Diesels hate the cold. My 2002 7.3 is no different and noticed a pretty extreme loping upon start up last winter. This was after I had service (complete fluid drop & refill) done to the truck and the tech refilled the crankcase with kendall. I use chevron delo so changed it out. Nothing like it was but still a little this winter. Any ideas?

 

Several guys have found relief for the romping after changing over to 5w40 syn. oil. Others didn't get relief until changing out IPR, and some still get romps when temps dip low enough.

 

You might also want to consider installing a high-pressure cross-over (HPX) line. It ties both high-pressure oil rails together to improve High-Pressure-Oil-Pump (HPOP) pressure regulation performance.

Consider the non-flexible stainless-steel-line type.

It doesn't cure it completely, but it helps eliminate it under most circumstances.

Pop

 

Rotella 5/40 Synthetic cured it for me. My truck romped so bad it would stall. Purs like a kitten now.

 

Mine was bad as well with Rotella 15w-40. I changed to 5w-40 and it starts fine now.

 

Cycle the glow plugs a few times before starting it. Bear in mind the glow plugs stay on much longer than the "wait to start" light. Depending on temps, let the glow plugs cycle 2-3 times (even more for really cold weather) for 60 second intervals before cranking. You can also plug in your block heater to help on cold starts. Most folks find using a heavy duty timer helpful (15amp variety) because the block heater only needs 2-3 hours to heat up to be effective, any more time than that and you're just burning electricity.
It would also be good to verify that your glow plugs and glow plug relay are working properly to give your truck all the help it needs to fire up in the colder temps.

 

I've just experience the Romps this am (only 26*F) only lasted about 10 seconds though. I also have the stainless steel cross over line installed. I'm really thinking about switching to Syn. next oil change. I'm running Delo right now and about 500 miles on oil change.

 

Synthetic oil is the key. Until I switched to synthetic oil I would get the romps at any temp below 20 degrees. Now, -20 degrees doesn't bother it.
JEV

 

Found out today that my #2 glow plug won't pre heat. Might have something to do with it.

 

In all of the 7.3's that I've worked on recently - if there's a glow plug drawing extreme amperage (not working/improperly working) it's not long after that I'm back in and changing out injector harness as well.

 

More good news?
In that case, what can I expect to pay for changing out all 8? If doing one, might as well do all with the 7.3 track record.

 

i changed all 8 last year in my 99, was real easy to do, other than a little bit of cussing.. i think i paid around 8$ per plug, for zd-11's (i think thats right) i done my research here first, but it was easy enough to do, just took a couple hours. if you take it to a shop I dont think they could get away with charging more than 2-3 hours labor, but watch their parts price, thats what'll get ya, and i bet an experienced tech could prolly do it in 1.5~2 hours easy.

 

Same for me here. Synthetic Rotella with quicker starts no romp!

 

ZD11 is the right part number. Do all 8 at once, swapping the glow plugs is simple but getting the valve covers off can be a pain so once you have them off it's better just to get the job done, button it back up and leave it alone for a while.