Hi,

I have looked at the forum and can’t seem to figure this problem out because what have worked for others doesn’t seem to work for this truck..

I will start from the beginning and I will apologize for it being a long introduction to this problem. We purchased this truck for our son to park at work and school the truck had sat for at least 2 years with the previous owner, The truck is a 1997 ranger Xtl long bed 4.0. We purchase it knowing it needed brake lines which I have done and fixed that issue. Run the truck for a couple of days and it ran fine. My son takes it to work and calls to tell me on the way home it’s running very rough should he get it towed or drive home being only a half a mile I told him to come home.

Run it on the computer get the only code P0174. Check out the truck visual and see that the purge valve and hose assembly has blown off because the hoses rotted away. Replaced all the hoses and put a new purge valve on the truck because the purge valve had been rotted also. Smoke test the truck from the filler tube and find that the tank is leaking. I pull the bed off and find the filler tube is also dry rotted and replace that as well as a new fuel pump hold down ring. Re- smoke test that and all is fine. Put the bed back on clear the code start the truck runs very rough. Code comes back. Check the air filter and mass airflow both needed replacing as well. While I was at it I replaced the fuel filter and the O2 Sensors because they had never been changed. Clear the code and it comes back.

The engine and all lines have been smoke tested for leaks and None have been found. I took a look at the spark plugs to check for any issues for the plugs and replaced them as well I will post pics of the spark plugs. The drivers side plugs do all the same color while the passenger side had a different color to them also 1 plug on the passenger side was broken.

The egr valve was tested and works as it should. The pcv was replaced 4 dollar part and I also replaced the dpfe sensor and new hoses. While I was at it I also replaced the IAC.

The fuel pump seems to be on the low side according to the online forums its at 30 psi at idle and will go to 40 at about 2k rpm. It does hold the pressure when it shuts off.

This is at idle

This is around 2k rpm

02 sensor not present

Left plug all look the same drivers side and the right plug all looks the same on the passenger side.

This was on the passenger side

All look the same on the driver’s side

The fuel trim seems to correspond to the p0174 code. They also do not change if you rev the engine. The temp is low because I went back to take a picture because I forgot and the car had cooled off.
When the you pull the plug on the IAC the engine will go from 1000 to 500 rpm or stall entirely.
I would lean to a leak somewhere but everything was smoke tested and no leaks found. At this point I might just switch out the fuel pump and if that doesn’t work try the pressure regulator.
Checked the o2 sensor wiring and they have power. I checked because the o2 sensor showing not present. The truck was also checked for broken grounds.
I know it was a long read but does anyone have any other thing’s they would look at ?
Thanks

 

whats the mileage?

 

141k. And just switched the fuel pump still didn’t work

 

there should be voltage data from the O2sensors? if they havent been changed they need to be. they do go bad at 100k mi or 10yrs. the IAC sounds good thats what it should do when unpluged. so what exactly is the problem?

 

I just replaced the fuel pressure regulator and that still didn’t change the pressure still holding at 30psi feel like it was a waste of money at this point for the fuel and pressure regulator. I did change the 02 sensor upstream on drivers side but not upstream on passenger or downstream. A lot of these items I changed because of the age of the truck and seeing I’m doing the work it’s only for the parts. I at my limit with this. I’ll change the other 2 02 sensor and maybe if that doesn’t work I’ll go for the injectors. It’s funny the truck ran great till the 1 line blew off because of the age. Keep the ideas coming I’ll try anything at this point because I know we have no air leaks.
thanks

 

The truck runs rough and shakes badly when you try to drive it and the codes for p0174 keep coming back. You cannot drive it seems like it doesn’t want to go almost starving for fuel that’s why I figured changing the fuel and regulator.

 

it its just bank 2 its an issue with just that bank. also you should replace bank 1 upstream O2 sensor. should be easier on that side? i would then check with your reader again. you'll need to get the motor up to temp. for a good reading. Long Term is what you are looking for. O2 sensors dont start working or send info untill they are heated to 600dg. downstream sensor has nothing to do with the motor, it just lets you know it the cat is ok. it has to do with something fuel or air on only bank 2.. bank 1 might be screwing things up. O2 sensors just lets the ECU whats going on.

• Bad Fuel Injectors:
  Faulty fuel injectors can deliver the wrong amount of fuel, leading to a lean condition.

• Other Issues:
  A malfunctioning O2 sensor,
• IF THESE WERE BAD IT WOULD SEND A LEAN CODE FOR BOTH SIDES. a bad EGR valve, or a faulty coolant temperature sensor can also contribute to a lean condition.

