hi i had a replacement engine put in my vehicle and its now doing around 15 mpg i took the vehicle back to the local garage and they put my old injectors in it. they had engine had already used my old fuel pump put on it so they said it would be fine now as it would all be the same set up but now when the car is ticking over the car seems to shake the rev counter is showing correct idle limit and its still doing about 15 mpg and seems sluggish still.help
With 15 mpg I would expect to see a lot of black smoke from the exhaust. The pump timing could be retarded, that would make it difficult to start, quieter then usual and probably make it get hot, if it exhibits these symptoms check the cambelt.