Mland917 Posted December 17, 2015 Share Posted December 17, 2015 Having an issue with my 427 after dealer installed new exhaust studs. The first time they started it, it blew an injector. They rebuilt injector but it only lasted 3 hours. Replaced injector, no power and engine sputtering.replaced all 6 injectors, no difference. Then dealer decided computer has gotten antifreeze in it from coolant sensor so they replaced harness and ecu. No difference. Got a super hot program from mack which actually helped a little, but still no power and low rpms (1200 to 1600). They checked epu's again and felt that #5 was bad so replaced it. Nada. Got 3 more data files from Mack..Nada. Mack said replace turbo. Made slightly more power but no fix. Truck tach actually goes backwards when taking off. Like the motor is surging. Now what? Quote Link to comment https://www.bigmacktrucks.com/topic/43146-mack-granite-427-problems/ Share on other sites More sharing options...
Andy 1983 Posted January 10, 2017 Share Posted January 10, 2017 Hi did u Ever fix the power issue with the Mack? Quote Link to comment https://www.bigmacktrucks.com/topic/43146-mack-granite-427-problems/#findComment-357860 Share on other sites More sharing options...
Andy 1983 Posted January 10, 2017 Share Posted January 10, 2017 I am having the same issue. Quote Link to comment https://www.bigmacktrucks.com/topic/43146-mack-granite-427-problems/#findComment-357861 Share on other sites More sharing options...
Mackpro Posted January 13, 2017 Share Posted January 13, 2017 Here's a bulletin on low power. This is only for the ASET, AI and AC engine. ASET low power checklist.pdf Quote Link to comment https://www.bigmacktrucks.com/topic/43146-mack-granite-427-problems/#findComment-358291 Share on other sites More sharing options...
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