Different speed and reference sensors in car..
 

Had a no start, and bought 2 new Facet sensors. I replaced the speed sensor (front), and haven't installed the rear reference sensor. Car now starts (was a bad ground above the bellhousing I found out), but some times it will fire right up no problems. Other times she will crank, kinda stop, instrument lights will dim, and then start up all in the same turn of the key motion. Is there something Missed while installing a battery, starter, the sensors, or not grounding right? Has anyone just installed 1 sensor that was different?

P.S. took the bottom metal part off that is closest to the flywheel, ring gear on the BMW sensor, and it look sjust like the Facet sensor. The Porsche and BMW metal sensors, that metal is just a sheilding it looks like if anyone wanted to know.