when ever i first bump her over, i an getting 12 lbs of pressure. then it decides to go to five, and thaen to zero. this is all at idle. could this be my isolater freaking out or do i need a new lift pump. help! im a starving student and scared.i cant afford a vp
fuel pressure
- Thread starter Tex56
- Start date
cdennyb
Full Access Member
mine tends to drop a bit when I have a dirty ol filter.
Check that first... then if a new clean one don't fix the problem... grin and bear it.
Check that first... then if a new clean one don't fix the problem... grin and bear it.
Whit
Registered User
I would really like to see yer signature so I know what ya got.
I am guessing from what you describe that you have a 98.5 -02 vintage
it sounds like you have a fuel pressure gage electrical
hook up a temporary gauge (mechanical) to varify
you may have an internal bypass (spillback) opening up inside yer lift pump causing this
I am guessing from what you describe that you have a 98.5 -02 vintage
it sounds like you have a fuel pressure gage electrical
hook up a temporary gauge (mechanical) to varify
you may have an internal bypass (spillback) opening up inside yer lift pump causing this
cdennyb
Full Access Member
I think it's an older version also, 12V model. But even at that the lift pump should be able to hold steady if the filter is good.
I agree with the bypass option thing opening prematurely.
good luck.
I agree with the bypass option thing opening prematurely.
good luck.
cdennyb
Full Access Member
lift pump gone, adapter on.
I have an 03 ISB Cummins and decided to eliminate the lift pump because it's almost impossible to blow fuel thru the damn thing when they quit workin!
The pump(s) I use are under the truck and push around 150 gph @ 15 psi. With those kinds of flow numbers, the lift pump restricts the flow to almost nothin so I fabricated this little jewel to replace it so I could keep the filter housing with the water sensor thing in it. I like it.
So here's a few pics of the item.
I have since had waterjet cut me some 4 bolt flat plates so I can make a better, more rigid version that I won't have to worry about, ever!
I can sell these plates and the draawings to whoever wants to fab up one for their truck (engine) for pretty much cost. They're 3/16 stainless and perfect.
Let me know with a PM.
db
I have an 03 ISB Cummins and decided to eliminate the lift pump because it's almost impossible to blow fuel thru the damn thing when they quit workin!
The pump(s) I use are under the truck and push around 150 gph @ 15 psi. With those kinds of flow numbers, the lift pump restricts the flow to almost nothin so I fabricated this little jewel to replace it so I could keep the filter housing with the water sensor thing in it. I like it.
So here's a few pics of the item.
I have since had waterjet cut me some 4 bolt flat plates so I can make a better, more rigid version that I won't have to worry about, ever!
I can sell these plates and the draawings to whoever wants to fab up one for their truck (engine) for pretty much cost. They're 3/16 stainless and perfect.
Let me know with a PM.
db
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Whit
Registered User
thats cool......so what ya run for a pump now? Walbro?
cdennyb
Full Access Member
cdennyb
Full Access Member
Holley "Black Pumps"
At first you might think that because you have no idea what pump is in those "BLUE PUMP BRACKETS" but trust me, those are the Black versions that are rated at 140+ GPH. Anyway, I have a dozen different Holley pumps laying around and lots of crappy burned up pieces too, so I threw together what I had to make it work. In case of any problemsx, I could throw in a single blue pump but in my past experience, they don't hold up in the long run of continous duty pumping the heavier fuel vs gasoline.
I've never had any trouble starting my rig and I run between 25-30 psi to the Injector Pump. So, if high pressure caused hard starting, I would think I'd have a problem.
Keep in mind there's a return flow valve also to keep that primary pressure under control to a degree. I don't think the Fass pumps are any different basically than what I have. Maybe a few small design differences but on a flow sheet, where it really counts, it's all about volume and psi.
At first you might think that because you have no idea what pump is in those "BLUE PUMP BRACKETS" but trust me, those are the Black versions that are rated at 140+ GPH. Anyway, I have a dozen different Holley pumps laying around and lots of crappy burned up pieces too, so I threw together what I had to make it work. In case of any problemsx, I could throw in a single blue pump but in my past experience, they don't hold up in the long run of continous duty pumping the heavier fuel vs gasoline.
I've never had any trouble starting my rig and I run between 25-30 psi to the Injector Pump. So, if high pressure caused hard starting, I would think I'd have a problem.
Keep in mind there's a return flow valve also to keep that primary pressure under control to a degree. I don't think the Fass pumps are any different basically than what I have. Maybe a few small design differences but on a flow sheet, where it really counts, it's all about volume and psi.
cdennyb
Full Access Member
Updated the pump replacement brkt.
Here's acoupleof pictures of the new flat plates and the 1/2" stainless tubing feeding the filter housing. I just did the original late one night with scraps I had laying around and these plates are actually laser cut, I was asking for waterjet 'cause it was cheaper but the machine was being used on a big job so in order to meet their promised deadline of delivery they cut it with the laser.
Here's acoupleof pictures of the new flat plates and the 1/2" stainless tubing feeding the filter housing. I just did the original late one night with scraps I had laying around and these plates are actually laser cut, I was asking for waterjet 'cause it was cheaper but the machine was being used on a big job so in order to meet their promised deadline of delivery they cut it with the laser.
