jrsavoie
Recruit
You might want to add a sender before the filter also.
He OEM lift pumps aren't known for supplying ample fuel.
Especially if you buy aftermarket, OEM style
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
Engine RPMs revving while driving
- Thread starter mhixson
- Start date
He OEM lift pumps aren't known for supplying ample fuel.
Especially if you buy aftermarket, OEM style
mhixson
Member
What type of sender would that be? I don't think I understand what you're suggesting.
mhixson
Member
And here's that same jar of fuel after sitting in the dark in my shop for almost two weeks. Doesn't look a bit different to me.
Attachments
Will L.
Well-Known Member
Correct- the fuel looks perfect. Good that you don’t have algae in the fuel or other garbage. But sunlight makes them grow more not darkness.
Yes the filter could be plugged but I really doubt it. You could open it up and inspect to see of the new one plugged up.
Be sure you check the small center filter ak diesel driver mentioned. That can plug up and be a problem all by itself. As dirty as the first filter was, it wouldn’t surprise me. Here is what they are. You almost never have to replace these, they rinse of with fuel, but not like they are expensive. Basically smaller diameter than your pinky finger.
leroydiesel.com
Really make sure the fuel line you are reading the pressure from is inbetween the ffm and ip. It should not be but someone could have changed it. Make sure to follow the line. And you might need to replace the rubber fuel line if the previous owner didn’t do it yet.
Even so- 5psi is not good even if it maintains 5 psi when you drive. 8-14 is the range suggested by stanandyne (ip manufacturer). Long term the best answer isn’t fun or cheap. Get a Fass lift pump with filter system. Mount it just infront of the passenger side tail light behind the rock shield. You have to run some new fuel lines to do this obviously. Electric running to it as well. Eliminate the factory barely adequate ffm and eliminate the wholly inadequate factory lift pump.
There is guys on HML that have installed that pump in that location, worked out really well. The much much larger fuel filter and water separator filter means instead of doing a fuel filter every 10,000 miles you probably go 40,000 miles between changes. If you live in a cold area where fuel heater is needed Fass sells one that goes into it. This is a descent task for new diy people- if over your head then modern diesel shops can do this no problem. Replacing all the original rubber lines with sae30r9 done at same time. The old lines don’t withstand the modern fuel- and deteriorated hoses could be your problem right now. The only way to know is getting that fitting I showed and read the gauge tapped from there while you drive it.
The fuel pressure gauge being mounted permanently in the dash is huge because whenever there is a hiccup you know instantly if it is a fuel problem. Low fuel pressure ruins the ip. You also might be fighting a very worn out ip because of it.
With clean fuel at proper pressure- the ds4 ip is usually good for 250,000-300,000 miles. Running clean fuel but going into vacuum instead of pressure on the fuel line I have seen brand new ip ruined in 20,000 miles beyond rebuilding capacity.
There is a serious reason I push the gauge so hard. Not like I make money off people installing them- I just hate seeing people kill their engines when the fix is simple.
As to the second sensor mentioned- this is what I am doing on my current build.
Have a sensor at the ip in the adapter fitting I showed. Then another sensor onnthe incoming side of the fass fuel filter. Run wire from each to a switch and the output of the switch to the gauge. So switch in position 1 I see the pressure at the ip. When I want to know when filter needs to be changed flip switch to the other sensor and read incoming pressure. Seeing the larger differential in pressure will indicate when the filter is needing replaced. It will take some time to learn that pressure but then it eliminates replacing too soon or too late. This isn’t critical just a convenience thing. 8-14 psi at ALL TIMES is critical.
If you look around for a different lift pump- speak up before you buy. The factory design (type) a bunch of us did comparison testing and the best one is the AC Delco EP158. They are like $100 and you will barely hit 8psi at best. Then replace it every 2 years. Long term if you are going to put 60,000 miles on the rig it is cheaper to get the Fass system.
Right now because of what we already see whats been happening- double the dosage of your fuel lube additive.
Yes the filter could be plugged but I really doubt it. You could open it up and inspect to see of the new one plugged up.
Be sure you check the small center filter ak diesel driver mentioned. That can plug up and be a problem all by itself. As dirty as the first filter was, it wouldn’t surprise me. Here is what they are. You almost never have to replace these, they rinse of with fuel, but not like they are expensive. Basically smaller diameter than your pinky finger.
Leroy Diesel
Really make sure the fuel line you are reading the pressure from is inbetween the ffm and ip. It should not be but someone could have changed it. Make sure to follow the line. And you might need to replace the rubber fuel line if the previous owner didn’t do it yet.
Even so- 5psi is not good even if it maintains 5 psi when you drive. 8-14 is the range suggested by stanandyne (ip manufacturer). Long term the best answer isn’t fun or cheap. Get a Fass lift pump with filter system. Mount it just infront of the passenger side tail light behind the rock shield. You have to run some new fuel lines to do this obviously. Electric running to it as well. Eliminate the factory barely adequate ffm and eliminate the wholly inadequate factory lift pump.
There is guys on HML that have installed that pump in that location, worked out really well. The much much larger fuel filter and water separator filter means instead of doing a fuel filter every 10,000 miles you probably go 40,000 miles between changes. If you live in a cold area where fuel heater is needed Fass sells one that goes into it. This is a descent task for new diy people- if over your head then modern diesel shops can do this no problem. Replacing all the original rubber lines with sae30r9 done at same time. The old lines don’t withstand the modern fuel- and deteriorated hoses could be your problem right now. The only way to know is getting that fitting I showed and read the gauge tapped from there while you drive it.
