Anybody good at diagnosing data logs??

[slvr08gt]

My car is idling horrible, smells like its running really rich, and is slightly surging during normal driving. Wont throw a single code but it idles like I'm on a ghost cam tune.

I've replaced or checked the following:

New plugs gapped at .050
New PCV valve
Cleaned the intake manifold
Moved and swapped around the coil packs
Cleaned the MAF
Reseated the injectors/ checked for bad o-rings
Ran a 1/3 can of seafoam through the intake
Performed a compression test. All were within or under 10% of each other


I know how to data log fairly well, but when it comes to interpreting the data I'm a frickin newb, lol.

So if anyone is good at it, let me know what PID's you need me to log and your email, and I'll shoot you the log. I would also be willing to donate some funds if someone could spot the issue. The only thing left that I think could be causing it to run this way would be the front o2's.

Maybe a tuner on here could spot the issue easily, who knows......another week or so of my car running like this and I will set it on fire.

Reason for not taking it to the stealership is because I flashed it back to stock last week and I know they will see the low clock count in the PCM among other things.

Thanks in advance!

Nick

 

[BruceH]

Did it happen all of a sudden or was there some work done and then it started? The first things that come to mind is a vacuum line or the maf is in backwards. Do you have the correct tune installed?

 

[slvr08gt]

Did it happen all of a sudden or was there some work done and then it started? The first things that come to mind is a vacuum line or the maf is in backwards. Do you have the correct tune installed?

Stock tune is currently loaded. No change in the issue. MAF is facing the correct direction. The rough missing idle gets worse and worse after every day.

Here's my original thread I started when everything started going down hill:

http://www.s197forum.com/forum/showthread.php?t=100245

 

[wbt]

E85? If so, probably a bad o2 sensor

 

[slvr08gt]

E85? If so, probably a bad o2 sensor

No e85 on this shit hole island. Only ran 92 octane in it since the day I bought it new.

Anyway of telling if a o2 sensor is bad without it throwing a CEL?

 

[Sprayer84]

No e85 on this shit hole island. Only ran 92 octane in it since the day I bought it new.

Anyway of telling if a o2 sensor is bad without it throwing a CEL?

Look at the voltage. It should bounce up and down from about .2-.9. If it is steady high or low your tuning Rich or Lean. If it sticks it also may be lazy. Compare one side to the other. Should be about a mirror image.

 

[BruceH]

E85? If so, probably a bad o2 sensor

How do you figure that?

Stock tune is currently loaded. No change in the issue. MAF is facing the correct direction. The rough missing idle gets worse and worse after every day.

Here's my original thread I started when everything started going down hill:

http://www.s197forum.com/forum/showthread.php?t=100245

Read the thread. It all cleared up when you changed plugs but then came back? It no longer smokes, and only one side smelled funky, correct?

How do the plugs look now?

 

[slvr08gt]

Look at the voltage. It should bounce up and down from about .2-.9. If it is steady high or low your tuning Rich or Lean. If it sticks it also may be lazy. Compare one side to the other. Should be about a mirror image.

Hmmmm. The past couple idle logs I've done, I've noticed the lambda voltage readings stay in the .95-1.01 range.

How do you figure that?



Read the thread. It all cleared up when you changed plugs but then came back? It no longer smokes, and only one side smelled funky, correct?

How do the plugs look now?

Correct. When I changed the plugs it took away the horrible misfire I had at WOT but it still idled rough. Day after day the idle continues to get worse. I'm guessing the first set of plugs was only one the issues causing it to do that. Something still isn't right with the idle though.

Plugs look fine. Dark grey and dry.

I just did another 2 minute idle log. If anyone wants to take a look at it, shoot me a PM with your email addy and I'll email the log to you.

 

[Fullboogie]

OP - I don't see where you've addressed a possible vacuum leak.

 

[slvr08gt]

OP - I don't see where you've addressed a possible vacuum leak.

To be honest. I don't even know where to begin for a vacuum leak. The only vacuum source I'm familiar with on these 5.0's are the break booster line and the crankcase lines that run from the valve covers to the intake manifold and air intake.

I've already checked those and don't know where else a vacuum leak could even come from.

 

[Alfiedagr8]

To test for a vacuum leak. Usually fuel trims are at idle are at there worst. As you raise the rpm and open the throttle you will see the trims get closer to zero.

Sounds like a leaking injector to me but then again I'm not there. So do this. Unbolt the rails and raise the rails with the injectors still attached to the the rails and turn the key to the on position and see if any leak


Sent from my iPhone using Tapatalk

 

[slvr08gt]

To test for a vacuum leak. Usually fuel trims are at idle are at there worst. As you raise the rpm and open the throttle you will see the trims get closer to zero.

Sounds like a leaking injector to me but then again I'm not there. So do this. Unbolt the rails and raise the rails with the injectors still attached to the the rails and turn the key to the on position and see if any leak


Sent from my iPhone using Tapatalk

Just pulled the rail with the injectors attached, turned the key to ACC and they didn't leak a drop.

Nick

 

[Seer]

torn coil wire?

 

[slvr08gt]

torn coil wire?

Checked them already. Also tried unplugging each CP individually.

 

[Fullboogie]

To be honest. I don't even know where to begin for a vacuum leak. The only vacuum source I'm familiar with on these 5.0's are the break booster line and the crankcase lines that run from the valve covers to the intake manifold and air intake.

I've already checked those and don't know where else a vacuum leak could even come from.

With engine running, spray brake cleaner or starting fluid around the engine. If the idle changes, you've found your vacuum leak.

 

[WILECYOT]

Does anyone else just use a simple boost leak detector to find vac leaks anymore?

 

[wbt]

How do you figure that?

I and others have had issues with failing o2's running e85. The OP symptoms match. Last track visit I had a driver side o2 crap the bed and it took some time for the CEL to trigger. That is why I asked about running e85.

 

[Godzirra]

Spark plug gap? Mines gapped at like .032 or .036 can't really remember

 

[ochoblanco]

Spark plug gap? Mines gapped at like .032 or .036 can't really remember

Stock Motorcraft plugs are gapped out at .051 or something like that I believe so shouldnt be an issue.

 

[slvr08gt]

With engine running, spray brake cleaner or starting fluid around the engine. If the idle changes, you've found your vacuum leak.

Gave it a try. Couldnt get the idle to increase.

I and others have had issues with failing o2's running e85. The OP symptoms match. Last track visit I had a driver side o2 crap the bed and it took some time for the CEL to trigger. That is why I asked about running e85.

How long did it take for the CEL to pop up? Mine has been acting this way for close to two weeks now.

Stock Motorcraft plugs are gapped out at .051 or something like that I believe so shouldnt be an issue.

Correct.