The Dreaded Lean Code

[Xjorgeypoox]

Aw

Yes it is

awesome.
So finally got the truck picked up after work. Hellish day...
Clutch feels great, almost feel like I need to learn to drive her again.
I don’t recall the exact numbers mechanic told me, but he verified the fuel pressure is weak. I’m assuming this means fuel pump is failing. So I went ahead and ordered the kemso. My buddy is sending me his Old fuel pump, so i can start the install of the new pump on the old sending unit. With this install, should I also replace the fpr while I’m at it? Would having a “stronger” pump put excess strain on the fpr? Or is it something I won’t need to be concerned with? Trying to line my ducks in a row before tackling this fuel pump.
Thanks guys!

 

[RonD]

On 1998 and up the FPR is usually in the fuel pump assembly

Picture here of assembly: https://www.jegs.com/images/photos/100/180/180-p74891s.jpg

Pump is of course at the bottom, you should clean the strainer or replace it if new pump doesn't come with one attached

Just above the pump is the FPR, round silver device, they are not connected
Fuel pump sends fuel out the top of the tank and to the fuel filter
Fuel filter will have 3 hoses instead of 2
The 3rd hose goes back to the top of the gas tank and then down to the FPR, then out of FPR to bottom of the tank

As far as I know you can not buy the FPR as a separate part, haven't looked that hard, or checked with Ford

If your 1999 only has a 2 hose fuel filter then there will be no FPR in the tank
It will be on the fuel rail at the engine, still a returnless system, one fuel line, but didn't work well and Ford stopped using it

 

[Xjorgeypoox]

On 1998 and up the FPR is usually in the fuel pump assembly

Picture here of assembly: https://www.jegs.com/images/photos/100/180/180-p74891s.jpg

Pump is of course at the bottom, you should clean the strainer or replace it if new pump doesn't come with one attached

Just above the pump is the FPR, round silver device, they are not connected
Fuel pump sends fuel out the top of the tank and to the fuel filter
Fuel filter will have 3 hoses instead of 2
The 3rd hose goes back to the top of the gas tank and then down to the FPR, then out of FPR to bottom of the tank

As far as I know you can not buy the FPR as a separate part, haven't looked that hard, or checked with Ford

If your 1999 only has a 2 hose fuel filter then there will be no FPR in the tank
It will be on the fuel rail at the engine, still a returnless system, one fuel line, but didn't work well and Ford stopped using it

Sweet. My fuel filter has 1 line so I’ve already concluded that it’s the returnless system.
I was just wondering if the higher rated pump would somehow damage the fpr forcing me to have to pull the pump out again in the future

 

[cbxer55]

On 1998 and up the FPR is usually in the fuel pump assembly

Picture here of assembly: https://www.jegs.com/images/photos/100/180/180-p74891s.jpg

Pump is of course at the bottom, you should clean the strainer or replace it if new pump doesn't come with one attached

Just above the pump is the FPR, round silver device, they are not connected
Fuel pump sends fuel out the top of the tank and to the fuel filter
Fuel filter will have 3 hoses instead of 2
The 3rd hose goes back to the top of the gas tank and then down to the FPR, then out of FPR to bottom of the tank

As far as I know you can not buy the FPR as a separate part, haven't looked that hard, or checked with Ford

If your 1999 only has a 2 hose fuel filter then there will be no FPR in the tank
It will be on the fuel rail at the engine, still a returnless system, one fuel line, but didn't work well and Ford stopped using it

Mine is a 98. It has a two hose filter. I have a new filter on the shelf.

 

[Xjorgeypoox]

Maybe I’m just over thinking it with the fpr? I’ve honestly never dealt with fuel pump issues lol

 

[cbxer55]

Maybe I’m just over thinking it with the fpr? I’ve honestly never dealt with fuel pump issues lol

I would just change the pump for now. It's highly unlikely the FPR is bad. Mine is 22 years old, shown no sign of being bad yet. I replaced my pump in January 2017 with a pump bought from Sears. Still going strong to this day.

 

[RonD]

Motorcraft fuel pumps are tested which is why they cost so much more than 3rd party pumps
Its the higher cost of labor now in a Quality control department
But Ford can't afford its higher labor cost to replace new fuel pumps on new vehicles so its worth it to them to pay extra upfront to have all the parts tested BEFORE they are installed

3rd party pumps are fine to use if you understand YOU are the Quality control department for the brand you chose, YOU are the first person to test it that part

For alot of parts, that are easy to swap out, saving money on a 3rd party brand is a no brainier, except IAC Valves, lol
But fuel pumps can be a pain to replace for most, so you need to decide what your time is worth to be the Quality control department for a 3rd party brand
Warranties are great but I would rather have a part that just works than a free replacement

If you get a 3rd party pump save the receipt, and make sure it has a roll-over, i.e. if its a 1 year warranty, and you need to replace it at 10months, the new replacement has 12 more months, not just the 2 months left on original pump

 

[Xjorgeypoox]

Motorcraft fuel pumps are tested which is why they cost so much more than 3rd party pumps
Its the higher cost of labor now in a Quality control department
But Ford can't afford its higher labor cost to replace new fuel pumps on new vehicles so its worth it to them to pay extra upfront to have all the parts tested BEFORE they are installed

3rd party pumps are fine to use if you understand YOU are the Quality control department for the brand you chose, YOU are the first person to test it that part

For alot of parts, that are easy to swap out, saving money on a 3rd party brand is a no brainier, except IAC Valves, lol
But fuel pumps can be a pain to replace for most, so you need to decide what your time is worth to be the Quality control department for a 3rd party brand
Warranties are great but I would rather have a part that just works than a free replacement

If you get a 3rd party pump save the receipt, and make sure it has a roll-over, i.e. if its a 1 year warranty, and you need to replace it at 10months, the new replacement has 12 more months, not just the 2 months left on original pump

While this makes perfect sense, I’m going the route of using the stock sender with just a new pump as others have said is the best way to go about this, without forking up a ton for a new ford part.
My concern is wether I need to try, it even possible to replace the fpr.
I’m just wondering what’s the probability or likely was that the new pump could or would cause the fpr to go bad, since the pump I’ve got coming is a higher rated pump.

