Running rich on both banks and can not figure out a reason why. New injectors new fuel pump new maf sensor no vacuum leaks new plugs wires coil pack on bank 1 Ltft is about -25% bank 2 is about -10%

 

Welcome to the forum

What YEAR Ranger?
What engine size?

And what were the exact codes, code list here for 1995 and up Rangers: https://www.therangerstation.com/tec...II_codes.shtml

 

sorry it is a 99 3.0
P0172
P0175
and now a misfire on 6 P0306

 

Any sign of an issue with the OLD spark plugs
Were the tips OK or blackish?
On ANY

The 1999(1998 and up) runs 55psi fuel pressure so I doubt its a fuel pressure issue, i.e. to high
Its possible, there is an FPR(fuel pressure regulator) inside the gas tank with the fuel pump
But long shot

Lean and Rich codes do not mean the engine is running Lean or Rich, just FYI
These codes mean the computer's Calculated amount of fuel to add to the air it "sees" is off

The computer calculates each fuel injectors OPEN time based on air flow(RPM and throttle position)
And fuel pressure of 55psi
This calculated value is 0 STFT(short tern fuel trim)
Say that calculated OPEN time is 100ms(milliseconds)
So it opens injectors for 100ms
It then looks at O2 sensor voltage, .1v to .9v, .1 is lean, .9v is rich
If its .1v then computer changes open time to 102ms(adds more fuel), +2 STFT, +2%, then 104ms, +4 STFT, 4%, ect.......until O2 shows .4v
Same for the other way
If its .9v then computer changes to 98ms(adds less fuel), so -2 STFT, 2% less OPEN time, then 96ms open time -4 STFT, ect .......until O2 shows .4v

This all takes maybe 2 seconds, it happens very very fast, so engine is never running Lean or Rich

If STFT gets to -20 to +20 computer will set a code, Rich or Lean, to tell the driver that its calculations are off by more than 20% which is alot, lol

If your exhaust is blowing out grey smoke then engine is actually running Rich
Or if engine is pinging then its actually running Lean


Any way, if possible I would check fuel pressure, just to take it off the table

Also if any OLD spark plug was black then that injector could be leaking which throws off the whole system

 

yeah i can check fuel pressure. checked the plugs and they all looked good. i even swapped plugs and wires from 2 and 6 on the coil pack to see if the coil pack or wires were bad. when i bought the fuel pump it was the whole assembly. i changed out all 3 o2 sensors today.

 

Unhook battery when doing any changing of engine parts
This does two things, safety of course, but it also can reset "learned" memory in computer, not always but usually

If you have a vacuum gauge test for clogged exhaust too

 

so when running its reads right around 58 to 59 psi but with just the key on it goes from right around 55 and slowly drops.

 

havent tested for clogged exhaust. like reading for a bad cat?

 

and unhooked the battery everytime after changing a part plus it has a new computer in it

 

Fuel pressure numbers are OK.

Was the problem of Rich codes why you got new computer?


i.e. a 1997(or earlier) 3.0l computer would want 35psi fuel pressure, and would set rich codes in a 1999 ranger

Also a 1999 3.0l gas only computer would set Rich codes running 3.0l Flex Fuel fuel injectors, they were larger injectors so let in more fuel than the gas only injectors

 

well everything was leading towards a new computer they did a bunch of welding on the truck(previous owners) so i figured they screwed the computer up. i was getting rich and misfire on 6 codes prior to getting the new computer installed. the heads were checked and they tested good. i have yet to check ohms on the new injectors. was gonna pull the manifold off and check voltage and ohms on all injectors.

 

and from the vin on the truck i determined it was a flex fuel motor is there anywhere else on the motor or anything to determine it being not flex fuel. its got 180XXX miles on it. while driving it drives good just it stumbles when taking on and shakes a bit from the misfire

 

No, there are no numbers on a 3.0l engine that denotes gas only or flex fuel, the head's chambers are different but interchangeable, only real difference is the flow size of the fuel injectors used.
I think the VIN "U", gas only 3.0l, used 19lbs injectors and the VIN "V" used 24lbs

So the 8th digit of your VIN is V

And the computer you got was for a V..........a flex fuel computer, or did you just go by the numbers on old computer?

If you do pull out an injector get the part number off it to see what size it is

Using a gas only computer with flex fuel injectors would explain the Rich codes

Look here for 3.0l info: https://www.therangerstation.com/tec..._0-build.shtml

The head castings for flex fuel(methanol) do have a different number than gas only but not sure where the number is on the casting

 

yeah i matched the computer with what was in it.. it was running great for like 6 months no issues and then i got a misfire on i believe 4 and then i changed plugs wires and coil pack and then went to 6 so then i figured it was and injector issue..bought gas injectors and it didnt run good at all and thats when i realized it was a flex fuel motor. got new injectors . its wierd runs great for about 10 minutes after installing new parts but then runs like **** after.. right now the misfire on 6 is there but running rich is pending right now.

 

the computer number is XL5F-12A650-YF

 

Well a cold engine needs extra fuel, needs to be "choked", which means to run rich
When it warms up it needs regular 14.7/1, air/fuel mix

So when you unhook the battery(install new parts) it seem to run better for a few minutes?
Have you try unhooking battery after its warmed up and then reconnecting it after say 5 minutes to see if it runs better

 

yes sir should i check the thermostat and the sending unit?

 

One other thing that just occurred to me about VIN V flex fuel 3.0l

1999 probably has an Ethanol sensor, by the fuel filter in the frame rail, it will have a 3 wire connector
Unplug it
Drive it, you should get a new code
Code would tell you computer is indeed using this sensor, and if sensor is failing and telling computer you are running a higher ethanol mix(over 40%) then you would get Rich codes all the time because calculations are based on faulty data, the fuel type

This sensor is silly expensive to replace, $650-$850, if you can even find one
But you can get a "replicator" type sensor for $160, this tells computer you are running gasoline(max 10% ethanol), so you no longer have a flex fuel option, but usually not an issue for most people who run gas only anyway
Seen here: http://www.pointaengineering.com/Fle...NFO-000002.htm

 

So I unplugged it and drove it just got the code for it being unplugged but not any rich or missing codes. Bought the replicator and installed that today and now after driving it...on my code reader it’s just showing a rich bank 1 pending code

 

OK, just have to wait and see I guess

 

yeah drove it some more and both banks are running rich again. It also has this high idle then drops after like 5 seconds when you come to a stop. as well as when shifting gears it jumps high like the TPS is sticking or not releasing.

 

or the injectors are sticking open like the pulse of the injectors

 

Can you see Live Data with your OBD2 reader?

 

yes sir i can what readings would you like to see?

 

LTFT on both banks, should be minus 15-25

And then see if you can Clear them, not sure if you can
If not unhook either battery cable and wait 5min and then hook back up to see if they were cleared

Did you unhook battery when you added the replicator?