. I'm waiting for an answer to my question about shipping, but I plan to buy 2 of them regardless.
QuoteTranslation
That is a pretty good translation! Benzineslangetje = fuel hose.
Have the original set-up again, but it is draining back to tank again. So will will put my new check valve back in.
The spring inside has weakened over time, try to take it out and pull it "a bit" to strengthen it slightly and / or the ball and / or seat has corroded, take apart and clean seat / replace ball.
Jurgen I keep seeing that in-line check valve That you found in the factory fuel hose and just can't figure out what where they thinking when that set it up hidden like that.
Any chance the original check valve is design to slow down the fuel return insted of completely stopping it?
I think that it works like a cheap and dirty pressure regulator like used in EFI systems.
After switching off the hot engine it will also allow the vapours to escape to tank.
Adjustable pressure regulators are available in the 1-7 psi range, but expensive.
It will behard to get theold check valve out now, so I will leave it in and add my new valve.
You can also find these check valves in 81-83 Concord/Spirit. Also note that the TSM for 81 states that 81 is the first year for these.
I bought a check valve on ebay Sunday, received it Wednesday, installed it in the 88 Thursday night. Cranked it and let it run a few minutes. I'l wait a couple of days before I start it again.
I don't know what to think. The first 2 times it started so quickly it startled me. I let it sit a day and it was hard to start, back to its old ways. The next time it started immediately. I'll try it again tomorrow after letting it sit overnight.
I'm running the Motorcraft carb and an Aeromotive adjustable fuel pressure regulator. I no longer have the check valve and use a standard fuel filter. My car can sit a week and I'll give the accelerator pedal two pushes and it cranks up immediately. However, when warm, if I let it sit for more than a couple minutes, I have to crank it for a while before it starts. If it sits for more than a half hour it will start up like normal.
Quote from: eaglefreek on September 01, 2011, 10:30:41 PM
I'm running the Motorcraft carb and an Aeromotive adjustable fuel pressure regulator. I no longer have the check valve and use a standard fuel filter. My car can sit a week and I'll give the accelerator pedal two pushes and it cranks up immediately. However, when warm, if I let it sit for more than a couple minutes, I have to crank it for a while before it starts. If it sits for more than a half hour it will start up like normal.
This may be due to the intake being directly above the exhaust manifold.
Quote from: maximus7001 on September 02, 2011, 04:27:50 PM
Quote from: eaglefreek on September 01, 2011, 10:30:41 PM
I'm running the Motorcraft carb and an Aeromotive adjustable fuel pressure regulator. I no longer have the check valve and use a standard fuel filter. My car can sit a week and I'll give the accelerator pedal two pushes and it cranks up immediately. However, when warm, if I let it sit for more than a couple minutes, I have to crank it for a while before it starts. If it sits for more than a half hour it will start up like normal.
This may be due to the intake being directly above the exhaust manifold.
I have often wondered that. However it doesen't happen to the other 2 DD's. Just my stroker with msd fired ignition. 21?? Somthing carb. So that to me rules it out. Also I had an 80 kee that never ever started hard.
The 88 sat for 6 days and started immediately, and again after sitting all day while I was at work, and even better this morning after sitting over night. I have to believe the check valve made the difference. That's the only change that has been made.