Why am I running rough at idle and stalling??

[doczenith1]

My engine light came on (and stayed on) early this week while my sister had my truck. I drove it today (engine light still on) and it likes to stall at idle. It also seems like it is 'missing' while accelerating. Last weekend we got some heavy rain and I splashed through many deep puddles. Could something be wet? There is about 72000 miles on the truck and it has the original plugs.

Thanks,
Al

[Snake Eyes]

Bad coil?

[budman451]

Before attempting to just throw parts at it and hoping to fix it, I would find out what code is tripping the SES lamp. That should give you a direction to start in troubleshooting.

Buddy

[doczenith1]

I took my truck to a parts store and they hooked up their scanner to it and these are the results.

Vehicle Scanned
Global OBDII
Vehicle

DTC (Codes)

P0720
Output Speed Sensor
Circuit Malfunction



DTC Pending (Codes)

No Faults Detected


So, I still don't no for sure why it is missing. The guy at the parts store tried to tell me the tranny was not functioning properly causing the truck to stall at idle. I told him it did it in park and he said that the tranny was not releasing the torque converter properly and gave me a business card for his friend who owns a transmission shop. I smile and said thank you, walked out the door and threw the card away when I got home.

From the other related post in this forum it looks like I need to take it to a mechanic that can hook up a more advanced diagnostics tool. Can any mechanic do this or do I need to go to the Ford dealer?

Thanks,
Al

P.S. Good thing I just bought a 2003 Cobra last week. Perfect timing [img]/ubbthreads/images/graemlins/smile.gif[/img]

[jss304]

[ QUOTE ]
I took my truck to a parts store and they hooked up their scanner to it and these are the results.

Vehicle Scanned
Global OBDII
Vehicle

DTC (Codes)

P0720
Output Speed Sensor
Circuit Malfunction

DTC Pending (Codes)

No Faults Detected


So, I still don't no for sure why it is missing. The guy at the parts store tried to tell me the tranny was not functioning properly causing the truck to stall at idle. I told him it did it in park and he said that the tranny was not releasing the torque converter properly and gave me a business card for his friend who owns a transmission shop. I smile and said thank you, walked out the door and threw the card away when I got home.

From the other related post in this forum it looks like I need to take it to a mechanic that can hook up a more advanced diagnostics tool. Can any mechanic do this or do I need to go to the Ford dealer?

Thanks,
Al

P.S. Good thing I just bought a 2003 Cobra last week. Perfect timing [img]/ubbthreads/images/graemlins/smile.gif[/img]

[/ QUOTE ]

I could be wrong here, but every time I've had an issue with the speed sensors, the ABS light would come on, not the SES light. Any good mechanic would probably have a better scan tool; I don't think you need to take it to a dealer.
-Jason

[BASSAGE]

Could be the IAC motor is sticking.....the 90 degree elbow that goes into the back of the intake from the pvc valve could also be leaking.

Just some things to look at.

Good luck.......Dan

[BBBxcursion]

EGR sticking open would be my guess. Get the codes pulled and see what comes up. IAC would not cause the engine to mis while accelerating.

[BASSAGE]

No the IAC won't make it miss, but it will let the engine stall like the first part of the post said........is this not true?

Dan

[doczenith1]

I drove it for the first time in a few days and it is running fine which leads me to believe something got a little wet and is now dry. The SES light is still on and I dropped it off at the dealer this morning. Will post the results when I get them. Thanks for all the input!

Al

[BASSAGE]

Good luck Doc!!

Have a good one....Dan

[doczenith1]

Took the truck in to the dealer and here are the results:

"Scanned vehicle. Found miss on cylinders #2 and 4, found coolant in cylinders then removed coils from 1 and 3, also found coolant in them, cleaned 1 and 3 then replaced coil and plug on cylinder #2 and a plug in #4."

Before I took the truck in I removed my heater core mod (see pics) and some coolant spilled on the engine. I did this the day before I took the truck in. The truck ran fine on the way to the dealer. I did spill some coolant when I installed the mod a few years ago. Perhaps this caused the coil to malfunction over time.

Total cost was $241.00 which included $160 in labor, $58 coil, two $3 spark plugs and tax.

[fordguy09]

You a city boy? lol That was about the most apparent sounding thing in the world, any time you have stalling missing, and worsening on hills, etc. My first thought it check plug wires, plugs, coil. Easiest but most "shocking" is leave vehicle running, and listen to the motor, one by one take off a spark plug wire, if the wire is working well, it should miss bad, and sound like [censored], if it is bad there should be little or no difference, if you ever do this dont be surprised to get a little shock. But if you change the wire, and it doesn't fix the problem, replace your coil pack. Thanks fordguy09

[Snake Eyes]

Hmmm, my first post to this thread read...

"Bad coil?"

[doczenith1]

[ QUOTE ]
You a city boy? lol That was about the most apparent sounding thing in the world, any time you have stalling missing, and worsening on hills, etc. My first thought it check plug wires, plugs, coil. Easiest but most "shocking" is leave vehicle running, and listen to the motor, one by one take off a spark plug wire, if the wire is working well, it should miss bad, and sound like [censored], if it is bad there should be little or no difference, if you ever do this dont be surprised to get a little shock. But if you change the wire, and it doesn't fix the problem, replace your coil pack. Thanks fordguy09

[/ QUOTE ]

Did I grow up living in a city..yes. Am I a "city boy" no. I grew up working on a farm and also working on cars and tractors. Have done all sorts of engine work including an engine swap in my 1978 Ford Fairmont (they were so good they quit making them, nobody was buying new cars) [img]/ubbthreads/images/graemlins/laugh.gif[/img] . I figured it was either a bad coil or spark plug but when I got around to checking which one the engine was running fine. I took it to the dealer because the SES light was still on and I wanted to have them hook up the diagnostics equipment and make sure everything was right. I will be towing the boat a lot this summer and don't want to breakdown on the side of the road.

[ QUOTE ]
one by one take off a spark plug wire

[/ QUOTE ]
You a diesel boy? lol I don't think they have made gas automobile engines with spark plug wires for quite a while. It is all coil-on-plug now.

And yes, I've felt the shock from a spark plug more than once [img]/ubbthreads/images/graemlins/smile.gif[/img]

[Snake Eyes]

That's one nice civil reply there "City Boy"! [img]/ubbthreads/images/graemlins/laugh.gif[/img]