87 xj problem
I have a 87 cherokee I bought it not running,well I got it running but it idles rough and is running way to rich.It smokes all the time but it is gas not oil smoke.It cranks fine but if you wot. it pops back through the intake and then dies but cranks right up. The only sensor I have replaced is the tps.It helped with the idle,I have tried the search but no luck. Thanks For any help.
Member
Joined: May 2010
Posts: 167
Likes: 0
From: San Antonio, Texas
Year: 1987
Model: Cherokee
Engine: 4.0L (Renix)
it wasnt running when you bought it...but you said you got it running..how? the tps itself, caused it to start running all of a sudden?
I think we're missing some installs here...
what about a fuel filter, plugs, wires...if it wasnt running for a while, probably wanna do all the simple tune up stuff first, make sure youve got good compression in all 6 cyl
I think we're missing some installs here...
what about a fuel filter, plugs, wires...if it wasnt running for a while, probably wanna do all the simple tune up stuff first, make sure youve got good compression in all 6 cyl
Member
Joined: Nov 2009
Posts: 198
Likes: 0
From: Fallbrook, CA (Commufornia)
Year: 2001
Model: Cherokee
Engine: 4.0
Check the vacum line running into the map sensor and check the map sensor itself. That will cause your Cherokee to dump fuel as yours is doing. Attached below is a link on the test procedure for the map sensor, read almost half way down the page.
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
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Member
Joined: Nov 2009
Posts: 198
Likes: 0
From: Fallbrook, CA (Commufornia)
Year: 2001
Model: Cherokee
Engine: 4.0
Did you check your supply voltages comming from the ECU. Your supply voltage should I belive be 4.5 to 5 volts at terminal B on the ECU harness side. Not terminal B at the MAP sensor side of the harness. The vacum line is shown in the picture of the link that I sent you a couple of posts back it is shown to the left, and behind the harness in the picure that plugs into the MAP sensor. If your ECU is not supplying the correct voltage to the MAP, or there is no vacum supplied to the MAP then you can put new MAP sensors in all day and it won't help a bit. I went around and around with the same thing on a friends '87 XJ and what happened was the vacum line to the MAP on his car either got pulled out by us working on it or it just fell out and was eventualy found sitting behind the block kind of out of our line of sight. Anyhow we finally found the vacum line pluged it back in and problem solved. Maybe because you can't find the vacum line on yours, maybe the same thing hapened and your vacum line fell out and is sitting behind or on top of the motor. I don't know, just trying to think of possible issues.
Did not check the volts,got another peice of vac. hose and ran it from the map to the vac. port on the intake.This might be a stupid ? but is the vac. port suppose to blow or suck?
Last edited by Georgia Boy; Oct 21, 2010 at 08:28 AM.