 

[cbxer55]

What's a "higher rated pump?" The requirement for the 98 - 00 is 56 to 72 psi running. Why would you want to go beyond that? The new one I put in is putting out 62 psi, has been since I installed it. Runs awesome. No need to go beyond the stock requirements. I wouldn't want to without beefing up the entire fuel system to handle it. Guys on LightningRodder.com routinely run high output pumps. But they replace everything from the fuel; tank forward prior to doing so. Including the fuel rails, and they replace the FPR with an adjustable one.

I doubt the FPR is the problem. My pump went out in January 2017 while I was out driving. Still managed to drive it home with only 20 psi showing when I checked it. It drove, but would not accelerate briskly at all. Wouldn't accept heavy throttle, had to pussy-foot it home. For quite some time before it went out, it was barely making the minimum 56 psi, but still ran acceptably.

I didn't find it that difficult to change. I put the axle on stands, removed the wheels, removed the tailgate, removed the bumper, disconnected the fuel filler hose, undid the bed bolts and slid the bed back far enough to access the pump. Heck with dropping the tank. I've helped friends with Lightnings, and we did the exact same thing. Once or twice, for other reasons, the bed was completely removed. Something three people can do with a Lightning bed. Ranger bed, possibly two.

 

[Xjorgeypoox]

What's a "higher rated pump?" The requirement for the 98 - 00 is 56 to 72 psi running. Why would you want to go beyond that? The new one I put in is putting out 62 psi, has been since I installed it. Runs awesome. No need to go beyond the stock requirements. I wouldn't want to without beefing up the entire fuel system to handle it. Guys on LightningRodder.com routinely run high output pumps. But they replace everything from the fuel; tank forward prior to doing so. Including the fuel rails, and they replace the FPR with an adjustable one.

I doubt the FPR is the problem. My pump went out in January 2017 while I was out driving. Still managed to drive it home with only 20 psi showing when I checked it. It drove, but would not accelerate briskly at all. Wouldn't accept heavy throttle, had to pussy-foot it home. For quite some time before it went out, it was barely making the minimum 56 psi, but still ran acceptably.

I didn't find it that difficult to change. I put the axle on stands, removed the wheels, removed the tailgate, removed the bumper, disconnected the fuel filler hose, undid the bed bolts and slid the bed back far enough to access the pump. Heck with dropping the tank. I've helped friends with Lightnings, and we did the exact same thing. Once or twice, for other reasons, the bed was completely removed. Something three people can do with a Lightning bed. Ranger bed, possibly two.

Okay, well maybe I’m not fully understanding the workings of a pump. Here, I’ve been told to throw in the kemso 340 lph pump or motor whatever you want to call it, into the stock sending unit. So, if it is rated at 340 liters per hour, that doesn’t mean it’s going to simply pump 340 unless certain requirements are met? As in input from fpr and so on?
Reason being I’ve also seen in other forums and threads that quite a few people are running this pump in their stock sending unit as a replacement for a failed pump. I’m truly not trying to spend 7-800 on a whole new ford assembly, if possible.

 

[Dirtman]

You are correct the pump is only going to produce what the rest of the fuel system allows. Pumps are rated by volume not pressure. Higher volume does not equal higher pressure. The regulator will still create 65psi of pressure regardless of the volume of the pump.

 

[Xjorgeypoox]

You are correct the pump is only going to produce what the rest of the fuel system allows. Pumps are rated by volume not pressure. Higher volume does not equal higher pressure. The regulator will still create 65psi of pressure regardless of the volume of the pump.

Ahh okay. So now it makes sense.
So essentially, the pump has the POTENTIAL to pump 340 LPH, if the correct conditions were met. So in reality, it should be an adequate replacement to hopefully solve my fueling issue.
Makes perfect sense now! Well, hopefully soon, I’ll have everything going and everything running properly!

 

[RonD]

I don't think you can buy the in tank FPR separately, but never looked

 

[Xjorgeypoox]

I don't think you can buy the in tank FPR separately, but never looked

That’s the general consensus I’m getting.
I’ll be calling my local dealer and seeing if I can verify. If not then good thing I’ll soon have 2 pumps in case of future failure

 

[RonD]

For each 10 horse power you need 1 GPH or 2.6 LPH flow

So 200HP would need 2.6 x 20 = 52 LPH
300HP 2.6 x 30 = 78 LPH
500HP 2.6 x 50 = 130 LPH

That's the FLOW the engine needs AT the carb or injectors

Fuel pumps flow rate should be listed with 5/10psi(carb), 30/40psi and 50/60psi as those are the most common pressures used
And at 13.5volt, running vehicle is 13.5volt to 14.5volt, for racing vehicle with no alternator there can be a 12volt flow listed

As pressure goes up the pumps flow rate goes down, it doesn't drop all that much between 30 and 60psi

I think the EFI Rangers all used 90-110 LPH at 40psi, so were fine with 60psi change in 1998, Ranger engines were all well below the 300HP mark, lol
Even a V8 swap would work with stock pump, unless you were modifying the stock 302/5.0l V8

There is no benefit in using a higher flow pump than needed, the fuel line size also matters as well
But it doesn't hurt anything to use a higher flow pump