10 mpg

[HakunaMatata]

Hello,

2011 ford ranger xlt 300,000 miles, On my second engine second trans. Engine blew from Crack in valve gully allowing valve to move around, then break, then have an orggy with the piston. Trany went bad with a bad pump, so just had it rebuilt. I've owned this truck since 46k miles. Use it for pool service business, yup replaced 3 beds and welded frame. She still going though.

Her fuel mileage has been getting worse over the last year. I've changed many parts, many of them several times since owning. Ive had a rich environment for years, to the point it was going through cats each year, finally just gutted them and did the spark plug anti fouler trick on the secondary 02's. She never dropped below 15 mpg. I keep up on service and do most maintenance early, like plugs, filter, and wires etc. She is now getting really bad, 10 mpg, I can tell she's dumping fuel at lower rpm, she hesitates, looses power, and smells of straight gas at idle and under 2k rpm. Above 2k she's fine, can handle the extra gas.

While always searching for a cause, I found the pulse dampened. Well it's not there. No where to be found on the fuel rail. The vacuum line on the intake T is capped off. Now I'm back to no idea what it could be.

Recently changed map sensor, plugs, wires, brake booster, iac, fuel filter, air filter, clutch fan, coil, secondary 02's, oil, trans fluid and filter, and a lot of suspension parts.

I have pulse dampener, water pump, egr, cps, electric fans, starter, motor mounts, trany mount, u joints, altenator, power steering pump and lines, complete thermostat housing (one on truck has 1 temp sensor and 1 connector - new one has 2 sensors, don't see another connector for the second sensor), belt, and probably a couple other parts in my shop to replace if needed.

But I don't know where or what to replace at this point. I had a compression test about a year ago, they said it came back perfect, they said, not sure they actually did it. I'm not getting any codes what so ever. No rich code, no lean code, no parts bad code.

I will be changing the egr this weekend. Other than that I have no idea. I thought for sure it was the pulse dampener, but it's no where to be found.

Any help is much appreciated!

 

[RonD]

Welcome to TRS

Yes, around 2007 Ford dropped the Temp Sender(for dash temp gauge) on the 4.0l's thermostat housing, just has the ECT sensor, so just needs the one hole
You can get a new ECT sensor and use the old one to plug the hole in the new housing

The dash temp gauge is now run by computer using ECT sensor data, just FYI

Missing Damper would be a stretch to cause big drop in MPG, its only there to lessen pulse waves in fuel rail
Vacuum hose was there to prevent fires in case Damper leaked, wasn't part of Damper function

You can't have 10MPG and not have Rich codes
So either 10MPG is a user or odometer issue, lol
OR you are leaking fuel out of tank or fuel line
(neighbour kid with siphon hose )
Or Computer has lost its mind

Pull a spark plug, if it is not dark brown or black then you are not running Rich
So neighbour kid or a leak
If it is then its running Rich and computer is the issue

There is a "Clear Flooded Engine" mode in all fuel injection computers
It shuts off computer injector pulses to Clear a Flooded Engine, lol
Key on engine off
Press gas pedal down to the floor, all the way, hold it down
(Computer sees 0 RPMs and WOT(wide open throttle) so it enters Clear Flooded Engine mode)
Crank engine
It should NOT start, it should not fire, no fuel, this would "dry out" a flooded engine
If it starts then you may have a leaking injector, but would get Rich code on that Bank of engine


If it started.........it may be because throttle cable is stretched, so computer didn't "see" WOT
Use a stick against the seat to push gas pedal down all the way
Go to the engine and see if you can manually open the throttle more
If so
Google: Ranger Throttle Cable Mod
Simple fix
Then redo the test

 

[alwaysFlOoReD]

You mentioned replacing the secondary o2's. Waste of time if you gutted the cats. Have you changed the primary o2's? They wear out after 100,000 miles or 10 years. Only sensor that wears out...

