Gas Mileage

[Turtle]

1043575

Hello All! Just recently my gas mileage has been sky rocketing and I cannot find the cause of this. I thought perhaps it had something to do with my air filter, but replacing that has not helped a bit. As of now I use a 1/2 tank of gas to get to work! ANY suggestions will be very much appreciated. (I have an 88YJ straight 6 )

Thanks in advance!

~E [addsig]

 

[hi_c]

1043579

Unless you work is 80 to 100 miles away, I'd say that you have a leak. Have you checked your gas cap to make sure it's on tight? Have you checked your inline fuel filter to make sure there is no leak there? Then trace the fuel lines all the way from the tank to the engine (either fuel injection or carbuerator, not sure what you have). Does it idle high, say 2000 or more rpms? Check for vacuum leaks. But usually the only thing that will cause that much wastage is a leak. sorry dude.

[addsig]

 

[MudderChuck]

1043584

Just went through that with a buddies 90 YJ. Turned out to be a combination of things. The first and most major was that the vacumn line fell off of the vacumn resevoir, under the battery. Made for really bad gas mileage, rough and erratic idle. Second was that someone tried to adjust the carb. idle screws, and missed by a mile. Third was a stuck PVC valve. And fourth was it was timed at idle, not at the RPM recommended on the sticker under the hood. Fifth he had a fuel drip at the filter and the carb. was seeping some. Tightening the carb screws and running a load of carb. and injector cleaner through the gas tank seemed to help some also. Had a leaky gas cap that spilled some when full and accelerating. Doubled my gas mileage, without a major tune up. Setting everything up to the book recommendations also helped. Idle, high idle, choke, timing etc.[addsig]

 

[Turtle]

1043592

Thanks hi-c and MudderChuck! Your suggestions will definately help out with the scope.

With appreciation~E [addsig]

 

[Tug-n-pull]

1043605

If you have not gone to a K&N filter you can add to your milage and power with this addition. Also if you go to a good flow thru exaust system say a cat back, flow master, or even an old fashion glasspack. will help. Let the engin breath and the milage will go up. Tug[addsig]

 

[Tug-n-pull]

1043607

If you have not gone to a K&N filter you can add to your milage and power with this addition. Also if you go to a good flow thru exaust system say a cat back, flow master, or even an old fashion glasspack. will help. Let the engin breath and the milage will go up. Tug[addsig]

 

[craigmpak]

1043608

What kind of mileage is everyone getting anyways? I'm curious because I find mine a little hard on gas about 240 miles (400 kms) to a tank (92 YJ, smaller tank, 4.0 L)



It seems to run fine and I don't rev it at all ....... seems a little low to me.



Craig[addsig]

 

[Jeepr89]

1043613

I've been getting anywhere between 14-17 mpg in my 89 YJ with a 258. The number has been down towards the 14mpg side since it started getting cold.

[addsig]

 

[hi_c]

1043625

Craig, 240 miles to the tank is excellent. I only get 210 miles to the tank on a good week. And I only have a 4 cylinder! So count your lucky stars.

[addsig]

 

[TheApexTheory]

1043627

I get 14-18 miles a gallon. Of course I only have 28 inch tires

[addsig]

 

[idrthrbfishing]

1043654

I was getting about 10-12 with a 97 4cly. Found a gas leak under the hood one day in the rain, now I get 14-21 depending on how much time I spend on the beach, also turning 30.5" and that hurts a little.[addsig]

 

[jeepthrills]

1043732

Milage???



1984 CJ7 258 weber carb 32" tires 3.31gears 13-18mpg



1984 CJ7 360 2bbl 33" tires auto 4.11 gears 8-11 mpg



1989 XJ 4.0L auto 31" tires 3.55 gears 12-15 mpg



1994 XJ 2.5L 5 speed 30" tires 4.10 19-26 mpg

[addsig]

 

[MrBill]

1043768

I get 15-17. Slightly worse when they "oxygenate" the gas in the winter...

4.0 TJ, 5-speed, 33" tires, 3.73s...



Doesn't help that I often rev it up to 3-3.5K before shifting...

[addsig]

 

[jackal]

1044004

Stock 78 cj7, 232 ,3 speed, 2 bbl carter BBD ,10-12 mpg.







Jackal[addsig]

 

[far_right]

1045101

i get like 11-12 w/ 258, weber carb, runs a little rich i think....[addsig]

 

[PASmokeater]

1045103

I get about 19 to 20 mpgs with a 4.0 TJ 5 speed with 30" tires, but most of my driving 90% is highway[addsig]

 

[jcooper]

1045104

97 TJ 2.5L Manual ~20mpg. Drops to ~17mpg in Cali, they do something funky above and beyond

oxygenating the fuel. I wonder if the eco-nazis realize pushing for additives that "clean" the emissions don't

help if it makes the vehicle burn more fuel...



As for miles to a tank, if you have the 15 gal (YJ orTJ) you can cut a tube to increase the capacity to 19 gal. It's

more of a bitch with the TJ. Chrysler got smart when they saw YJ owners would pull the hose out of the

relief neck and cut it. So TJs have to drop the tank, pull the fuel pump, reach inside, and cut the tube. Can

you tell I just did it last weekend? Its amazing how such a simple thing gives so mush happiness. Yeah, I

know, simple minds, simple pleasures.



Cooper.[addsig]