Another rough idle, and hesitation thread... I've done my research, and i'm stuck.
Hey y'all. I'm new to this forum, but not new to jeeps... I just purchased my 3rd jeep and I'm having a strange issue with it lately. I've spent hours researching forums on what it may be... but this one has me stuck, and i don't want to just throw parts at it trying to fix it...
Here is what is going on..
2003 Jeep Wrangler, 4.0L. Lately i've had a rough idle and the jeep will stumble if you bump the throttle, sometimes it won't recover and just die... It runs just fine through all other RPM ranges. The idle seems a bit low to me, between 450-500 rpm when hot. I don't have a check engine light, or any codes stored in the ECM.
Here is what i have checked so far.
-My cats are new, so we can pretty much rule those out as being a issue.
-the plugs have about 1000 miles on them.. they were put on in by the shop when they dropped a new motor in. They are champion RC12ECC plugs, properly gapped, which are what the emissions sticker recommended, but I've read that these newer ignition systems like the double platinum spark plugs so could the plugs i have now be causing this issue?
-All 4 oxygen sensors are fairly new
-I tested my TPS and it sits about .7 volts, and 3.7 volts at WOT.. Now here is where i am stuck. I've read so many places that your WOT voltage shouldn't be over 4.8 volts, or something to that effect... what i don't know is what is a acceptable minimum voltage for WOT? 3.7 volts seems low to me? Ive checked the sweep of the TPS and it seems pretty linear... no erratic voltages, or drops or anything...
-I've cleaned my IAC valve and throttle body, which didn't help any...
Any ideas? other then the rough idle, and stumbling issue the jeep runs fantastic. Thanks for all of your help.