cps now issues

so our 96 4.0 auto one morning would not start. so i changed the cps and wulla it started but ran rough as hell at first then after restarting a couple times ran fine. figured the computer had to relearn out how to run. but now in the mornings it has random missfires for the first 10 min. then runs fine for the rest of the day. The misfires are throwing codes and its random every cyl. any ideas

the missfires are the only codes its throwing by the way

Try cleaning the connector for the CPS/CKP crank sensor, use a little dielectric grease.

There is a chance that is coincidental to the crank sensor change.

also, make sure the crank sensor is seated tightly (don't break the bolts, though) on the bellhousing. The gap between the tip of the sensor and the flexplate/flywheel is important and needs to be maintained by the bracket that mounts the sensor. A larger gap can induce misfires that will be random in occurrence and may be dependent on thermal changes as resistance changes with temperature.

Shorty said:

also, make sure the crank sensor is seated tightly (don't break the bolts, though) on the bellhousing. The gap between the tip of the sensor and the flexplate/flywheel is important and needs to be maintained by the bracket that mounts the sensor. A larger gap can induce misfires that will be random in occurrence and may be dependent on thermal changes as resistance changes with temperature.

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Also, the CPS/CKP is mounted to the bell housing, while the flexplate/flywheel is mounted to the crank--make sure the bell housing to engine bolts are tight. Recent poster had a problem but only when he pressed the clutch pedal--yep, loose bolts.