zeault Posted January 25, 2022 Share Posted January 25, 2022 Hey there folks, I got a used mack CX with an etech. The motor is a factory reman built to the original's 2001 spec. Has about 625k miles. Seems mechanically sound. I can hear just a little bit of a misfire during idle. Can't hear it while revved up. Other people say they don't notice it but I know its there, and the ECU agrees with me. I don't have the software but the lightning bolt blinks 8-3 for EUP. Doesn't happen all the time. Mostly just when started up cold. I have had the lightning bolt come up on the highway though, and sometimes I think I hear it when I hop out and its idling hot. Noticed that when it happens there's some white smoke out the blow-by tube, but when it stops the smoke goes away. It does smoke out the blow-by tube when its good and hot regardless of the knock. I assumed that was normal for 625k. I probably have enough money to take it into a shop, but I'm a new owner/operator and I want to get more comfortable working on this motor myself. Took the heat shield off and noticed the EUP #3 looks like it's been replaced before. It looks wet in the picture because I used PB blaster on the harness screws. I got the VMAC workshop manual 8-211 but its for the later ASET engines. Can't find the 8-211 for my model year. I did some of the continuity tests anyways and they checked out okay. I think I'd like to do an injector cutout test. If I try disconnecting the wires from the EUP while the motor's running is that gonna hurt anything? Then maybe I'll try swapping it with another EUP in a different cylinder and seeing if the problem follows? I'll have to take those high-pressure lines off. Do you have to bleed/prime those when you put them back on? Never done it before. Oh and it looks like I got a head gasket leaking onto #3. Maybe that caused the EUP to go bad twice? Or maybe the misfire cause the gasket to fail? If you've got any wisdom or advice I'd really appreciate it. Thanks Quote Link to comment Share on other sites More sharing options...
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