lack of pressure

[Labhunter]

I have been experiancing a lack of pressure off and on for the last 3 weeks. More on than off. I keep adjusting the pump up and it goes up to the desired 60lb of pressure that I have been running, but then it begins to fall. It will level out around 50lb of pressure, but then will start to struggle to stay there and will again begin to drop to 45 then 40lb. If I adjust, it again will run around 60lb for a few miles and then begin to drop. Any ideas??

Dale
FASS adjustable pump.

[elrojo63]

I don't have any experience with the fass pumps but sounds like its getting weak. Does the pressure drop down just sitting at idle or just once you start driving it?


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[MtnOilRIG]

Just a few days ago I accidentally left my purge on for a few minutes and put a few gallons of diesel into about 25 gallons VO (15% accidental blend) and my FASS now easily stays right on 80 where I originally set it up. Until my brainfade purging, its been in the 74-78psi range and moved a lot more when gettin after it. Viscosity makes a difference with pressure regulation on the FASS, or so it seems.

Is there a viscosity issue going on in your scenario? New oil source?

[Labhunter]

Originally Posted by Labhunter

I have been experiancing a lack of pressure off and on for the last 3 weeks. More on than off. I keep adjusting the pump up and it goes up to the desired 60lb of pressure that I have been running, but then it begins to fall. It will level out around 50lb of pressure, but then will start to struggle to stay there and will again begin to drop to 45 then 40lb. If I adjust, it again will run around 60lb for a few miles and then begin to drop. Any ideas??

Dale
FASS adjustable pump.

I really guess I said it wrong. I have a valve that I use to set the desired pressure. That is what I have adjusted to open up the valve more to get more pressure. I haven't regulated the pressure on the pump any.

Yes, I can start the pump with the truck sitting still and it always starts with good pressure, but then backs off by 5 or 10 lbs.

I don't think it is the oil. It is the same oil that I have been using from the same restaurant and they have not changed the oil type.

I think I may have a leak, but can't find it.

[FASSAshley]

I would also recommend checking to see if the FASS will hold pressure while pulling fuel from a 5 gal bucket of diesel fuel. You can also crimp off the supply line and see if the pump coninues to build pressure or the pressure drops off. I would crimp the line and bump your starter to see if it builds pressure and maintains the pressure or if the pressure bleeds off with the line crimped. If the FASS holds pressure you know that you have a retriction down the line or somewhere up front that is causing the pressure drop. If you need any assistance you can all tech support at 636-433-5410. Thank you

[simone0414]

Could it be your gauge?? Does your gauge ready VO & D2 pressure? If so how's it working on D2?

My gauge has been messed up for a while. But it reads low on both fuels. It reads 35 PSI on D2 & 45 PSI on VO. I thought my purge valve was leaking by. But first I borrowed my buddy's fuel pressure tester & fuel pressure is fine. I have a cheap gauge & it had 50k miles on it. I have a new gauge just haven't taken the time to install it.

[Labhunter]

Originally Posted by simone0414

Could it be your gauge?? Does your gauge ready VO & D2 pressure? If so how's it working on D2?

My gauge has been messed up for a while. But it reads low on both fuels. It reads 35 PSI on D2 & 45 PSI on VO. I thought my purge valve was leaking by. But first I borrowed my buddy's fuel pressure tester & fuel pressure is fine. I have a cheap gauge & it had 50k miles on it. I have a new gauge just haven't taken the time to install it.

The gauge reads steady pressure on D2 but it will go from 70lb to 25 to 60 to 40 to 55, etc. moving all over the place when on vo. It is strange that it always starts with good pressure, but then falls off in a mile or so.

[Labhunter]

Originally Posted by FASSAshley

I would also recommend checking to see if the FASS will hold pressure while pulling fuel from a 5 gal bucket of diesel fuel. You can also crimp off the supply line and see if the pump coninues to build pressure or the pressure drops off. I would crimp the line and bump your starter to see if it builds pressure and maintains the pressure or if the pressure bleeds off with the line crimped. If the FASS holds pressure you know that you have a retriction down the line or somewhere up front that is causing the pressure drop. If you need any assistance you can all tech support at 636-433-5410. Thank you

I may be calling this week. I have to check several things before I get to that place though, I don't want to call before I have gone thru everything else.

Thanks

[Labhunter]

Ok, I believe I have found the problem. I really think it may have been a combo of two problems. I had a bad leak around the pick up on the top of the tank...it had become really bad in a fairly quick time frame. Fixed that. About the same time I changed my filters. I ran good pressure for about 20 miles or so and boom, pressure all over the place. I finally did the bucket test. I took the hose where it connects to the filter and disconnected it there. Good pressure. I changed the filter again and so far, good pressure. We will see what happens now. It could be that something just got in the filter and caused an obstruction, although my oil looks clean. The wind was blowing hard when I was fixing the leak and a leaf may have gone into the whole in the tank. I hope it is fixed and I'm back up and running now.