erratic idle

[bill75]

my 94 xj idles erratically mainly when cold. sometimes at a stop
the engine lopes. took it to garage they changed the distributor cap and rotor didnt work then they changed crank sensor still nothing. now they want change fuel pump and filter. can anyone help me diagnose the problem.

[Runnin'OnEmpty]

Bill, try cleaning the throttle body, in the area where the throttle plate meets with the bore. Carbon deposits tend to build up there, and result in an erratic idle.

[Judd W. VA]

I would also give the shop some crap for 'replacement diagnosis'!! Just to replace stuff hoping to correct a problem is not the way to do it!! Don't go back there-

[bill75]

thnk for the response. the tthrottle body was dirty cleaned it seems to be running better. thnx.

[XJ-ARMOR]

Poor O2 sensor reading may also cause a rich/lean condition which can cause the problem you describe. Maybe time for a new O2 if its been many miles since the last change. -Steve

[xjwoody]

Cherokee America has a good article on cleaning the theottle body
http://www.off-road.com/jeep/cherokee/xjtech/engine/tbody.htm
You need to replace the O2 sensor, too. Don't even think about it... just do it.