This truck has a well service unit built on it, so it spends most its time revving up and down all day everyday. Engine has 35,000 hours and doesn't use any oil between changes. This pump was obviously a mack reman and not original. Over months it has slowly been getting worse about dieing when you let the throttle off. Then hard restart. Once it ran 4 hours there was no keeping it going the rest of the day. It would also idle up, not sound right, inconsistent speed, etc. I replaced all fuel lines, transfer pump, overflow valve and put a clear line with gauge between outlet on transfer pump and inlet on last filter. No air and 38 psi or higher at all times yet die and hard start.i set timing which was 1 degree off on truck and pulled injection pump. The shop I took it to tells me it's got out of spec sticky wore out plungers and barrels. I've wasted a week being down while they tell me they are looking for parts but unable to find. I'm a diy kind of person and I work on lots of my own large equipment this is the first time in 13 years that I've had a problem with this truck and my first time pulling the pump on a mack. Tomorrow I will get the tag from the pump shop and call some of the places suggested. If I find someone who can fix it I'll go pick it up and ship it. This truck is my only income, it's been a tough 4 years. I need to get back to work and if I have to I have an electronic mack I can swap motors to get it done but would much rather just fix my injection pump. I appreciate the help and any suggestions on places to call. Thanks
