1999 Mack rd688 fuel issue code8-4

[KHBtruck22]

Truck has code 8-4 was leaking fuel from return line behind the eups change that line still had a code so then Changed the eup for cylinder 4 and it’s still has a misfire , and  has no power.

if anyone can help out or suggest what the issue can be any help would be highly appreciated . Please and thank you! 

Edited October 3, 2022 by KHBtruck22

[fjh]

2 hours ago, KHBtruck22 said:

Truck has code 8-4 was leaking fuel from return line behind the eups change that line still had a code so then Changed the eup for cylinder 4 and it’s still has a misfire , and  has no power.

if anyone can help out or suggest what the issue can be any help would be highly appreciated . Please and thank you! 

Is the code gone? Can't help much with out more info! You may have a bad injector ! try crackin injection lines one at a time see which one does not effect the engine rpms! post all of your symptoms is the engine smoking if so what colour is the smoke!? 

[Joey Mack]

cracked wire for the EUP?? The last one I built also had worn EUP lobes,,  litteraly worn the lifts right off the lobes..  Did you pull the EUP roller and inspect it and the cam lobe? 

[KHBtruck22]

It was the wire, thank you!