So I have about 4200 miles on my LS engine in the Jeep now and it has been running phenomenally. However, during the last several tanks of fuel I have been getting a P0442 code which is a small EVAP system leak, small as in less than .020” so usually the gas cap is the culprit. The gas cap is the original that came on my 2011 Jeep Wrangler so it is logical that it could have lost its seal. Rather than diagnose it because we were in the middle of my son’s LB7 injector project I simply stopped by my local Chrysler/Jeep dealership and bought a new cap. I prefer the OEM caps because they have the provisions for the lanyard whereas the aftermarket ones do not, at least on the majority from my experience. Well, the gas cap was NOT the source of the leak.
Friday night I had a little time after getting home from work so I decided to pull the Jeep into the shop and properly troubleshoot it and correct the problem.
I hooked up my trusty old OTC smoke machine (Leak Tamer) in preparation for diagnosing.
Turned on the smoke and you can see by the flow meter that a leak is present as it is pegged.
I looked everywhere and could not see smoke coming out of any of my connections or the ESIM (Evap System Integrity Monitor) which is kind of another location I was suspecting if it wasn’t my hose connections. There is a quad ring that seals the ESIM to the EVAP canister and I had disturbed it during the pinning of the shuttle valve during the LS swap.
You can pinch off the hose coming out of the vent valve because it is normally open but I prefer to use the computer to simulate the operational sequence so I used my scanner to activate the vent valve thus closing the vent valve.
After not seeing any smoke I decided to pull the hose leaving the closed vent valve and BINGO, there’s the problem. There should not be anything passing through the vent valve.
For reference, this is the vent valve deactivated (open). I hope you can see the difference and it shows up in the pictures.
I went ahead and put a plug/cap on the outlet of the vent valve and the flow meter dropped to zero so I needed to run and grab a new vent valve from my local NAPA.
I installed the new valve and could have put everything back and run it but I’m a firm believer in trust but verify. Here’s the new valve activated closed and no smoke coming out.
Everything reconnected and ready to go.
Lastly while I had the Jeep on the lift I decided to address one of my two interference issues that I discovered during my last trip to Moab. I trimmed the pinch weld back a little more than I did 8- years ago and also trimmed, heated and reformed the inner fender splash shields.
Here you can see how much more room I have between the front of my rear tire and the inner fender. Should be plenty to allow full stuff.
My accurate measuring practice. I’m thinking about 2-3/4”. [emoji12]
Look at that, pretty accurate.
Thanks for looking.
Mike
