Took my perfectly good running CH E7-427 to the Mack shop for a simple clutch job . 740k miles , had it for 4 yrs , know history of truck , came from this dealership new . Anyway , got the clutch done , machined flywheel , new rear main seal , changed seal on front diff output shaft and everything else seemed ok . $3500 and change later we head to the farm . Eight miles to home never went over 1500rpm bobtailing etc . Couple days later I deciede to haul couple loads of gravel , 15 mi round trip . Take off , get up to 18-1900rpm starts missing , cutout etc , start to wonder what's going on . Pulls good though up to there , 34-5 #boost going up hill . Get to stopsign , shift down , range and splitter in low , let out clutch , no go . They routed the air line to the stationary neutral valve right under the exhaust pipe , burned through left range go into neutral . They wanted to tow it , but came out and fixed it on sight . Next day I hauled the other load and took the truck back to the shop . Told them about the rpm problem and also the clutch brake wasn,t adj properly . Called me next day said truck was done . Said the tach sensor at flywheel was a little off on ohms reading but it worked and would probably be ok . Took off again , started cutting out at 17-1800 now and was worse than before . Got off at the next exit and headed back to shop again . They changed the flywheel sensor didn't help and really sounded worse , now it smoked and missed worse when you reved it . Next they changed out the sensor on the injection pump . That didn't work either , now they say the inj PUMP IS BAD !!!! That sensor was changed last July when the econovance solenoid was replaced . Now what I can't figure out is how a SUPPOSEDLY PROFFESSIONAL SHOP at $85/hr can really f*******p a really nice good old truck . Could they have shorted out something in the wire harness or something . I said what if a pump rebuild doesn't work out , we are at a stand still as or Fri PM . I'm not a proffessional mechanic but I have done lots of wrenching here , Chevy , Deere engine and trans , and I do know what's going on . I do know about inj pumps , the old mechanical inlines and rotaries ,been tractor pulling for 40 yrs . I think they MESSED UP . I'm going there tomorrow AM and try to keep COOL but it's gonna be hard to do . SORRY FOR THE RANT !!!!