1999 Ranger 2.5 Fuel Pressure Specs
#2
Welcome to the forum
1998 and up Rangers use 55-65psi fuel pressure at the engine
There is a test port on the engines Fuel Rail, its a tube that connects to each fuel injector on the intake side of engine, drivers side
Test port is a schrader valve, same as the valve on a tire to add or remove air from the tire
Test port should have a screw on cap, same as a tires air valve, but may have been removed and not replaced, cap doesn't hold pressure just there to keep port clean, same as air valve cap
You test pressure the same way you would with tire pressure, but gauge needs to have screw on type hose and OK for liquid
After gauge is installed start engine
Should see 55-65psi
Raise RPMs to 2,500 or so, and hold it there for a minute or so, pressure should hold, if its slowly dropping then there is an issue with filter(clogged up) or pump, getting weak
Shut off engine
Pressure should drop a bit but should stay above 20-30psi for MONTHS and MONTHS
If pressure drops to 0psi over a few minutes then pumps check valve or Fuel Pressure Regulator(FPR) is bad, BOTH are in the gas tank, part of fuel pump assembly
1998 and up Rangers use 55-65psi fuel pressure at the engine
There is a test port on the engines Fuel Rail, its a tube that connects to each fuel injector on the intake side of engine, drivers side
Test port is a schrader valve, same as the valve on a tire to add or remove air from the tire
Test port should have a screw on cap, same as a tires air valve, but may have been removed and not replaced, cap doesn't hold pressure just there to keep port clean, same as air valve cap
You test pressure the same way you would with tire pressure, but gauge needs to have screw on type hose and OK for liquid
After gauge is installed start engine
Should see 55-65psi
Raise RPMs to 2,500 or so, and hold it there for a minute or so, pressure should hold, if its slowly dropping then there is an issue with filter(clogged up) or pump, getting weak
Shut off engine
Pressure should drop a bit but should stay above 20-30psi for MONTHS and MONTHS
If pressure drops to 0psi over a few minutes then pumps check valve or Fuel Pressure Regulator(FPR) is bad, BOTH are in the gas tank, part of fuel pump assembly
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B Series (02-23-2022)
#3
Actually I figured out how to do this.
The pressure was 66 PSI with the car running.
I turned the car off and let it sit for 1 hour; the pressure dropped to 30 PSI.
After 2 hours the pressure was 0 PSI.
Under partial throttle; the truck will hesitate at times (full throttle is ok).
I was able to make the truck hesitate under light throttle when the fuel pump tester was on the car and the fuel
pressure only dropped to 64 PSI.
So I guess I have a leaking injector or a bad check valve in the gas tank.
FYI, the truck is throwing no trouble codes.
Also I just COMPLETELY tuned it up with Motorcraft parts (plugs, wires, pcv, fuel filter, air filter).
Any thoughts?
Thank you !!
The pressure was 66 PSI with the car running.
I turned the car off and let it sit for 1 hour; the pressure dropped to 30 PSI.
After 2 hours the pressure was 0 PSI.
Under partial throttle; the truck will hesitate at times (full throttle is ok).
I was able to make the truck hesitate under light throttle when the fuel pump tester was on the car and the fuel
pressure only dropped to 64 PSI.
So I guess I have a leaking injector or a bad check valve in the gas tank.
FYI, the truck is throwing no trouble codes.
Also I just COMPLETELY tuned it up with Motorcraft parts (plugs, wires, pcv, fuel filter, air filter).
Any thoughts?
Thank you !!
#4
Fuel pressure would have to drop ALOT lower to cause hesitation
Fuel specs are 55-65psi so you would have to see a drop, while running, to under 35psi to feel any effect
Fuel pressure SHOULD drop when accelerating, 5psi usually but up to 10psi is fine
The key off and drop to 0psi may cause hard cold start, nothing more, and unless MPG has dropped way way down, you don't have a leaking injector
Usually check valve or regulator in gas tank is leaking, so no fuel lost, just pressure
Fuel specs are 55-65psi so you would have to see a drop, while running, to under 35psi to feel any effect
Fuel pressure SHOULD drop when accelerating, 5psi usually but up to 10psi is fine
The key off and drop to 0psi may cause hard cold start, nothing more, and unless MPG has dropped way way down, you don't have a leaking injector
Usually check valve or regulator in gas tank is leaking, so no fuel lost, just pressure
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B Series (02-23-2022)
#5
I did the leaking injector test.
Attempted to start the truck with the gas pedal to the floor.
The truck would not start so you are absolutely correct....no leaking injectors.
I am going to replace the entire fuel pump hanger assembly next weekend (Delphi HP 10229) which should hopefully fix this.
And yes, it's really hard to start after the truck has been sitting for a few hours.
Attempted to start the truck with the gas pedal to the floor.
The truck would not start so you are absolutely correct....no leaking injectors.
I am going to replace the entire fuel pump hanger assembly next weekend (Delphi HP 10229) which should hopefully fix this.
And yes, it's really hard to start after the truck has been sitting for a few hours.
#8
Thank you RonD 2022 & having similar problem. Changed the fuel pump (can't remember how long ago.). Researching fuel pump assemblies before I order a new one; ( running a 2000 Mazda B2500 labelled Ranger standard M/T). My old pump assembly has an enclosed little brown barrel kind of a battery looking thing, in one of the holes of the assembly cap and all the ones I've looked at don't have that and I don't know what's that component's function? Are the assemblies I'm looking at so updated or refined they've replaced the part with something more efficient?