The fuel pressure gauge being mounted permanently in the dash is huge because whenever there is a hiccup you know instantly if it is a fuel problem. Low fuel pressure ruins the ip. You also might be fighting a very worn out ip because of it.
With clean fuel at proper pressure- the ds4 ip is usually good for 250,000-300,000 miles. Running clean fuel but going into vacuum instead of pressure on the fuel line I have seen brand new ip ruined in 20,000 miles beyond rebuilding capacity.
There is a serious reason I push the gauge so hard. Not like I make money off people installing them- I just hate seeing people kill their engines when the fix is simple.
As to the second sensor mentioned- this is what I am doing on my current build.
Have a sensor at the ip in the adapter fitting I showed. Then another sensor onnthe incoming side of the fass fuel filter. Run wire from each to a switch and the output of the switch to the gauge. So switch in position 1 I see the pressure at the ip. When I want to know when filter needs to be changed flip switch to the other sensor and read incoming pressure. Seeing the larger differential in pressure will indicate when the filter is needing replaced. It will take some time to learn that pressure but then it eliminates replacing too soon or too late. This isn’t critical just a convenience thing. 8-14 psi at ALL TIMES is critical.
If you look around for a different lift pump- speak up before you buy. The factory design (type) a bunch of us did comparison testing and the best one is the AC Delco EP158. They are like $100 and you will barely hit 8psi at best. Then replace it every 2 years. Long term if you are going to put 60,000 miles on the rig it is cheaper to get the Fass system.
Right now because of what we already see whats been happening- double the dosage of your fuel lube additive.
ak diesel driver
6.5 driver
So wee need to know exactly where those hoses are coming from. If it still has the stock fuel filter manager (FFM), did the smaller nipple get plugged off, and does the hose going to that funky fitting go to the larger nipple on the FFM? Did you check and see if there's a screen around the tube in the middle of the FFM? It will be at the bottom. If it's dirty it could cause low fuel pressure. If all that is intact like it should be, it's time for a new lift pump (LP).
dbrannon79
I'm getting there!
What lift pump do you have installed now. 5psi key on and 0 ideling sounds like the LP is fubar. Like others have said. the delco EP158 is the best out of the factory pumps, but if you want a long life out of your IP. get something that can keep up with the demand of the iP. someting that is rated ay 8-14 psi and has at least a 50gph rating for flow. I bought one that was only rated for 30 gph and it's not enough when under full load, but driving normally is will maintain 3-5 psi.
MrMarty51
Well-Known Member
I bought the Leroy Diesel relay/pump kit. It came with the Carter pump. I dont remember what that pump is rated at for pressure or volume.
Pulling the steepest hill between home and church, and it is steeeeep, the fuel pressure never dropped to less than 9 PSI.
Years ago I had run Carter electronical pumps on various conversions and they seemed to supply ample fuel and pressure. That was on the carbed trucks and cars though.
I have not read any bad about the Carter brands on the Leroy systems.
Pulling the steepest hill between home and church, and it is steeeeep, the fuel pressure never dropped to less than 9 PSI.
Years ago I had run Carter electronical pumps on various conversions and they seemed to supply ample fuel and pressure. That was on the carbed trucks and cars though.
I have not read any bad about the Carter brands on the Leroy systems.
mhixson
Member
Someone relocated it then. That originally went between the ffm and the drain.
Is so, fine. Just replace tje fuel line from there to the ip inlet with new sae30r9 hose because the original hose throttle the rig fails under the ethanol fuel we have now. If the hose after that schrader valve fails internally- you won’t know and again would think pressure is good when it is restricted.
Search the picture from warwagon- his was a classic example. Seen so many people buy new ip replacing good ones because the fuel line fails inside.
Doing that will tell you the pressure now. Rig the hose so you can read the gauge while driving. Jammed under the windshield wiper is a common move for that. Idle and revving the engine while sitting still will barely cause a draw. Truck under heavy acceleration going up a hill is a completely different level.
Long term
Buy this:
Then choose an electronic fuel pressure gauge with compact sending unit.
Fuel Pressure Gauge Adapter
A fuel pressure gauge is essential to monitoring the health of your fuel delivery system. Mod Mafia makes it easy to add this important gauge to your Hummer / H1…modmafia.com
Tad on HML had one done at speedhut that replaced the clock in the dash that always fails. His turned out looking very stock.
To install this adapter do I unthread the barbed fitting from my IP, thread the Mod Mafia adapter into the IP, and then thread the IP's barbed fitting into the Mod Mafia part?
And when you don't have a pressure sending unit or pressure tester attached to this, what plugs the hole in it?
Will L.
Well-Known Member
Yes. 1/8” npt plug would seal it but I wouldn’t put it in until you get the sending unit (usually in a kit with gauge).
Getting a gauge permanently mounted in the dash is key. You see the pressure and will notice when there is a drop in pressure. This indicates when to check things out, rather than waiting until something breaks down or does damage.
Getting a gauge permanently mounted in the dash is key. You see the pressure and will notice when there is a drop in pressure. This indicates when to check things out, rather than waiting until something breaks down or does damage.
Running out of fuel does weird stuff like revving.
Flapper in hose. Your pressure gauge should also read vacuum. I have had these engines "Vapor Lock" pulling against a restriction like clogged tank sock or a softened hose that kinked shut.
Tank lining coming off clogging tank sock.
Flapper in hose. Your pressure gauge should also read vacuum. I have had these engines "Vapor Lock" pulling against a restriction like clogged tank sock or a softened hose that kinked shut.
Tank lining coming off clogging tank sock.