Hi Busnuts!
My generator which cuts out when the fuel sloshes in the tank is now about 90% fixed - now it only stops when the fuel is down about 50-60% AND I have a strong brake application. If that happens then I need to re-prime.
So, following busnut suggestions, I now have my check valve to install - purchased from grainger. BUT no flow arrows on the check valve for us non-engineer trained.
The recommended checkvalve is model 1A859.
http://www.grainger.com/Grainger/wwg/productIndex.shtml?from=Search&newSrch=yes&operator=keywordSearch&search_type=keyword&action=Go!&QueryString=1a859&submit.x=29&submit.y=12 (http://www.grainger.com/Grainger/wwg/productIndex.shtml?from=Search&newSrch=yes&operator=keywordSearch&search_type=keyword&action=Go!&QueryString=1a859&submit.x=29&submit.y=12)
There is a diagram on the side - could someone please help me understand which way to mount the valve? All I have is attached below - and I'm sure that hieroglyphics mean SOMETHING!! ;D :D ;D
The valve has female 3/8 outlets on both sides.
Thank you!
Phil
Phil; I believe the valve is showing flow from left to right. The symbol shows the ball closing flow from right to left. Test it with air first
in case I'm wrong. I've done that before. Good luck.... Cable
Thanks Cable !! And I will run the air test. Great idea. ;D
Best Regards, Phil
Just blow through it.
Hmmm. I apparently don't have enough "wind" to blow through it - wonder if the GPM is too high for this application? Listed as 8 GPM on the check valve. I know the generator draws about 1 gal p/hr.
Thanks - Phil
Got a compressor? I think pressure is your problem. You must open the valve before you get any flow. I expell lots of balloon juice with very little pressure...Cable
Thank you - will use the compressor. So, does it look like I am using the correct check valve? I'm double checking as I need to seat-fit on the 3/8" fitting, and also, I think that if I get the valve covered w/ fuel, I may have a problem returning it if it is the wrong (expensive) model.
Thanks!
Phil
I don't think that check valve is going to work for you. Looks like a hydraulic valve rated at 2000 psi. I think the check is going to be way too strong for your fuel pump.
You need a fuel check valve, one that you could blow through with negligible resistance.
Maybe this one http://www.garageautotools.com/S-U-R-R-SRRCKV7-p/srrckv7.htm
Len
Thanks Len - that is very logical, and I appreciate the alternative solution. That saves me some headaches - and I got enough headaches aready!! Wrico made a recommendation, and Grainger translated - but I think something was lost in the translation. :D
Kind Regards, Phil
The same check as used on your engine will work great, and provide you with a working spare on the road.
Under specs cracking pressure is 5psi..............I do think your air compressor can handle that :)
Brass are for air and hyd. per spec :) :)
Skip
Phil, are you pushing fuel through the check valve or pulling it,pushing it use a .4 crack pressure pulling it use a .1 cracking pressure valve.
The valve Len recommends is a good valve but the cost from DD is outrageous 80 bucks and remember some are 45 ,90 degree and vertical installed valves all check valves are not created equal good luck
Actually, I'm having a hard time understanding why you need a check valve. If you are having problems starting the generator after it sits a while, then it makes sense that it is loosing prime and a check valve will help.
If the generator if failing going down the road, then you have another problem. I would suspect a leak in your pick up tube which is allowing air in when the fuel sloshes away from it. Don't most electric fuel pumps have a check built in?
Len
The check valve has nothing to do with the fuel needed to run the generator.
The need for the check valve has to do with the coach engine pulling the fuel away from the genny and starving it for fuel
Oh and the standard aluminum check valve available at your local truck parts house will do just fine
and I believe the opposite is also possible
hope this helps
Chris
Phil,
Are you using the same pickup for both the engine and generator? Generally not a good practice, should be separate pickup tubes and the gen tube should not extend as far into the tank as the engine tube so that the genny cannot run you out of fuel.
Quote from: Len Silva on June 28, 2009, 07:18:39 PM
Phil,
Are you using the same pickup for both the engine and generator? Generally not a good practice, should be separate pickup tubes and the gen tube should not extend as far into the tank as the engine tube so that the genny cannot run you out of fuel.
Len just curious as to why this is not a good idea?
with the proper check valve it works fine and you have one less hose and potential leak to worry about
just my view
Thanks
chris
Hi Len,
No. They are completely separate assemblies, feeds, etc..
