Rough Idle after new cam install

[GTX]

The cam in my dads 96 was just replaced and now it idles rough and smokes badly when running down the hi-way between 70&80. It is going back this morning to have the valves adjusted again.



Any ideas? Could they have gotten the gear on the injection pump not lined up right?



History: 109,000 miles

The gear on the vacuum pump broke 3 teeth off and that chewed up the cam gear. When the cam was removed to put a new gear on they found some of the lobes were starting to get rounded off. On most of them the peak was rounded off and on 3 of them the metal was flaking off. They also put in new lifters and vacuum pump.



Thanks

 

[Strick-9]

They should have retimed the pump after the cam install. They might have just hoped that it didn't move and replaced the camshaft. Depending on where the pump stops, sometimes it will jump a bit.



But I have also seen a cam installed without matching the line up marks on the crank gear. The cam/crank was out by 4 or 5 teeth. I can't remember exactly. Surprisingly, that engine ran rather well.



It all depends on who does the work. Was this a dealer?



-Chris

 

[GTX]

No it was not a dealer. Since it is out of the 100k and 5 year warranty nether Dodge or Cummins would help. It was a Diesel shop in Denver.



I think they did not get the pump gear lined up right. The valves were checked and they were adjusted ok.



Thanks

 

[Strick-9]

Since our P7100's don't use a keyway, the timing of the pump gear itself is irrelevant.



You can put it anywhere you want with respect to the cam gear as long as you retime the pump afterwards.



Do you have anyone that can find the plunger lift @ TDC?



It seems the shop that did the work would be more than willing to check pump timing if there is a problem.



It's very likely that the pump rotated slightly while removing the cam and they just put the new cam in without retiming it.



Have you expressed your concern to them?



-Chris

 

[GTX]

Chris, Thanks for the info



We will go and see if they can time the pump, if not then go somewhere else and send them the bill.



Thanks again



Rick