I have had my 2010 ford ranger for a few days now. I picked it up used from dealer. It has a 30 day warranty so i am trying to figure out the bugs now. I am going back in tomorrow to have the door adjusted because it is off the hinge and comes open when you go over a bump. They know about this and are sending it to a body shop for repair. But i am also having trouble starting it. Not all the time but like every second or third time i will have to give a couple attempts. I have a feeling the fuel filter is plugged or the plugs are bad. I am going to buy some autolite plugs and a filter from the actual ford dealership tomorrow on the way to this used car garage so they can put them in. To save arguing. I would rather spend the few bucks. I just want the truck to work. Is there anything else i can check? Does ford charge a lot to reset the computer programming because I Also have a feeling someone messed with the computer with one of those programmers because it is terrible on fuel but has absolute mounds of power. But don't let this rule out the gas filter or plugs because there is a good hesitation when i press the peddle down to when it takes off. But this truck will set you back in the seat. I checked for gas leaks and there is none. When i say bad gas milage. It took a quarter of a tank for a half hour on the highway. It was full right up into the neck of the fill pipe. Does this sound right to you? It is the 4.0 V6... please help

 

the oxygen sensors are made by bosch and only have a 60,000 km life span

if you connect a scanner and read the oxygen sensor data , they will see that the oxygen sensors are no longer transmitting any data to the computer

the engine computer has defaulted to a pre-programmed fuel trim

i replaced my with NTK oxygen sensors and my fuel economy went way up .

22500 up stream 22534 down stream

 

Fuel filter is always good to change when you get a used vehicle, but that won't cause your symptoms.

MPG is not that great with pickups and the 4.0l SOHC engine didn't "sip" fuel so double whammy.

Gauge readings don't help with MPG, reason being is some drop fairly fast above 1/2 tank and slowly drop below 1/2 tank, has to do with the OHMs sender in the tank and gauge.
Assuming speedometer is correct, no oversized tires, so odometer is correct, then set trip odometer to 0 at next fill up and get actual MPG from what it takes to refill next time.
Gallons used for miles driven.

2010 4.0l, 4WD with automatic was rated at 15mpg combined
With manual trans it was 17 combined

Around town only driving would be 14/15mpg, so we are not talking economic vehicle.


Have them(Ford) test the fuel pressure, fuel pressure should hold for a few months when engine sits, if it is leaking pressure when it sits then it will be harder to start.
Try turning key on and off 3 times before trying to start engine, this turns on fuel pump 3 times to rebuild any lost pressure.
If this helps then you are probably looking at a pressure leak, and if you don't smell gas then it would be the check valve in the fuel pump.
This wouldn't effect driving, just starting, because after engine starts fuel pump is on all the time.


When you pull out the spark plugs look at the tips, dark brown or blackish means engine is running Rich, so lower MPG, this could be an O2 sensor issue, false lean.
If spark plugs look good, light brown or white, then O2s are good and engine isn't burning more fuel than needed.

 

so over the last week, i have changed the fuel filter. It was plugged and i have checked the spark plugs. They look clean. I have since driven out all the gas from the tank and refilled with supreme grade and a bottle of injector cleaner. I have used the truck a hand full of times since the supreme gas was added and i have a feeling it was caused by bad gas. I have noticed the gas milage has improved and the starting issue is getting better and better every time. The truck was sitting at the dealership since early july and i bought it last week. It sat with gas in the tank so this could have been the problem. The next time i go for a trip up country i am going to do what RonD said. I will fill the tank to the top then reset the trip counter and when i am to the destination i will top the tank back up, keep note of what it took to fill it back up and see what i got for mileage. The jumpy accelerator issue has resolved its self as well. This might have all been because of the sitting around on the lot for a number of months,

Thanks for the tips.

 

Yes could have been water in the gas(bad gas).

Gasoline and water can't chemically combine together, they separate, and the water is heavier than the gasoline, so the water will settle at the bottom of the gas tank..........where the fuel pickup is.
It takes a few weeks of sitting for the water to settle out.
When engine is started after this it will run poorly with the higher concentration of water but it should clear out after 10 minutes or so.

When you drive around the sloshing in the tank keeps it from settling out and the water that is in ALL gasoline will just be burned without noticeable effect.
Bad gas has a high concentration of water, so will take awhile to clear out of the tank.

Methanol/ethanol can combine with water, it is used in products like HEET, you add HEET to gas tank for one reason but it solves two problems, first it combines with any water in the tank, and makes the water "burnable" but with lower power, once the water combines with the ethanol it's freezing point drops very low, so fuel line freezing at 32degF can't happen, thats where the HEET name comes in and why it is sold more in the North.

If you think you picked up some bad gas then running a 10% ethanol mix or even 15% would be better than 0% ethanol high octane fuel, this would just dilute the water more, which is OK, but the ethanol will combine with the water to get it out of the tank with less notice.

Injector cleaner probably has more to do with the past issues than higher octane fuel.
Injector tips can get residue build up if engine sits for long periods, so they do not Spray the fuel they drip it, especially at lower output/RPM.
Injector cleaner cleans the tip's holes out, so spray pattern is better.

I do it once a year, the can of injector cleaner in the tank, and do notice a difference after using it.