2004 Explorer 4.0 Running rough intermittently and stalling.

[Matt Stine]

Hi Guys,

I decided to join after visiting this forum several times in the past and found the answers I was looking for but the issue I have now I have came up empty. I'm sure someone here has seen this before or I hope so at least. My 2004 Explorer (Eddie Bauer)with the 4.0 will run smooth like everything is OK for a couple minutes and then it will start chugging almost like its out of fuel. If I pedal the gas it doesn't seem to react very well and sometimes it will clear up and run smooth again other times it does die. I can hold my foot on the pedal at a steady 2000rpm or so and everything is smooth no issues noises etc then it just starts chugging like its out of fuel. I hooked up my scan tool to it and it did have the following codes

P0302: Cylinder 2 Misfire Detected

P0171 & P0174 (Too lean bank 1 & Too lean bank 2)

P0316 Misfire Detected on Startup (First 1000 Revolutions)

I have done the following test to troubleshoot and replaced a few items along the way also.

1. Checked to make sure I had good fuel pressure at rail. It checked 30psi which was on the low side so I replaced the pump with new have good pressure now.

2. Checked spark plugs and wires. Did find that one wire was arcing a little against valve coveer and originally thought this must have been my issue. Replaced plugs and wires with new still same issue.

3. Found a small vacuum leak around EGR valve so replaced with new. No change.

4. Replaced fuel pressure sensor on fuel rail. No change.

5. Replaced intake manifold gaskets. No change.

6. Replaced throttle body. No change

7. Cleaned MAF. No change and yes car does run worse if I unplug it.

8. Replaced harmonic balancer with new from ford. Did this when I did the timing chains but still it has been replaced.

9. Replaced coil with unit from pull and pay. No change.

When I have this hooked up to my scanner all the data looks OK to me. No abnormal voltages, engine RPM is reading steady not fluctuating or indicating a bad crank sensor. I'm stuck and appreciate any input or things to check anyone can offer.

 

[Matt Stine]

Forgot to list that I did a compression check on cylinder #2 and it checked good 138ish. I also check the resistance of the injectors just to be sure they were not open and they all check good also. Thanks again for any help.

 

[Tech By Trade]

Pop the valve covers and check your timing on your cams with the OTC tool.

 

[edcantu9]

Check the simple first stuff first. Check the spark plug on cylinder 2, how old is it? Is it gaped correctly? Then check the COP. You do this with a multi meter, check for resistance of 1.0-1.2.

Look up an application called Forscan. It is free and will give you a lot of information on your car.

Quit replacing stuff until you know for sure what is wrong.

The more you mess with the more chance its something you did.

 

[Matt Stine]

Pop the valve covers and check your timing on your cams with the OTC tool.

That's a good idea I didn't think to check that again. It's been about 3k miles since I did them. I did double check everything was lined up again before I installed them but I will definitely do that tonight. Thanks for the suggestion.

 

[Matt Stine]

Check the simple first stuff first. Check the spark plug on cylinder 2, how old is it? Is it gaped correctly? Then check the COP. You do this with a multi meter, check for resistance of 1.0-1.2.

Look up an application called Forscan. It is free and will give you a lot of information on your car.

Quit replacing stuff until you know for sure what is wrong.

The more you mess with the more chance its something you did.

Thanks for the suggestions. The plugs have about 3k miles on them, and the wires are brand new. Also I have the SOHC 4.0 so it has one coil pack no COP. I have Auto Enginuity scanner with the FORD add on however it is new to me and am still trying to figure it out but at first glance i did not see anything abnormal in the data. I will still check out the Forscan just to see if I may like it better.

 

[edcantu9]

Thanks for the suggestions. The plugs have about 3k miles on them, and the wires are brand new. Also I have the SOHC 4.0 so it has one coil pack no COP. I have Auto Enginuity scanner with the FORD add on however it is new to me and am still trying to figure it out but at first glance i did not see anything abnormal in the data. I will still check out the Forscan just to see if I may like it better.

you are going to regret purchasing the enginuity app after using forscan.

 

[imp]

@Matt Stine Did you check fuel pressure after installing the new pump? If not, suspect fuel filter, if it was not replaced as a possibility. imp

 

[07gtman]

What kind of plugs did you put in? Motorcraft should be the only plug you should be using.

 

[Drewmcg]

How many miles on this thing?

Does your scan tool report normal engine temps w/in normal warmup time (e.g., 10 minutes, depending how cold outside)?

 

[Matt Stine]

Ok I did some of the things suggested over the weekend and still no luck. Timing checks good, Motorcraft plugs are the plugs I am using and the fuel filter was replaced with the pump as recomended. I am starting to wonder if I could have an issue with the FPDM module? Is there a troubleshooting method or procedure on these? These intermittent issues are the worst lol. @Drewmcg it does warm up normal however it doesn't seem to care what the temperature is it messes up warm or cold. I appreciate everyone's time and suggestions!

 

[Matt Stine]

Did some more checking today with my scan tool. Looks like my short term fuel trim is at 35% and it runs ok when its like this however it changes to .1% when it goes into closed loop I believe and then it start spitting / sputtering and eventually stalls. I did notice that my fuel pressure gauge was bouncing around pretty badly when this happened as well. It gave me a P2197 code now. I hate to take this thing to the stealership but thats about where im at with it unless someone has some other suggestions that i could check.

 

[07gtman]

What are the symptoms of the P2197 code?

• Check Engine Light
• Misfires
• Low power output
• Possible overheating
• this is a vacuum leak
• lean condition

 

[07gtman]

try spraying some carb cleaner around the intake manifold,And vacuum hoses while the engine is running, If it starts to stall you found your leak.. be very careful while doing this if you have a bad coil it can start a fire...but also is a good way to find a vacuum leak