02 RD 688 E7 350 Engine Issues

[Dennis Hall]

I am new to this site and am hopeful to find some good mechanical help. Bought this one owner truck 2 years ago and ran with only minor issues. Currently has 321,000 miles on it. Did an extensive maintenance upgrade to it this past spring. (none having to do with the engine) My motor issues started thereafter with the start of it being a blown turbo, which was replaced. About a month later got codes requiring 4 eup's be changed and had them reprogrammed also replaced 2 injectors that appeared questionable. Think I blew out another injector shortly thereafter so I went ahead and replaced the final 4. Since this time the engine has developed a definite miss to it that is worse at lower rpm's 12-1400. Had the computer reprogrammed by mack and seemed to become more of a flutter than miss. Ran the truck 200 miles and the flutter went back to a miss. I intend to change the last 2 eup's and have the computer reprogrammed as well as changing the fuel lines, but question if this will totally correct the issue. I am seasonally employed and these issues have had a significant impact on me, however I look forward to getting this behind me and getting the truck right. My previous trucks were mechanical and I never had to be towed and this thing I've already been on the hook twice within 6 months and had the repair bill as well. Before the reprogramming of the computer tried a cut out test and no single cylinder was a for sure bet. If anyone would have any thoughts as to other directions in which to consider finding the problem I am all ears.

[RFCDrum]

It's a bad ground. Had this problem with the 01 rd tri axle I drove with a 460. Good luck finding it. Had the truck to Mack and this is what they determined it was. You would have to go over everything electrical. My truck would cut out or flutter as you mentioned. It would do it out of the blue. It could be something else but it just sounds familiar.

Cheers, Rob

[felicello122]

I am new to this site and am hopeful to find some good mechanical help. Bought this one owner truck 2 years ago and ran with only minor issues. Currently has 321,000 miles on it. Did an extensive maintenance upgrade to it this past spring. (none having to do with the engine) My motor issues started thereafter with the start of it being a blown turbo, which was replaced. About a month later got codes requiring 4 eup's be changed and had them reprogrammed also replaced 2 injectors that appeared questionable. Think I blew out another injector shortly thereafter so I went ahead and replaced the final 4. Since this time the engine has developed a definite miss to it that is worse at lower rpm's 12-1400. Had the computer reprogrammed by mack and seemed to become more of a flutter than miss. Ran the truck 200 miles and the flutter went back to a miss. I intend to change the last 2 eup's and have the computer reprogrammed as well as changing the fuel lines, but question if this will totally correct the issue. I am seasonally employed and these issues have had a significant impact on me, however I look forward to getting this behind me and getting the truck right. My previous trucks were mechanical and I never had to be towed and this thing I've already been on the hook twice within 6 months and had the repair bill as well. Before the reprogramming of the computer tried a cut out test and no single cylinder was a for sure bet. If anyone would have any thoughts as to other directions in which to consider finding the problem I am all ears.

i was told to always put the newest eup in the number 1 hole,because the ecm gets its info from the 1 spot. The cut out test you did i'm thinking was the wire test across the the eup terminals.

[staxx]

When the turbo went down did the intake get filled with oil ?

[Dennis Hall]

Oil pretty much went everywhere you didn't want it to. Everthing thing was taken apart and cleaned out good, air to air, etc. Plan on trying another cut out test to see if I can yet identify which cylinder. The only thing I noticed with the last four injectors that were replaced is that one of the center o ring grooves on the new injectors appeared to have a smaller, tighter groove for the o ring and you could tell it sqeezed the o ring more than the other 3. Another question I have would be; how important is it to consistently use Lucas or a like product for lubricity in todays ULSD Fuel? Sometimes I add some and sometimes I do not.

[staxx]

Need to make injector o-rings are in correct position big o-ring top of injector small o-ring next groove down and a tip washer . If fuel supply pressure is not up to spec 80-100 psi this will cause unit pump codes . The supply pump has gear drivin and the gear is prone to slipping as they get older . In the oil went everywere when the turbo went down its possiable that you might have hydro locked cylinder 6 with oil inturn might has bent the rod ..worst case .

[Dennis Hall]

Fuel pressure was confirmed by Mack Dealer to be within range. Dealer refllashed computer to VIN specs. The mechanic stated with cut out test that cylinder #3 made a slight difference but not enough to account for the issue. His remark was that the problem was like a ghost in that it was nothing definite. The injectors were all installed correctly, however the one as I stated the groove midway down the injector had a slightly smaller groove width in that it squeezed the o ring slighly more than the others. I stuck that one in cylinder 5 to ensure I could remember where it went, in case of needing to pull it again.