 

[HakunaMatata]

Welcome to TRS

Yes, around 2007 Ford dropped the Temp Sender(for dash temp gauge) on the 4.0l's thermostat housing, just has the ECT sensor, so just needs the one hole
You can get a new ECT sensor and use the old one to plug the hole in the new housing

The dash temp gauge is now run by computer using ECT sensor data, just FYI

Missing Damper would be a stretch to cause big drop in MPG, its only there to lessen pulse waves in fuel rail
Vacuum hose was there to prevent fires in case Damper leaked, wasn't part of Damper function

You can't have 10MPG and not have Rich codes
So either 10MPG is a user or odometer issue, lol
OR you are leaking fuel out of tank or fuel line
(neighbour kid with siphon hose )
Or Computer has lost its mind

Pull a spark plug, if it is not dark brown or black then you are not running Rich
So neighbour kid or a leak
If it is then its running Rich and computer is the issue

There is a "Clear Flooded Engine" mode in all fuel injection computers
It shuts off computer injector pulses to Clear a Flooded Engine, lol
Key on engine off
Press gas pedal down to the floor, all the way, hold it down
(Computer sees 0 RPMs and WOT(wide open throttle) so it enters Clear Flooded Engine mode)
Crank engine
It should NOT start, it should not fire, no fuel, this would "dry out" a flooded engine
If it starts then you may have a leaking injector, but would get Rich code on that Bank of engine


If it started.........it may be because throttle cable is stretched, so computer didn't "see" WOT
Use a stick against the seat to push gas pedal down all the way
Go to the engine and see if you can manually open the throttle more
If so
Google: Ranger Throttle Cable Mod
Simple fix
Then redo the test

My thought on dampener causing this was fuel getting sucked into intake due to failure, but its not there.

Im deffenitly not leaking fuel and 100% positive no one is stealing it. I use this truck for business, and im very busy. I drive anywhere from 100-175 miles a day. I fill up every 2 days, sometimes within 30 hours. I have calculated the amount of fuel burned on every tank over the last month, average of 10-12mpg, verified my miles via google maps gps, odometer is right.

I am not getting codes, none. If thats impossible unless the computer is toast, then i guess it is, because im not getting any codes at all. I will deffenitly be trying the wot test.

 

[HakunaMatata]

You mentioned replacing the secondary o2's. Waste of time if you gutted the cats. Have you changed the primary o2's? They wear out after 100,000 miles or 10 years. Only sensor that wears out...

Through the life of the vehicle ive changed the front 02's several times. Last time was when i changed the cats for the second time, which was about 1.5 years ago, or around 50-60k miles ago. I will just go ahead and replace them again for the hell of it, but history with this truck it has always thrown codes for bad ones. The only reason the secondaries got changed is due to gutting the cats, the where both throwning codes before i gutted them and wouldnt go away after gutted until i changed them.

 

[HakunaMatata]

There is a "Clear Flooded Engine" mode in all fuel injection computers
It shuts off computer injector pulses to Clear a Flooded Engine, lol
Key on engine off
Press gas pedal down to the floor, all the way, hold it down
(Computer sees 0 RPMs and WOT(wide open throttle) so it enters Clear Flooded Engine mode)
Crank engine
It should NOT start, it should not fire, no fuel, this would "dry out" a flooded engine
If it starts then you may have a leaking injector, but would get Rich code on that Bank of engine


If it started.........it may be because throttle cable is stretched, so computer didn't "see" WOT
Use a stick against the seat to push gas pedal down all the way
Go to the engine and see if you can manually open the throttle more
If so
Google: Ranger Throttle Cable Mod
Simple fix
Then redo the test
[/QUOTE]

The engine didn't start doing this test. Just cranked, no sputtering or trying to start.

 

[dvdswan]

I know it's a completely different vehicle but when my 96 Nissan mileage dropped in half I found a bad evap canister. But as @RonD said, I did have a code.

 

[RonD]

Unplug a sensor, like ECT or Throttle sensor or cam sensor, but just one sensor
Start engine
CEL should come on after start up and code should be set
Sanity test for computer

Even if computer is the culprit the gasoline has to be going somewhere
Check spark plug tips

If gas is going thru the engine then at 10MPG spark plug tips will be dark and smoke out the tail pipe

Long shot.................
Dragging brakes
Does vehicle roll easily in neutral?

