Not smooth (not exactly rough) idle on Jeep GC 2000...

[sontakke]

What software are you planning to use with iPad/iPhone?

I was googling for older scanner systems such as BR-3, Alex Peper etc and I realized that most of these early pioneers are no more. Even the autotap went diy express and no longer have enhanced PID support. It looks like elm, Autel and Centec have taken over all that market.

- Vikas

 

[mvbighead]

Well, just checked, and no misfires. I did historical, as I figured it should let me know if anything has been happening since my last battery disconnect. Perhaps I could do current or whatever, but it didn't seem like anything was listing anywhere.

Also, I was checking O2 sensors with the app, and the voltage reading seemed to be all over the place. Having not used this on my other car, I have no idea if this is normal or not. Any ideas?

 

[mvbighead]

Any other ideas gents?

 

[LTC8K6]

A good O2 sensor will have a nice, fast, regular oscillation from min to max voltage at idle, IIRC.

Have you compared the Jeep's idle to other vehicles?

 

[mvbighead]

A good O2 sensor will have a nice, fast, regular oscillation from min to max voltage at idle, IIRC.

Have you compared the Jeep's idle to other vehicles?

Gonna work on that soon. I'll be checking my wife's vehicle, but she'll be out tonight and I ended up driving the Jeep today.

Also, my brother's wife drives the same Jeep I do (a year newer though), so I can likely find a good test comparison.

Big thing right now is getting a hold of the wife's car to compare the functionality as well as the O2 readings.

 

[sontakke]

Well, just checked, and no misfires. I did historical, as I figured it should let me know if anything has been happening since my last battery disconnect. Perhaps I could do current or whatever, but it didn't seem like anything was listing anywhere.

Also, I was checking O2 sensors with the app, and the voltage reading seemed to be all over the place. Having not used this on my other car, I have no idea if this is normal or not. Any ideas?

Plot the primary O2 sensor voltage. How many primary O2 sensors does it have? It will have nomenclature S1Bn where "n" is the bank number. Ignore the S2Bn for time being. Deselect all other parameters and select the following for graph

S1B1 voltage
S1B2 voltage
LTFT Bank 1
STFT Bank 1
LTFT Bank 2
STFT Bank 2
RPM
MAF

Let it idle for couple minutes and then rev it to 2500 for a minute. If you can get the data logged, we might be able to see any abnormalities.

But don't get your hopes up. If you really want to debug this further, you might have to get your hands lot dirty i.e. lot more tests and/or parts swap.

- Vikas