Sapp Posted May 17, 2021 Share Posted May 17, 2021 I have a 04 Mack Vision. Put it in shop for a water leak. However when I got it back it had a miss. Had injector replace ,had cam check, and a vgr aculater put on. It only seems to miss when loaded and on the high side. It has a e7 motor in it. What else can this issue be? Quote Link to comment https://www.bigmacktrucks.com/topic/66713-missing-on-top-side-when-loaded/ Share on other sites More sharing options...
JoeH Posted May 25, 2021 Share Posted May 25, 2021 I've had fuel filters cause this; replaced them twice a few days apart and it cleared up. Almost sounded like Jake brake kicking on lightly. Fully mechanical '95 E7-350. Quote Link to comment https://www.bigmacktrucks.com/topic/66713-missing-on-top-side-when-loaded/#findComment-474268 Share on other sites More sharing options...
Joey Mack Posted May 25, 2021 Share Posted May 25, 2021 I'm guessing this engine is an ASET CEGR engine? if so, has the air filter for the VGT turbo been replaced and has air flow to the VGT actuator been checked? The actuator can also stick, causing poor operation. that is an easy fix.. The filter is below the starter, and there should be a "T" fitting plumbed in by the treadle valve. it is probably silver in color and it has a hexagon shape to it and a red rubber vent button on it, unless it rotted away. The fitting is a pressure protection valve that opens at around 85 P.S.I. when this system fails, you will have power loss and what you described, due to the VGT not operating correctly.. Good luck, jojo Quote Link to comment https://www.bigmacktrucks.com/topic/66713-missing-on-top-side-when-loaded/#findComment-474273 Share on other sites More sharing options...
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