I know my 93s yj 4.0 was going to be bad on gas for around town, but I wasn't expecting 10-12mpg on a 20 gallon tank. Is there something that could cause this? And how could a test the part if its bad or not? Also I'm goin to the beach in 2 weeks and will report back with the gas mileage after a lovely 200 mile drive. Thanks for reading.
Ok. I thought I was the only one getting crap for gas, its expensive for these things to be a DD. Is yours lifted or anything? Mines completely stock(for now). I plan on going with a 4" RC lift and 33x12.50 bfg km2's or nitto mud terrains. So there goes more gas.
Tune-up time, in a big way. You should be able to get 17-18 MPG's with a mostly stock 4.0. I'm getting ~20 with the 4-banger. The O2 sensor is the #1 thing that determines your fuel mileage. Also check if the exhaust manifold is tightly bolted onto the head -- leaks here can fool the O2 sensor. Check for vacuum leaks by spraying some carbcleaner around the ends of all the vacuum hoses. Especially the fuel pressure regulator. Make sure the return lines aren't pinched at the tank. Check the air filter.
All these things affect the MPG's.
***--- Wrecking Crew member ---***
"I've prolly been around longer than you think"
I'm getting about 10 on a recently rebuilt 4.2/ Weber, nuttered, Team Roush and MSD 6 ignition. I'm using a fuel/air gauge so I'm pretty sure my mix is correct but I still have to take it to inspection to be sure. I'm leaning more towards my 3.07 gears and 31" tires as the problem. I have a 4 wire A/F gauge I'm going to install in a few weeks. I'm also going to confirm my engine RPM's and install a tach that will work with my ignition. I'm planning a frame off next year and if I feel the gears are the problem I'll do either an 8.8 or a D44 rear with 3.55's and regear my D30. Having said that I never expected my mileage to be much better than 15 anyway.
87 YJ The Original!
[QUOTE=Anticanman;14767780]It goes in that barrel you wheel out to the street once a week.[/QUOTE]
My build thread [url]http://www.jeepforum.com/forum/f12/new-build-thread-867043/[/url]