gas mileage is very bad (worse than normal)

[aperseghin]

Ok here is what I have

88 2wd efi aw4 172k

I'm getting like 12 miles to gallon

I have upgraded the injectors to 4 port

I have changed air filter

New tps/harmonic balancer/serp belt/spark plugs

Oil change

 

I do have a leaky exhaust with no cat could that cause an issue?

 

What else should I do to it?

[mkbruin]

1) Seafoam. Or Mopar CCC.

2) plugs/wires

3) rotor/cap

4) fluids... all of them. Engine, trans, and diferential

 

Simple, easy, one afternoon and $100.

 

This is just a basic tuneup that should give you decent return.

[jimmy21669]

I do have a leaky exhaust with no cat could that cause an issue?

 

Yes. An exhaust, OEM, is tuned for the vehicle. I could get very scientific about pulse rates, etc, but you are causing resistance in your exhaust system which will rob you of horsepower, thereby causing you to use more gas.

 

Hope that helps.

[dasbulliwagen]

Do you have bigger tires than stock? If so that could cause the speedo to be off, and thus your milage numbers incorrect, but I'm not sure which direction. Its possible your speedo gear could be wrong if the trans has been swapped and it originally had different gearing in the axles, or maybe your axles have been swapped to different gearing and the speedo gear wasnt changed. There are a bunch of things that could casue an incorrect number, and with all youve done already, its time to look into these areas.

 

ALSO... dragging brakes, incorrect alignment, slipping trans, low tire pressure, can also cause poor fuel milage.... check it all! Good luck!

[Bigbike]

What are you guys getting for fuel economy? Normaly.

[whowey]

Do you live up north or down south???

 

Winter gas is upon us... with all that entails...

[jimoshel]

'89 XJ,4.0, AW4, everything stock, 15MPG.

[High2by]

It could be a lazy O2 sensor. That could cause bad mileage.