At Wits end-So Frustrated/Desperate For Help Clearing Check Engine Light-HELP

[brettallen59]

I m SO desperate! I will send someone $50 if you can tell me what fixes my 1998 Ranger 3.0 with a P0171 & P0174 Codes. I have replaced
O2 bank 2 Sensor 2
MAF
Fuel Filter
Air filter
Plugs
Intake Manifold Gasket
Large Vacuum Lines
Checked for vacuum leaks
PVC valve

Now it is real hard to start in the morning. It fires, but then dies right away. After about 7 tries, I can finally get it to stay running, but it backfires a little and I have to pump it to get it to run. It is a real bitch to get it running.
PLEASE, can someone help me! Should I do a smoke test? Replace fuel pump? What about Idle air control motor or Throttle position sensor?

I have been trying stuff for two months and doing what everyone has been telling me to do but I have run out of options. PLEASE HELP ME. Thanks!
Brett.......

 

[straycat]

If I remember correctly, codes P0171 & P0174 are lean conditions on Bank 1 & 2. It most likely is a vacuum leak (hose or fitting) or a manifold leak issue.

 

[RonD]

Yes, it is Lean condition on both banks of V engine.

These codes come up when computer has added it's preset limit of fuel to a Bank and O2 sensor still shows too much oxygen on that Bank.
These are SENSOR "1" O2 sensors, sensor "2" is located after the Cat Converter so couldn't set 171 or 174, only the O2s nearest the exhaust manifold can, and those are SENSOR 1's.
Bank 1, sensor 1
Bank 2. sensor 1
Bank 1, sensor 2 << after Cat converter
Bank 2, sensor 2 << only on Dual exhaust system and also after the Cat converter

O2 Sensor 2 issue will set a code saying Cat Converter is not working as it should


Since you have chased the Vacuum issue without success, then I would test the other side of the equation, the Fuel Pressure.
1998 Ranger 3.0l will have a "returnless" fuel system, so should have 65psi of pressure at the fuel rail when running.
There is a schrader valve(looks like a tire's air valve), located on the fuel rail, that is where to screw on a fuel pressure tester.
Borrow or rent a fuel pressure tester, test pressure before starting engine, then test it after starting, also test it at 2,500rpm for at least 30 seconds.
Then shut off engine and let it sit for a couple of minutes and see what the pressure has dropped to, and if it is still dropping.

Pressure regulator on the "returnless" system is a check valve in the fuel pump, a back flow preventer.
If the check valve is leaking then fuel pressure would be low, computer expects 65psi of pressure, the amount of fuel injected will be less if pressure is 30psi, so Lean condition.


Hard to start could be fuel pressure, but could be ECT sensor.
ECT(engine coolant temp) sensor is a 2 wire sensor ONLY used by the computer.
There is a 1 wire temp sender used by the dash board temp gauge.
The ECT sensor "tells" the computer the coolant temp, when engine is cold computer runs it rich and sets a high idle, 1,000rpms(choke mode), as engine warms up idle will start to drop and fuel mix is leaned out.

If ECT sensor is "telling" computer the engine temp is 200degF all the time then computer will think it is restarting an already warmed up engine, so a cold engine would be very hard to start since it needs extra fuel(rich mix).

When you finally start the cold engine is the idle at 1,000rpm?
If not then ECT sensor could be at fault.
If it does idle high when cold and then around 750rpm when warm ECT sensor is OK.

A code reader can read the ECT sensors temp, what it is "telling" the computer, if possible read this temp cold and then after engine warms up.

Computer does have a sanity check for most sensors, so will set a code if ECT sensor is acting up, i.e. not changing at all, but if ECT sensor reports 190degF when engine is cold and then 210degF after warm up computer would think it is OK, when it isn't.

 

[brettallen59]

Man, you are awesome! Thank you. I was told since it was both banks, then it would be bank 2 sensor 2. But everything you said made sense. I tried to get the fuel pressure checked yesterday, but there were no mechanics on duty where I went. I might have a pressure checker at home. I will check. Thank you very much man. I appreciate your help. I will try some things and get back to you. Don't know when I will be able to check it though, cause now since the work week started, I'll be working. I'll check in...
Brett......

 

[brettallen59]

I need to do some checking on how to remove the fuel pump. I heard from somewhere that you have to remove the bed to get to the pump. Is that true?
B....

 

[bigmark303]

have you or anyone touched anything to do with the timing on your engine? Camshaft position sensor or anything else? Backfiring is very commonly a timing issue.

Is it backfiring out the tailpipe or through the intake?

 

[black_demon69]

I need to do some checking on how to remove the fuel pump. I heard from somewhere that you have to remove the bed to get to the pump. Is that true?
B....

it is either remove bed or lower tank your choice but removing bed is easier.

i usually just tilt bed back like a dump truck and block it up but when you don't have a helper to remove the bed you improvise.. it takes me about 45 to 60 min to change fuel pump.

 

[brettallen59]

have you or anyone touched anything to do with the timing on your engine? Camshaft position sensor or anything else? Backfiring is very commonly a timing issue.

Is it backfiring out the tailpipe or through the intake?

The backfiring is very minor - just barely a "Poof" when I'm pumping it trying to start it. I really am leaning towards the fuel pump. Gonna get a pressure gage and check it.
B....

 

[RonD]

The backfiring is very minor - just barely a "Poof" when I'm pumping it trying to start it. I really am leaning towards the fuel pump. Gonna get a pressure gage and check it.
B....

Just FYI, on fuel injected engines there are no "jets" or an accelerator pump, like a carb had.
So pumping the gas pedal doesn't really do anything, fuel wise.

But.......if engine is cranking(starter motor turning it) and you press your gas pedal to the floor, the fuel injectors stop working, so you basically cut off the fuel.
This is a routine on all fuel injected engines, "clear flooded engine" routine.
Key on
Gas pedal to the floor<<turns off fuel injectors, to clear flooded engine
Crank engine

What I would do is to get some gas or starting fluid(ether in a spray can)
Pull off the Brake power booster hose and spray starting fluid into the intake or pour some gas in.
Replace hose.

Don't touch the gas pedal, lol.
Try to start engine
If it fires up then dies, you have a fuel issue


You need to remove the gas filler tube(s) from the side of the bed/gas tank and disconnect the tail lights
The 6 or 8 bolts that hold the bed to the frame can be rusty, so it is often a good idea to start there, and if they are too rusted then drop the tank

 

[WNGLDR]

I just changed a fuel pump and a friends 3.0 Ranger. The rear tank strap wouldn't clear the drive line and the bolts connecting the drive shaft to the 3rd member were put on by a gorilla suffering roid rage or something. That said, I will remove the bed from now on when replacing the fuel filter on any Ranger.

 

[brettallen59]

Thank u everyone for your input. My inspection sticker expired in May and you have to have your check engine light cleared in Texas in order to get your vehicle inspected. I have been trying, albeit not very hard, since April.
I don't have an help with my bed removal, but I have an engine hoist, so I can maneuver the bed away just enough to access the pump. I hope to get it done this coming weekend and I will reply with the results. Thanks again! RonD, when I reply I will most likely be asking you for your address in order to send the $50 since I promised to send $50 to the person that tells me what to replace that will fix my problem.