have had this truck for a while, 150 thousand miles
4" exhaust, "D" box, inj pump 1000 miles old, lift pump 1000 miles old
went to Columbus Ohio this morning pulling about 6000 pound trailer w/load
truck ran great. truck running at about 190 degree's
75- 80 MPH at any given time.. came home this eve ran like crap
first 50 miles basically had the fuel to the floor
lucky to get to 70 MPH. fuel pressure was at 12 LBS
exhaust temp was about 1000 degree's. boost was at 20
radiator temp was at 210 degrees
used twice the amount of fuel as I did in the AM
stopped after fifty miles checked for codes . was none
started this thing up and came to the house ,, ran great again
about to give up
any idea's are greatfull

 

have dealer check for codes not all the codes show up with the key method