My '87 Weekender bucked and kicked like a brahma. I finally narrowed it down to what I was hoping it wouldn't be, the ECU. After a $450 rebuild the van runs great (i'm sure also attributable to the troubleshooting i did beforehand). Before the ECU was rebuilt I got a solid 18-19 MPG. Now with the rebuilt ECU I get 14-15 MPG on the highway!!! Has anyone seen this before or have any ideas?

Many thanks,
Matt
'87 Westy Weekender