I have a remanufactured injection pump it was $1,100 I install it on my truck I was getting 21 miles to the gallon now getting 17 miles to the gallon does anyone have any ideas the injection pump rebuilder said he doesn't know any reason why it should have changed does anyone have any ideas Thank you

 

dont have any idea. thats alot of difference

 

Who rebuilt it? Were they a Bosch Authorized rebuilder? I would call the manufacturer and ask them whats up.