Loading up when cold

My XJ has a problem. When I first run it in the morning, at any level of throttle except WOT, it seems to bog down sparatically while going down the road. It does it at any speed, but only for about 6-7 minutes of running. Do these run on closed loop while cold, then switch to open? It throws no codes, so I'm thinking the FI system is operating correctly. Oh yah, sometimes it will backfire through the intake as it bogs, clears out, then runs good for a while. Without the help of the CEL I'm puzzled, and hope someone else has had a similar problem. It's a '91 H.O. with auto. When I leave work in the afternoon I have no problems. Could moisture in the dist. cap cause these symptoms? TIA

Start by cleaning ALL grounds under the hood of your XJ. The one from the head to the firewall is also very important. There's a bunch of wires grounded on the rear of the passenger side of the block. Maybe some in front of the distributor also. After that if you still have problems replace the coolant sensor in the thermostat housing (I think yours has one) and the intake air tempersensor in the intake manifold.

JoBo