Also what's the difference between 3 port fuel pumps vs 2 port fuel pump assembly? While reading about Fuel Pump Assemblies, noticed they're all manufactured in China for American after market brands to confuse choosing further. So I decided what I really need to know is how all the Assembly components work and the specs this 2.5L l4 engine requires to function optimally. In addition some of the Assemblies being sold describe not having wiring harness?! WTH does that mean? Is there a engine specific fuel pump assembly impartial technical buying guide?
Also what's the difference between 3 port fuel pumps vs 2 port fuel pump assembly? While reading about Fuel Pump Assemblies, noticed they're all manufactured in China for American after market brands to confuse choosing further. So I decided what I really need to know is how all the Assembly components work and the specs this 2.5L l4 engine requires to function optimally. In addition some of the Assemblies being sold describe not having wiring harness?! WTH does that mean? Is there a engine specific fuel pump assembly impartial technical buying guide?
Last edited by B Series; 02-23-2022 at 01:19 PM.
#9
From 1989 and up Ranger pumps were the same, engine size never mattered
1989-1997 had 2 fuel lines and Fuel Pressure Regulator(FPR) on the engine, 2 port fuel filter
1998-2000 had 1 fuel line, FPR on the assembly, 2 port fuel filter
2001-2011 has 2 fuel lines, FPR on assembly, 3 port filter
1989-1997 Ranger Computers were programmed to expect 35psi fuel pressure
1998-2011 Ranger Computers were programmed to expect 60psi fuel pressure
There was never a Fuel Pressure Sensor
Pressure at each injector needs to be correct or computers calculations will be wrong, +/- 8psi is OK
Fuel pumps are either tested or not tested at the factory when made and boxed
Tested costs alot more, like Motorcraft pumps
Untested costs alot less, but come with longer warranties, untested is untested don't think brand matters
3rd party brand assemblies usually have springs on the supporting rods to they can fit different size gas tank depths
Motorcraft assemblies are tank size specific, Rangers had 17gal or 20gal tank sizes
Regular cab 17gal
Extended cab 20gal
"Long Bed", 20gal
The 2001-2011 2 hose setup was better than the 1 hose 1998-2000, and you can switch to that but you do need the extra fuel line from a 2001 and up and the 3 port filter
Not really a big enough difference to switch, IMO, but up to you
Assemblies have a 4 wire connector, 2 wires for sender(gas gauge) and 2 wires for the pump
There can be other wires for the EVAP systems sensors and valves
1989-1997 had 2 fuel lines and Fuel Pressure Regulator(FPR) on the engine, 2 port fuel filter
1998-2000 had 1 fuel line, FPR on the assembly, 2 port fuel filter
2001-2011 has 2 fuel lines, FPR on assembly, 3 port filter
1989-1997 Ranger Computers were programmed to expect 35psi fuel pressure
1998-2011 Ranger Computers were programmed to expect 60psi fuel pressure
There was never a Fuel Pressure Sensor
Pressure at each injector needs to be correct or computers calculations will be wrong, +/- 8psi is OK
Fuel pumps are either tested or not tested at the factory when made and boxed
Tested costs alot more, like Motorcraft pumps
Untested costs alot less, but come with longer warranties, untested is untested don't think brand matters
3rd party brand assemblies usually have springs on the supporting rods to they can fit different size gas tank depths
Motorcraft assemblies are tank size specific, Rangers had 17gal or 20gal tank sizes
Regular cab 17gal
Extended cab 20gal
"Long Bed", 20gal
The 2001-2011 2 hose setup was better than the 1 hose 1998-2000, and you can switch to that but you do need the extra fuel line from a 2001 and up and the 3 port filter
Not really a big enough difference to switch, IMO, but up to you
Assemblies have a 4 wire connector, 2 wires for sender(gas gauge) and 2 wires for the pump
There can be other wires for the EVAP systems sensors and valves
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B Series (02-23-2022)
#10
Would you please recommend a fuel pump assembly, price range that is acceptable, safe online buying point. I have a FPR on the fuel rail but can't find a replacement. So is there a second FPR in the fuel tank? I picked up a pick and pull fuel rail with everything on it from a wrecked truck w/ 28000 miles on it, to clean up as a spare.
Appreciate your helpful informative time.
Appreciate your helpful informative time.
#11
Would you please recommend a fuel pump assembly, price range that is acceptable, safe online buying point. I have a FPR on the fuel rail but can't find a replacement. So is there a second FPR in the fuel tank? I picked up a pick and pull fuel rail with everything on it from a wrecked truck w/ 28000 miles on it, to clean up as a spare.
Appreciate your helpful informative time.
Appreciate your helpful informative time.
1998 and up have FPR in the gas tank
Motorcraft is the only fuel pump assembly that can be recommended
Others can suggest other brands they have tried and is still working
On the 1998 and up some people mistake the Pulse Damper on the engine for an FPR, it isn't, it has a vacuum hose connected, no fuel return line, so not an FPR
The following users liked this post:
B Series (02-23-2022)
#12
Last online mazda oem listed almost everything I order as discontinued by mazda & ford, the Plemum Gasket set I ordered has been processing for a week now. Motorcraft is not available directly to customers. One online mazda ford parts dealer quoted $529. for an electric fuel pump. Some places don't even list vehicles older than 2014 Where do you get new motorcraft parts for old vehicles?
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