i have a 98 24v cummins and it pulsates at idle just woundering what it is or if its serious? any help would be nice.

 

First of all - THANK YOU for taking the time to post this in the correct forum.

Second - welcome

Third - what do you mean by pulses? Need more info on what exactly you are talking about. What pulses? rpm? If so, by ow much? Voltage? If so, by how much?

 

it like missfires it does it after its warmed up and when i come to a stop. it feels like the whole truck shakes for a quick second thenits fine the rpms dont really move that ive noticed

 

Crank position sensor maybe going out ?

Have you scanned it for codes?

 

i havnt lately but about a thousand miles ago i had my injection pump and lift pump redone because they failed. and so my mechanic went through and supposedly fixed everything hes neverd lied or steered me wrong befor so im not concerned i guess i should go get it scanned for codes tho.

 

That is always the place to start when something unusual or weird starts happening.

BTW, if you dont have a fuel pressure guage - it would be a good time to put one in. Other guages would be a good idea too. A full set of guages lets you know whats happening with the engine and helps a lot when troubleshooting.

 

i have a fuel pressure and boost gauge but its weird im on my third lift pump for the truck and everytime i get one the gauge is fine and after a month or so the fuel pressure does weird stuff like it will spike to like 25 or sometimes even 35 pounds my mechanic assures me its a crappy gauge ive had it check a few times but it still weirds me out so i really need to find a new gauge for it. anyother tips

 

Stupid question- AC on? It will cycle, and every time it does, the engine will sound funny when it first kicks on

 

Injectors maybe ?

 

Pop pressures or just wore out would be my first guess from the info given.