Blaine B.,
You stated "14-16........14 mpg city is what the XJ is rated at anyway. Do you mean 14-16 city (what I call stop and go)(?) or do you mean 14 city, 16 highway?
And where did you find that rating? What year(s) was that rating for?
I researched the older jeeps for weeks and could not find any definitive reference(s) as to what the original EPA ratings were for any of the older jeeps. That is why I asked others to post their MPG experience in this thread.
On another note, my last 2 tanks were 11.35 mpg before some of the recent fixes I have posted this past week, and I am about to fill up,...I have apx 1/4 tank (18 gallon Cap) left with 212 miles on ODO already, so it looks like about 16 mpg for 80% highway, 20% stop and go neighborhood driving on this last tank full. It has been about 70 F ambient this week here, and the engine has been running at 160 to 190 F (with a 165 F thermostat). I have noticed it running hotter this week, meaning leaner, meaning it finally starting running in closed loop at least part time! I was runnning Chevron regular gas. The prior tankfull had seafoam added to Citco regular.
I have never gotten over 12.5 MPG before since I bought it 2.5 years ago, so my recent efforts(1), correctly re-attaching (no longer wired backwards) the O2 sensor(1), the coolant sensor (never knew I had one tell a few weeks ago), and reversing the TPS/ECU connection (I had it backwards too) has finally got it running in the closed loop mode at least on the highway.
It has a 165 F thermostat, and it has started running closer to 190 F this week, versus 140 to 165 F last week and > 100 previous weeks. I think it is running hotter because it finally started going into the closed loop Renix mode where it runs leaner, and therefore hotter, inspite of the 165 F thermostat!!!!!!!
So I am starting to wonder if the 195 F thermostat is really required to reach the closed loop mode. This weeks test shows that a 165 F thermostat Renix 4.0 can reach the closed loop mode and continue to warm up beyond the 165 F setting. Obviously it will warm up faster, and reached the closed loop mode sooner with a 195 F thermostat.
Lastly, it still lacks the power it should have at 1/2 WOT throttle and higher. Still takes 60 to 90 seconds to reach 70 mph from 0 MPH at WOT. Also does not downshift at WOT like I think it should. So I am not done yet, but with it still lacking power, sip, etc., I am incouraged by the recent 16 MPGs.
I almost forgot, one more new thing! It has never, since the day I bought it ever pinged or knocked, even at WOT. Today it pinged for the first time at WOT! I think that is another indication that I had finally reached a closed loop lean fuel operation with the Renix. May be time for me to buy a knock sensor since the old one is physically damaged and unusable.
Mike McGinness
South Houston, TX
