Mechanical pump fuel pressure.
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
Mechanical pump fuel pressure.
Is 62-63 alright at idle? I don't have a way right now to check under any other conditions. I expect it's enough but is it too much? I deleted the fuel bowl so I can adjust it. No tunes, stock injectors (for now 
)
EDIT: So the behavior is very different from cold to warmed up. The original question still stands but check out this difference in fuel pressure from cold to hot (video below). Cold the engine runs smooth and feels like it drives normally, hot it runs pretty rough and with fairly noticeable vibrations that you could call better or worse at different RPMs and a little unsettling to drive. Fuel level is above half way.
)EDIT: So the behavior is very different from cold to warmed up. The original question still stands but check out this difference in fuel pressure from cold to hot (video below). Cold the engine runs smooth and feels like it drives normally, hot it runs pretty rough and with fairly noticeable vibrations that you could call better or worse at different RPMs and a little unsettling to drive. Fuel level is above half way.
Hotshot
Joined: Aug 2006
Posts: 10,764
Likes: 39
Fuel Pressure is measured on the return to tank on an original fuel system . Not sure on your set up . 10 PSI at idle is enough to run smooth. If the engine runs rough when warm its usually Oil issues . When did you change the system ?
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
I changed it several months back because the fuel bowl was falling apart, and I prefer not having it clutter the valley. This is a standard regulated return configuration so it's measured on the pressure side.
I have replaced the injector orings and the high pressure hoses, but I haven't done the hpop.
Laughing Gas
Joined: Oct 2019
Posts: 949
Likes: 109
From: Fowler Colorado
You must be thinking of another motor fella. Stock fuel pressure is not measured at all. Not sure how measuring return pressure would tell anything either. But 60 psi at idle is about exactly what you want
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
This guy has the exact same setup I do and the pressure is doing the exact same thing when warmed up, so I'm not sure this actually indicates a problem. Might be normal for mechanical pumps.
That said, his engines isn't shaking like mine does. I think I need to try to get some ICP and IPR readings, maybe my HPOP is woofed.
Jump to the 8 minute mark
That said, his engines isn't shaking like mine does. I think I need to try to get some ICP and IPR readings, maybe my HPOP is woofed.
Jump to the 8 minute mark
Trending Topics
Laughing Gas
Joined: Oct 2019
Posts: 949
Likes: 109
From: Fowler Colorado
I never saw my pressure do that when I had a stock pump. Be best to get some readings tho for sure
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
I'm going to put an electric pump on it now. Still going to get my ICP and IPR readings as best I can, though I'm not going to try to take this thing WOT at 60mph. I think the tires are as vintage as the truck is. Hopefully some 2nd gear runs comparing cold to hot will give me an idea.
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
Alright, I got some data today and got a couple pulls over different temps from cold to completely warmed up. No tuning, stock injectors. As before idle and drive was much smoother cold than hot.
Run #1 - 3rd gear
Cold idle (slightly higher RPM I think):
Run #1 - 3rd gear
- Oil - 84 degrees
- ICP - 2,540 psi
- IPR - 34.7%
- Oil - 132 degrees
- ICP - 2,465 psi
- IPR - 35.16%
- Oil - 156 degrees
- ICP - 2,460 psi
- IPR - 35%
- Oil - 192 degrees
- ICP - 2460 psi
- IPR - 35%
Cold idle (slightly higher RPM I think):
- Oil - 70 degrees
- ICP - 710 psi
- IPR - 15%
- Oil - 198 degrees
- ICP - 580 psi
- IPR - 11.3%
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
After turning this around in my head for a bit I'm leaning more towards the idea that the injectors are blown out. When I pulled them to do injector cups all of them had less than .002" clearance. I ended up shimming them all, but that doesn't do a thing for the guts. The high pressure oil system can be healthy all day long but if the poppet valve with the bore in the injector is sloppy it's going to start working like crap as the oil gets hotter.
Lead Driver
Joined: Sep 2002
Posts: 9,540
Likes: 2,032
From: North Texas
Pressure at full load looks okay to me, the duty cycle...I forget what mine is as I do not look often, cannot comment. Idle duty cycle is higher than mine was, I think 8-10% from me...with fresh dropped to 5-7% I think.
Could you use a fresh pump? Probably if you did a tune and/or bigger sticks. Currently? Seems adequate.
You and I are in the same boat, I am pretty sure my injectors are done. 95% sure 160/30s for me.
Could you use a fresh pump? Probably if you did a tune and/or bigger sticks. Currently? Seems adequate.
You and I are in the same boat, I am pretty sure my injectors are done. 95% sure 160/30s for me.
Thread Starter
|
Cargo Master
Joined: Aug 2012
Posts: 2,863
Likes: 944
From: Kaufman TX
Pressure at full load looks okay to me, the duty cycle...I forget what mine is as I do not look often, cannot comment. Idle duty cycle is higher than mine was, I think 8-10% from me...with fresh dropped to 5-7% I think.
Could you use a fresh pump? Probably if you did a tune and/or bigger sticks. Currently? Seems adequate.
You and I are in the same boat, I am pretty sure my injectors are done. 95% sure 160/30s for me.
Could you use a fresh pump? Probably if you did a tune and/or bigger sticks. Currently? Seems adequate.
You and I are in the same boat, I am pretty sure my injectors are done. 95% sure 160/30s for me.