I'm still not sure why prime is being broken - I had a very large previous thread on this - but I do know it made a big difference to move the pump much closer to the tank. I now only have about 6 inches between the fuel pump and the fuel tank. 1 flare fitting, and I don't know what the other fitting is. My flare fitting wasn't extremely tight. but it wasn't flopping around either. :D Copper tube (3/8 " ) goes into the fuel tank about 24 inches. Looks to be about 4-5 inches off the bottom of the tank.
I'll try to post more pictures of the assembly when I can get back home near the bus. We'll be travellling again in a couple of days, so hopefully more photo opps.
Thank you!
Phil
Phil....your problem is that you have too large pick-up tube. Why...the bigger tube inside dimension the more liquid/weight to lift and once the air entered while fuel's level is below pick-point during braking with the flow is too slow to fill up the inter displacement of extra large pick-up tube. You posted ½" in the earlier post.
Remedy to fix this problem is to install 5 or less psi (or whatever is less than generator's pumping) relief valve after the first electric pump. The relief pressure goes to fuel tank to dump air and/or fuel. This way you will always have fuel only going to the generator's pump.
If you can find a relief valve...you can use a small needle valve instead. Adjust the relief flow so that it can maintain at least above .5 (point-5) psi to generator's pump
I suggest replacing pick-up for smaller one that the generator spec calls for....that alone will reduce most of your problem.
Sojourn for Christ, Gerald
Phil,
I had a similar problem on a 102A3 that I installed a Powertech generator in. It would run fine and after a while it would die. I determined it was definately a fuel issue. What I finally found was a cracked brass fitting on the suction side of the pump. It would work OK until the fuel warmed up the fitting causing it to expand slightly and allow the crack to open. Jack
PS: I have used 3/8" tubing for tank pick-up tube in several tanks with no problems yet.
Phil,
I feel pretty positive that your problem is a leak in the suction line somewhere between the pump and the fuel. At this point I would just replace the whole thing, suction leaks can be very hard to find. Something is happening in the tank when you hit the brakes. A tiny split in the pickup tube is being uncovered, or the tube itself is shifting in a fitting.
Chris,
Most every generator or fuel heater installation manual I have read calls for a separate pickup, primarily because the larger user can starve the other for fuel. Even if that doesn't happen, the most practical reason is so that the generator pickup can be installed a few inches above the main engine pickup so that the generator cannot run you out of fuel and leave you stranded in the desert to die a miserable death like a poor forsaken animal :'(.
Sounds like fuel is sloshing away from the fuel pickup OR the pickip is moving in the tank & air is getting in the system. This would explain why the opportunity is sensitive to braking & fuel level.
Copper is not the best material to use for the pickup as it fatigue cracks easily. Install a new steel tube to replace your old copper one. This won't cost too much - will it? ;)
Kyle,
I wish that you wouldn't have said that!!! We JUST installed a nice copper line into our tank (while it was out on the ground), for our Oasis heating system. I thought that copper would have been the best...Oh joy. Now I guess that we will see how long it lasts...Bummer. The pipe is installed from the top, so no way of replacing it, unless we pull the tank...
Oh, well. Thanks for the heads up.
God bless.
John
"They" used to use a double walled soft annealed copper for these things, but that was then . . . . I don't know if you can even get the stuff now, what with plastics taking over the flexable tubing market . . .
About leaking air into fuel line after the pick-up above the submerged fuel level....that would mean you have problem all the time...it is not problem because Phil said whenever low fuel level & hard braking only.
Phil...do what I suggested in previous post and problem is solved.
Sojourn for Christ, Gerald
Well Phil, you have some choices to choose from. . . . :o
Try what is easiest/ cheapest first, then progress up the scale of difficulty & expense as you are best able.
BTW, concerning having an air leak all the time & the problem manifesting during hard stops & low fuel in the tank . . . .
That is a typical symptom of a small leak. If the leak is small enough, it only renders the system marginal for normal running. But when you put the additional loads of hard braking & low fuel, the system can't keep up.
I've had the problem several times in the past. Amazing what a tiny air leak can do.
I can't imagine the 3/8" line is too big . . . . You are lifting the same volume of fuel regardless of the line size - the fuel moves faster in a smaller tube which leads to a higher pressure drop which can lead to problems on the suction side - especially if there is a small leak. ;)
If you're going to add a relief valve & return line, I'd locate the relief valve as close to the generator as possible - just like the factory did on the main engine.
