would it be possible that there's a vacuum leak somewhere? not sure if that would throw a code or not.

 

You would hear it... I believe...

 

A buddy of mine was stuck in the mid 11's mpg-wise. We looked over/cleaned and replaced all the parts you listed and nothing helped. Until he noticed his motor mount on the drivers side was pretty worn. Not broken completely, but well on its way. We replaced them with brown dog mounts and oem replacement for the trans mount. He jumped up about 1.5 mpg immediately. It didn't magically give him 20 mpg, but with our rigs every bit helps right !

 

Hmm... Is your jeep coming up to temperature ? Running in the 195 210 area... If its running to cold that will also have bad gas mileage ...

 

Interesting! I don't think mine are in great shape, but this could explain why i have such poor economy in the city (say 16 in the summer) but can pull 28 on the highway, stocker 5-speed.

 

A lot of car have "adaptive driving" meaning that a car will learn its driving conditions and adapt to either fuel milage or performance. you can reset the ecu(by doing this, you also reset the fuel trim). give it a try and see what happens

 

trans mount was replaced and took care of the banging from the exhaust but no mileage improvement. Motor mounts are for sure on the list of one of the next things. the ECU was reset when the 02sensors and injectors went in. and have run two tanks since then so definately enough time to get the computer to relearn the trim

Temp is good, even when running the computer to take a peek at live data its running steady about 200-205, so i know the computer is seeing the correct temp.

this one has got me puzzled since all the normal culprits of poor mileage have been taken care of,

 

It is certainly serviceable. You just have to drop the tank. I have plans to replace the whole thing due to my gauge jumping around and not really being accurate.

 

you are right is is serviceable but does anyone really want to drop the tank for a filter? I understand your position being how the gauge is off or not working correctly. What i was saying is that in a normal maintenance schedule of things changing the fuel filter isn't really a feasible idea.

 

True. There's a youtube video somewhere of a guy that takes the whole pump assembly apart, but aint nobody got time for that!

 

Heard that! But I'm subscribing as well. My 96 is riding on 2" of lift and on the same set of tires. I'm around 14 mpg. My 88 I was kicking it with 18 mpg's.

 

How was your mpgs before those 784 injectors? I heard their flow rate is to high and even after the ecu it'll spray too much fuel

 

In winter months? Be happy with that, that's not bad at all

 

How can a bad motor mount reduce MPG?

O2 sensor is often blamed for bad MPG.

 

honestly it hasn't changed at all, still crappy!