'06 Series 60 runs rough when cold.

i'd go for the mr. muscle instead. it's $20 and treats 750 gallons.

i use it whenever my mileage starts dropping. i see improvement in running and mileage on the first tank.

it's as if the injectors are plugging up a little.

you can find it at any of the local truckstops. the big chains dn't sell it.

 

Excactly what I was thinking. It could be that you are loosing pressure in the fuel system. Have a look at the check valve at the back of the head, maybe you're loosing fuel pressure in the head.

 

it is most likely your fuel lines. you will know something when the weather gets cold. a fuel line sucking air will make it hard to start only in cold weather. if the back check at the back off the head is bad, truck would be hard to start after sitting NO matter what the temp outside. the demand on more fuel when driving would not be any different, the fuel pump usually pumps more than enough to compensate for any air, that's why you have a fuel return line, for unused fuel.

 

I am not sure which fuel line it MAY be. I was told on mine it could be the suction line. that is my line from my out on my davco to my pump. replaced that & it made no difference, so I replaced both lines going to the back of head one with the orifice in the brass elbow & back check & the return line also. but on mine I also have a procheck aftermarket device designed to keep air out of sys, it had 1/4 & 3/8 lines & I replaced them too. the only line I did not replace yet are the 2 line that come from the fuel tanks.

 

the fitting should be o.k.

 

replace the lines going to the back of the head & work your way back.

 

when you start up after couple days do you still have air pressure ? VPOD uses air to control vanes for turbo. Needs at least 60 psi before [jet sound] begins. Could just be normal , easy check is air system down and start up and see if roughness is back after warm-up