Quote from: Sojourner on June 29, 2009, 04:31:56 AM
Phil....your problem is that you have too large pick-up tube. Why...the bigger tube inside dimension the more liquid/weight to lift and once the air entered while fuel's level is below pick-point during braking with the flow is too slow to fill up the inter displacement of extra large pick-up tube. You posted ½" in the earlier post.
Sojourn for Christ, Gerald
Gerald - MY MISTAKE!! Original post was wrong- for that I do apologize. My copper line is actually 3/8" Wrico said 5/16 was ideal, but usually 3/8 was OK - 1/2" would be BAD. Good to hear from you - I will also begin looking around for a reliefe valve - is there a line then from the relief valve back to the fuel tank?
We are going to review the flare fittings on the fuel line this weekend.
And - look at steel for the pickup. Didn't know the copper was bad! Wow! I'm learning lots of stuff here. And SOOOOOOOOO thankful for the heads up before I installed the WRONG check valve. What a hassle to go through just to find out that the generator would no longer function. Ouch!! I'm guessing steel can be purchased easily from an auto/truck parts store?
What is "cracking pressure" ? I've not heard that before . Thanks again!
Phil Lyons
Hey Phil,
Since that nasty ol' generator is causing you so much trouble, I'll be glad to take it off your hands if you want to drop in down here in Texas for a visit. Heck, I'd even be nice enough to loan you some tools to remove it. I might even serve you a nice cold adult beverage at no charge, just because I'm that kinda guy.
;D
Cracking pressure is the pressure required to 'crack' the valve off the seat & allow flow (but not full flow).
All the check valve will do is prevent the fuel from flowing back to the tank. Like when turned off for extended periods.
My understanding is the engine starts fine & is shutting down due to lack of fuel.
If fuel flow to the engine stops, the engine stops- unless you have some sort of reserve at the engine.
Just my opinion, but if you're having fuel delivery problems, adding another restriction (check valve) isn't likely to help.
A relief valve will require a return line to the tank. The original 2 stroke setup required the fuel return because the fuel was used to cool the injectors. Cars use a fuel return to help minimize vapor lock.
Again, I don't see this as a good solution to the current problem either - although it may the system may tolerate air better, it doesn't prevent it from entering in the first place.
If you want to use 5/16", Summit Racing has this:
http://www.summitracing.com/search/Part-Type/Tubing/Tubing-Outside-Diameter-in/5-16-in/?keyword=steel%20brake%20line
Good luck & keep us posted. . .
Kyle, he does have a return line to the tank on a Kubota, I for one still think it a shut solenoid problem you don't start one of these easy if air is in the system or it ran out of fuel,leads me to think it is shutting down at the pump.
The way mine works is 12 volts opens it to start 110V keeps it open for running.
I had this same problem with mine a while back replaced all the lines to the tank and it still would shut down so I did the old bungee cord repair to hold the solenoid open and it never shut down mine has the shut off on the side of the pump his may be in the pump. Or he could have a bad shutdown sensor telling the engine to shut down
good luck
Good point, I was assuming that possibility had been ruled out since he was looking for another solution (check valve).
Maybe a volt meter could be wired in to see what the solenoid is doing/ being told to do?
If that shows normal, maybe something can be rigged up to see if the solenoid is activating the shutdown without being told to . . . .
Quote from: Dallas on June 29, 2009, 11:29:17 AM
Hey Phil,
Since that nasty ol' generator is causing you so much trouble, I'll be glad to take it off your hands if you want to drop in down here in Texas for a visit. Heck, I'd even be nice enough to loan you some tools to remove it. I might even serve you a nice cold adult beverage at no charge, just because I'm that kinda guy.
;D
Dallas - you are "THE MAN"!!!! And - you were too modest to mention, that if I simply let you remove the generator - it won't be failing any more when the fuel level gets low. Totally Awesome!!! :D :D :D Ha Ha - I have sooo much to learn. ;D
Best Regards, Phil
He needs to disconnect his return line and check for air bubbles in the system the little engine will have a steady flow on the return if not he has a pickup problem and go from there. That would be my way of doing it
So, I have several suggestions it seems which suggest the fuel line w/in the tank or in the 6 inches outside the tank may have a very small hole, and this seems to be the least expensive option to try next, would this be the correct place to start? Can I put on steel tube fuel lines with flare fittings? Or? I know these are really basic questions, but I obviously don't mind humiliating myself in a public forum. :D
Then, if that checks out, I should move to diagnosing the solenoid or relief valve since those cost more and I could still have a hole in the fuel line? The copper fuel line is about 5 years old now.
Finally, it seems that the check valve would be treating a symptom. Am I correct?
