So i swapped my 46re out for a nv3500 and now it backfires when i give it gas idles just fine relaced pcm with it

 

Wrong PCM? Trash the crank sensor while doing the trans swap?

 

so i need a new crank sensor i know that there diff the one for a manuel is plastic and the one for a auto is metal three also 2 diff heights iv got the correct one in that matches the transmission thanks for your help man i need my baby back on the road

 

I know that feller is just all sorts of fun to get to, but, pull it out, see what it looks like. If it wasn't removed for trans R&R, it's going to at the very least be a bit tweaked.

 

Yep, if you changed the crank sensor before putting the bellhousing on, it won't run right. Have to put the bell on first, then put a new crank sensor in. Otherwise it will remove material from the end of the sensor usually.

Also, a factory sensor is suggestable. I went through random misfire codes with box store ones. They magically went away with a genuine mopar (NTK).

 

ill try that i did remove it and installed properlly but i will try that first it's only to bucks right

 

you might verify the distributor didn't turn either. The cam and crank sensors need to be within 10 degrees of eachother. (You can only check the sync timing with a high end scanner)