 

[19Walt93]

What you're calling secondary O2's are actually the Cat monitors and they should be generating codes if the cats fail or are gutted, it means they're working. I know there are defeat devices sold to trick the pcm if cats are gutted but I don't have any experience with them. If the exhaust smells of gas it's running rich. We had a used car dealer bring in an F150 after they had replaced O2's 5 times chasing a lean code while it was running rich. We fixed it by cleaning the O2 ground. You can check all your grounds and connections without buying more parts.

 

[HakunaMatata]

Unplug a sensor, like ECT or Throttle sensor or cam sensor, but just one sensor
Start engine
CEL should come on after start up and code should be set
Sanity test for computer

Even if computer is the culprit the gasoline has to be going somewhere
Check spark plug tips

If gas is going thru the engine then at 10MPG spark plug tips will be dark and smoke out the tail pipe

Long shot.................
Dragging brakes
Does vehicle roll easily in neutral?

Just redid all brakes front and back 3 months ago, rotors, pads, and wheel bearings in the front. Yes it roles very easy. I will pull out a plug tonight and take a pic to post. Funny, I did that exact thing after the wot test before you mentioned it. Unhooked the egr pressure differential switch connector, and by doing that it did throw codes for egr and bank 1 02. It also broke the plastic nipple that goes into the exhaust line. I drove straight to parts store and replaced it. My obd2 scanner for some reason isn't easing codes so I still have them, I'll have to disconnect battery tonight.

 

[HakunaMatata]

What you're calling secondary O2's are actually the Cat monitors and they should be generating codes if the cats fail or are gutted, it means they're working. I know there are defeat devices sold to trick the pcm if cats are gutted but I don't have any experience with them. If the exhaust smells of gas it's running rich. We had a used car dealer bring in an F150 after they had replaced O2's 5 times chasing a lean code while it was running rich. We fixed it by cleaning the O2 ground. You can check all your grounds and connections without buying more parts.

Yes I know what they do, and they have 0 effect on motor or fuel, they only test the cats. I used 2 spark plug anti foulers put together then put into cats with 02 in the end. Easiest and cheapest way to fool the computer.

 

[HakunaMatata]

Welcome to TRS

Yes, around 2007 Ford dropped the Temp Sender(for dash temp gauge) on the 4.0l's thermostat housing, just has the ECT sensor, so just needs the one hole
You can get a new ECT sensor and use the old one to plug the hole in the new housing

The dash temp gauge is now run by computer using ECT sensor data, just FYI

Missing Damper would be a stretch to cause big drop in MPG, its only there to lessen pulse waves in fuel rail
Vacuum hose was there to prevent fires in case Damper leaked, wasn't part of Damper function

You can't have 10MPG and not have Rich codes
So either 10MPG is a user or odometer issue, lol
OR you are leaking fuel out of tank or fuel line
(neighbour kid with siphon hose )
Or Computer has lost its mind

Pull a spark plug, if it is not dark brown or black then you are not running Rich
So neighbour kid or a leak
If it is then its running Rich and computer is the issue

There is a "Clear Flooded Engine" mode in all fuel injection computers
It shuts off computer injector pulses to Clear a Flooded Engine, lol
Key on engine off
Press gas pedal down to the floor, all the way, hold it down
(Computer sees 0 RPMs and WOT(wide open throttle) so it enters Clear Flooded Engine mode)
Crank engine
It should NOT start, it should not fire, no fuel, this would "dry out" a flooded engine
If it starts then you may have a leaking injector, but would get Rich code on that Bank of engine


If it started.........it may be because throttle cable is stretched, so computer didn't "see" WOT
Use a stick against the seat to push gas pedal down all the way
Go to the engine and see if you can manually open the throttle more
If so
Google: Ranger Throttle Cable Mod
Simple fix
Then redo the test

Just thinking here. I have never had to replace the fuel pump. I haven't even tested the fuel pressure, will do tonight. If the fpr is bad in my pump and was pumping to high of a pressure or pumping to much fuel it would return to the tank correct? If so wouldn't the constant fuel movement cause more fuel to evaporate? Could it be an issue with the evap system?

