Notice that the engine really starts to surge harder (at idel does not surge under load) when the it is at normal operating temps. and the ambient air temperarture is around 80 degrees or warmer. Since the fuel is used to cool and lube the injection pump could warm fuel be showing a problem that otherwise would not show up? When the ambient temps are lower there is only a slight surge, almost undetectable. I picked up a map sensor today, haven't decided to change it out or not.

 

bkay. Where did you get your MAP sensor from & how much $ did it cost you. I am in need of one right now.

 

Local Freightliner dealer. $44.00 plus tax. It takes a 1 1/4" deep socket to get it out six or twelve point. You will need the engine model number for them to get a match.