 

Thanks for the reply. I will change out the coolant sensor and the other 02 side 1 sensor tomorrow and report back. If that does not work I will go after the injectors next.
thanks

 

i dout if its the coolent sensor if it was the code would be for both sides Bank 1 and 2 . its odd that all bank 2 injectors would be bad at the same time. i believe there are 2 tem things. one is a sender the other is a sensor. one for the gauge other for the ECU. they are both different.

and what is Bank 1.2.3.4? you only have Bank 1 and 2. the O2 sensor might do it, fingers crossed

 

I changed the temp sensor and the O2 sensor. The truck ran good for the first 10 minutes till it warmed up once the truck was warm. It went back into shaking mode where you couldn’t drive it and it was bucking pretty bad at this point. I’m at a total loss. The only thing that I can think of is maybe there is a small a leak somewhere around the oxygen sensor that I’m not picking up with the smoke test. I’m gonna try shaking the pipes to see if it works when it’s shaking versus just standing still. Yes.

 

ok what temp sender did you change? for the gauage or ECU? The senders (for the Gauge) are generally conical, while the sensors are cylindrical. (not always though).how do you know the motor got to temp? if the motor got to temp 195deg thats when Long Term takes over. any new codes? heres a copy of my engine #s its a 3.0 but should give you something to go by.

 

 

note voltage on B1 sensor 1 and B2 sensor 1. both .02v

 

I changed the 2 wire sensor not the single wire sensor. Truck ran good in open loop and when it went to closed loop went back to rough idle.

 

Forgot to add no new codes came up just the same code as usually. I’m going to try to un plug the o2 sensor and see if it generates a code. My computer does not pick up the o2 sensor and it also shows no volts to the sensor. I un plugged the sensor before and did get power to it but did not test for voltage just used a light tester for power. Will try to see voltage at the sensor. I’m starting to think maybe I need a newer diagnostic computer any suggestions? I have been using scan xl pro. I understand it is older but it has worked for me up till this point but maybe something newer might be better.

 

I think it's time to pop open the ECM and check the capacitors.

 

What was the temperature? Can you tell if the O2 sensor is working on bank 2? Was there any voltage to it? Can you tell?

 

An ELM OBD Bluetooth or Wi-Fi sender and there is plenty of free apps that can give you live data. I got my reader off eBay for under $20 and I use the app that cost five dollars

 

Can’t tell if the 02 sensors are working because my computer does not show voltage on any of the 3. At this point just for the try it’s a cheap part maybe a faulty iat sensor. It runs and idles cold not when it’s warm I know I’m grasping but it’s got me perplexed. I appreciate all the help because this has me stumped.

 

I guess one way to check would be take the sensor out of bank 1 and put it in bank 2. Take the one out of bank 2. and put it in bank 1. if nothing changes that means to me the sensor is trying to work there’s a problem, possibly with the ECU. The only thing that knows that goes from short term to long-term are the O2 sensors and the ECU. The other question is which temperature sender or sensor did you change? I’m not sure if there’s two on that motor?

 

Just checked the voltage on the sensor wires and that’s correct. Smoke the truck again still no leaks. Even went to spray carb cleaner all around to see if leaks and no change in idle. So at least the smoke test was correct. Sensor that changed was temp sensor 2 wires not the temp sensor for the dash. Just getting frustrated at this point.

 

Just checked every area I could with carb cleaner to see if idle changes or values change and nothing happens so it’s not an air leak at least I can find. Maybe try some different sensors

 

ok heres what you need to prove is working. motor will go up to temp 190dg or close. both upstream O2 sensors are working. there is a voltage reading or some sign that when they are producing info to the ECU. the next thing would be pull the ECU and open it up and look at the capacitors, they do go bad.

 

Looked at the ecm and it looks good. I changed the egr solenoid because it was bad. Also picked up new wires figured I changed the plugs should have changed the wires and now it runs worse. I going to order a new ecm the 3 o2 sensors still do not pick up and it now said fault for the o2 sensors. Wires all get power. Will keep at it. It just sucks because I have to order the parts no one around me has it in stock order in am get it in pm try and repeat.

 

Problem seems to be fixed. Put a new 02 sensor downstream. Seemed to be the wrong one that was used and it snapped off trying to get it out. Cleared the codes and all runs good no more codes. Maybe the downstream was shorting out the upstream who knows. Could have been a combination on everything that I switched.