I had a similar issue on my VP when I dropped in a fresh engine 3 or 4 years ago. it wasn't until i got my wheel alignment done that its broke down under load. was fine driving normal then breaking down under acceleration and was terrible up any hill til I pulled over near a bus depot with a repair shop as back.
I found that I forgot to do up the 7mm bolt on the dfi plug and it must of got knocked loose by the guys doing my front end alignment as they had to adjust my strut tops.
went across to this bus depot and borrowed a 7mm socket and ratchet and away I went again lol.
