9 mpg! *kicks Jeep again*

[speeddemontbn7]

So, driving my heep conservatively, i'm getting 9 mpg. I have an 87 jeep cherokee 4.0 4wd. When my friends drive behind me they say my exhaust reaks like a garbage truck full of garbage. My tail pip is covered in excessive amounts of black soot. Also, i have to pretty much keep it on the floor to reach 80 on the highway..... Any suggestions?

[AlohaBra]

Running rich huh? any codes or CEL? Test the Map sensor...

See if you can use this download:
http://www.dua1.com/AdminFiles/Jeep/....injection.pdf

[1996Chreokee]

WHen you get in and turn the key to the on position does your check engine light come on? just making sure the bulb is functioning?

do you have a check engine light on, if it does work?

a bad oxygen sensor can kill your mileage but it would trip the check engine light. Your vehicle has 2... there is a small chance it would not trip the light depending on your driving habits...

you can go to autozone or an advanced auto and they will scan your computer for you for free...

let us know

[speeddemontbn7]

It is an 87 cherokee therefore it has one O2 sensor and it utilizes the renix system (pre 1991) and has no check engine light. I would like the check the map sensor. but i dont have a place to get the chart regarding what voltages coorespond with what vaccum.

[AlohaBra]

I don't know if there is a chart. But maybe you can just use a vaccum pump and make sure that the variable output is working. Use a digital voltmeter.

Also found this for you on a search:
http://www.automedia.com/Sensor/Trou...cr20011001mp/1

*(Edit was done on this reply because I didn't read it all completely.)

[speeddemontbn7]

Some kids i know that are in school for auto are going to look at it monday in their "advanced diagnostics" class... Hopefully they will turn up something. I will try and check the map sensor this weekend.

[AlohaBra]

Edit was done on above thread. (Bump..just to make sure you got notified.)