1996 Jeep Cherokee Country. Been running very lean, 6mpg lean.

Intake manifold was cracked, replaced it. Did a tune up. Replaced fuel pump and filter. Still running lean, horrible gas mileage still at 6mpg.

Took off the map sensor to check it out. I'm not 100%, but I could swear the hose wasn't in the sensor since it fell right off was the screws came off.

I cleaned the sensor with some air and paper towel, and hooked it up ensuring the little hose/valve were connected.

The Jeep started surging the second I cranked it. Undriveable surging. Disconnected the electric from it, and the surging stops.

This has to be a bad Map sensor, right? No vacuum leaks that I can find, and I know the MAP can give the lean error/kill mpg. Anyone else experience this or have insight?

 

no check engine light
?

 

No. But it gave the Lean Fuel code when I had it hooked up. I'm pretty sure my check engine light is inop.

 

Error code P0171.

 

Try resetting the computer. Remember after you change parts or clean stuff ot takes a while for the system to learn what you did to it

 

So disconnect battery for a few minutes?

 

Take battery clamps off and hold them together for 30sec and it'll flash the computer. It'll go back to factory settings and it may after that it'll learn you.

 

Yes leave the battery unplugged for a few min. Over night if you want. I would have cleaned it up with brake parts or carb cleaner than blew it off

 

Disconnected the negative cable. We'll see what happens in 30 min.

Thank you for the help. Hope this does it.

 

Did you hold the battery cables together for 30 sec? That will reset it back to normal fuel air mixture unless it is the map sensor

 

No. So hold the positive and negative together? Sounds dangerous. Though I guess not really since they aren't connected to the battery.

You sure about this?

 

I have never done it before but I heard of others doing the same thing I imagine it wouldn't matter as long as the motor wasn't running

 

Just don't let them touch while connected to battery that's all. Disconnect them close your eyes touch em and smile

 

Eh. No offence, but I think i'll just leave it disconnected. Also known as wife said don't you dare.

 

Don't worry about it just hopes it works out for ya