 

[superj]

it would move more fuel and return it to the tank but i don't know if it would evaporate more. i would think it would cause a rich issue and your spark plugs would be showing it

 

[RonD]

The rear O2s will effect MPG but not much

And Lean and Rich codes don't mean what we think of as Lean and Rich
Lean and Rich codes are directly related to Fuel Injector Open Time

Computer is programmed with engine size, and injector size(pounds per hour)
At any given RPM of a 4 LITER engine, the computer will known exactly how much air is being pulled in, it is literally "just math"
And the air to fuel ratio for gasoline is 14.7 to 1, which is a WEIGHT ratio
14.7 pounds of air to 1 pound of gasoline

Computer calculates injector open time for RPMs(air being sucked in)
And that's Fuel Trim 0 for the moment, say is 100ms(milliseconds)
It then looks at Upstream O2 sensor feedback
If Oxygen level is high(lean) then computer adjusts Open Time to 105ms, adds more fuel, this would be Fuel Trim "+5%"
If Oxygen is low(rich) then computer changes open time to 95ms, adds less fuel, this would be Fuel Trim "-5%"

If computer gets to +20% it would set a Lean Code, because its adding 20% more fuel than it should need to, so something is not right
If computer gets to -20% it would set a Rich Code, because its adding 20% less fuel that it should, so something is not right


But NONE OF THIS MATTERS......................lol
At 10MPG the tail pipe should be smoking or the fuel is leaking out



And Computer needs to keep Cats working, so it adds extra fuel now and then to keep the Cats Hot, Cats use/burn gasoline to burn up pollutants
If rear O2s are not showing low oxygen the computer adds extra fuel to try and get Cats working
That won't happen with No Cats, lol, but computer still adds the extra fuel "in hope" that it works
But maybe at a stretch 1MPG, but more like 1/2 MPH drop

 

[HakunaMatata]

The rear O2s will effect MPG but not much

And Lean and Rich codes don't mean what we think of as Lean and Rich
Lean and Rich codes are directly related to Fuel Injector Open Time

Computer is programmed with engine size, and injector size(pounds per hour)
At any given RPM of a 4 LITER engine, the computer will known exactly how much air is being pulled in, it is literally "just math"
And the air to fuel ratio for gasoline is 14.7 to 1, which is a WEIGHT ratio
14.7 pounds of air to 1 pound of gasoline

Computer calculates injector open time for RPMs(air being sucked in)
And that's Fuel Trim 0 for the moment, say is 100ms(milliseconds)
It then looks at Upstream O2 sensor feedback
If Oxygen level is high(lean) then computer adjusts Open Time to 105ms, adds more fuel, this would be Fuel Trim "+5%"
If Oxygen is low(rich) then computer changes open time to 95ms, adds less fuel, this would be Fuel Trim "-5%"

If computer gets to +20% it would set a Lean Code, because its adding 20% more fuel than it should need to, so something is not right
If computer gets to -20% it would set a Rich Code, because its adding 20% less fuel that it should, so something is not right


But NONE OF THIS MATTERS......................lol
At 10MPG the tail pipe should be smoking or the fuel is leaking out



And Computer needs to keep Cats working, so it adds extra fuel now and then to keep the Cats Hot, Cats use/burn gasoline to burn up pollutants
If rear O2s are not showing low oxygen the computer adds extra fuel to try and get Cats working
That won't happen with No Cats, lol, but computer still adds the extra fuel "in hope" that it works
But maybe at a stretch 1MPG, but more like 1/2 MPH drop

Well if it indeed doesnt throw a code until +-20%, then it could be running +15% all the time and not throw a code? That could explain extra fuel consumption. But not enough. Running rich has been an issue for many years. It took the cats out 2 times each side, 1 year apart. But i never get a rich or lean code even before the cats. So replacing the cats will help with mpg, but dont want to replace until i figure out why its so rich in the first place.