Thanks again,
Phil,
I think you got it. I am assuming that you have already ruled out an electrical/shut down problem as discussed in the previous thread. The fact that moving the fuel pump closer to the tank helps, seems to agree with that. Unless replacing the fuel pick up is extremely difficult, I wouldn't sweat the copper vs steel at this time. Just do what is easiest until you have resolved the problem.
I'd do what luvrbus said about looking for bubbles in the return line first since it is easiest, just take the return line loose & let it flow into a fuel can. If air is present, you know an air leak is the problem. Unfortunately, all clear doesn't mean there isn't an air leak under braking tho . . . .
BTW, your copper lines may be fine & outlast the bus, I only mentioned that because they could be part of the problem & merit a look-see. ;)
Yes, the steel (& stainless) tubing can be used with flare fittings. I like the good ferrule fittings better tho. . . . But they are pricey . . .
http://www.grainger.com/Grainger/items/1WVR5
http://www.grainger.com/Grainger/wwg/productIndex.shtml?L2=Carbon+Steel+Compression+Tubing&operator=prodIndexRefinementSearch&originalValue=steel+tube+fittings&L1=Fittings%2C
Phil, rule out the relief valve because you don't have one on the Kubota return line it's only purpose is to dump unused fuel from the injectors back to the tank.If you are getting air in the system from a leak it will show on the return line in the form of bubbles.The way I check for bubbles is removing the return line and insert a short piece of clear plastic line with a connector and watch for bubbles works like a sight glass.
good luck
Quote from: luvrbus on June 29, 2009, 12:20:26 PM
Kyle, he does have a return line to the tank on a Kubota, I for one still think it a shut solenoid problem you don't start one of these easy if air is in the system or it ran out of fuel,leads me to think it is shutting down at the pump.
The way mine works is 12 volts opens it to start 110V keeps it open for running.
I had this same problem with mine a while back replaced all the lines to the tank and it still would shut down so I did the old bungee cord repair to hold the solenoid open and it never shut down mine has the shut off on the side of the pump his may be in the pump. Or he could have a bad shutdown sensor telling the engine to shut down
good luck
Phil...I wasn't sure that your Kubota already has a fuel return line...which means you don't need another one (relief valve or bleeder).
I would try what
luvrbus have done...it to see if it the
"shut down soleniod" is the cause of the shutting down when braking. I would temporary hold it open via cord or whatever and then road test it. If it keep running....then you need pin points from the schematic to see which sender unit or relay or loose connection. A fuel pressure sender unit can be out of calibration such as set too high of press before it energize the shut down soleniod. Or better yet call Wrico or whoever the manufacture support rep about the possible shut down system working during braking. They should know the where to check for the bad part
Sojourn for Christ, Gerald
I just remembered a PowerTech Generator (Kubota engine) that had a similar problem. I found a poor connection on the engine stop solenoid. The are 2 wires on this solenoid, one is the coil that activates the solenoid and the other is the "holding" coil. Both ground through the solenoid body to the engine. I removed OEM connections and soldered the wires directly to the solenoid. Jack
Jack, the adjustment on the units are very critical if not right on the money it will make the holding part not work all the time and eventually stop working all together fwiw been there done that good luck
Luvr,
I don't remember seeing any adjustment on the model I was working on, but I did not remove the solenoid from the engine. I replaced the bad spade terminal by soldering the wire directly to the terminal. Jack
Oh Good Grief! I just learned that soft copper has a different measurement scale than rigid copper. I thought they were the same - and I was WRONG!
Isn't this embarrassing!! :-[ :-[ Sorry for providing bad information.
I compared my fuel feed line w/in the fuel tank to some copper tubing I had, and measured & knew to be 1/2" - thus I "thought" my copper fuel line was 3/8 of an inch. I have since found out that actually, my fuel feed line is 1/2" soft copper. Waaay back in this thread, one of the first things said by Wrico & Others was that the fuel feed was supposed to be 3/8 to 5/16 inch line. And that too large of a fuel line would lead to loss of prime issues. I am assuming this measurement is in soft copper, not rigid.
Are there thoughts on using 1/2 inch fuel lines (soft) for pickup - e.g., is this too large? That would invalidate one of the underlying assumptions I presented.
If so, It looks like I need to replace the line w/ smaller diamater line - then see if I still have a problem. I had purchased some steel 5/16" line, but need to get new fittings. AS the bus is about to leave again on a trip, I have put everything back together.
Thanks again - and please accept my apologies for the bad measurements!
Phil