Sharp1227 Posted January 26 Share Posted January 26 We have a 2009 Mack Roll Off truck. We’ve replaced just about everything on it.. and we still don’t have any power. Has anyone else had this issue? If so, what did you end up doing to fix it? Please help!! 😩 Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/ Share on other sites More sharing options...
fjh Posted January 26 Share Posted January 26 16 hours ago, Sharp1227 said: We have a 2009 Mack Roll Off truck. We’ve replaced just about everything on it.. and we still don’t have any power. Has anyone else had this issue? If so, what did you end up doing to fix it? Please help!! 😩 Sorry to hear your having trouble how ever If you want help please post! SOME HISTORTY / The parts you replaced and how the situation developed/ And what tools you have to trouble shoot! Throwing parts at shit is expensive you need to do some trouble shooting first wild guesses don't always work as you have found out! educated guesses sometimes work ! Facts are much better! We are here to try and help how ever we don't have a magic wand or crystal balls the snapon guys quit making them years ago But Guys here will try and help if they can ! Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567744 Share on other sites More sharing options...
Sharp1227 Posted January 28 Author Share Posted January 28 Well the truck won’t get over 20 to 30 mph revs and idles like nothing is wrong but if you put it in drive and take off with the pedal to the floor barely goes turbo and vgt was bad had it rebuilt and a new vgt installed and calibrated has an inactive code for turbo speed sensor lost communication and a boost pressure code that’s only active when you rev it past half throttle let go it goes inactive has new turbo speed sensor new boost pressure it’s been deleted egr is blocked off cleaned all fuel lines ecm cooler been cleaned new fuel filters truck fire right up every time no problem doesn’t smoke or anything I have a laptop with software like Jpro and tech tool don’t believe it has anything to do with the delete this is the 3rd truck I’ve had deleted by the same guy with no problems but I guess anything is possible Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567933 Share on other sites More sharing options...
mrsmackpaul Posted January 28 Share Posted January 28 So if it isn't making any smoke at all your lacking fuel So the next question is, what controls the amount of fuel When the turbo failed did it dump it's bits and pieces in the exhaust ? What happened to the turbo when it failed ? Even though I most probably be able to help as this pretty modern Diesel is still diesel and they still need air, fuel and compression to work, even if they are swimming in electronic doodahs No smoke tells me no fuel Of it was mechanical I would say fuel filters It sounds like something is telling to not add fuel Paul Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567934 Share on other sites More sharing options...
Sharp1227 Posted January 28 Author Share Posted January 28 (edited) No turbo didn’t drop anything in the exhaust Veins were sticking in the turbo and the vgt something was wrong with the nozzle and it wasn’t communicating this is a 2009 mack gu 813 mp7 engine I kind of figured it was fuel just haven’t figured out what the cause is Edited January 28 by Sharp1227 Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567936 Share on other sites More sharing options...
Adkat Posted January 28 Share Posted January 28 Do both the turbo speed sensor and boost pressure codes go active when your into the pedal? Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567940 Share on other sites More sharing options...
Sharp1227 Posted January 28 Author Share Posted January 28 No just the boost pressure code goes active Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567954 Share on other sites More sharing options...
fjh Posted January 28 Share Posted January 28 1 hour ago, Sharp1227 said: No just the boost pressure code goes active have you checked the system for boost leaks cracked after cooler????? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567961 Share on other sites More sharing options...
Sharp1227 Posted January 28 Author Share Posted January 28 Yes that was the first thing I did Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567963 Share on other sites More sharing options...
Joey Mack Posted January 28 Share Posted January 28 Fuel pressure ? Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567965 Share on other sites More sharing options...
Sharp1227 Posted January 28 Author Share Posted January 28 It was like 43 psi at 1200 rpm’s I’m at the doctor as soon as i get done I’ll hook back up to it and give the exact reading pretty sure that’s what it was 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567967 Share on other sites More sharing options...
fjh Posted January 28 Share Posted January 28 Well being deleted it makes it a bit hard to tell but the fuel pressure sounds a bit low I would take it to your delete friend see if he can decipher what the issue is! I'm not a guru on these ! Is the truck on air ride? These sometimes derate for the air being dumped! Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567976 Share on other sites More sharing options...
Joey Mack Posted January 28 Share Posted January 28 Oh hell, its deleted... Yes i think fuel pressure is low as well. Quite low, i have forgotten the servicable range. Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-567978 Share on other sites More sharing options...
Mackpro Posted January 29 Share Posted January 29 Fuel pressure should be around 55 psi at idle and 65 psi at 1100 rpm. Test drive with Jpro hooked up and watch fuel pressure. If the pressure stays above 40 psi then it’s not a fuel pressure issue. If it’s 0 to 10 psi then it is a pressure issue. I would use Tech tool and do a VGT turbo test , it might just be out of calibration. It very well could be a bad delete too. If a 2010 program was put in a 2009 then the boost pressure would not read. 2008 and 2009 engine use a separate sensor for boost temp and boost pressure. On the 2010 and up the use a combo sensor on the back of the intake manifold. On the 2008 -2009 the boost temp sensor is on back of the manifold and the boost pressure sensor is towards the front of the intake manifold. Even though they look about the same Mack changed up the engines/software about every 2-3 years . DPF engines 2008-2009. DPF/DEF engines were 2010-2012. OBD DPF/DEF engine 2013-2016 then 2017 starts the common rail engines. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75066-mp7-no-power/#findComment-568071 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.