AUSJEEPOFFROAD.COM Jeep News Australia and New Zealand - View Single Post - JK CRD fast cranking not starting, then starts OK after turning key on and off 3x
View Single Post
  #3  
Old 17-04-2018
rob8888's Avatar
rob8888  rob8888 is offline
Senior Newbie
 
Join Date: May 2007
Location: Wellington, NZ
Posts: 55
Likes: 3
Liked 3 Times in 2 Posts
Default

Quote:
Originally Posted by Classic Boy View Post
The following more general common rail info, rather than specifics of the JK engine.
The faster starter speed is probably lower compression due to any reason other than no fuel, being injected, as the injection of fuel adds to the compressed volume and the combustion resistance particularly when pre-injection or sometimes called pilot injection occurs.
It maybe an issue with a sticky shutoff solenoid valve/ pressure regulating valve not initially opening fully or maybe the high press pump is not building pressure rapidly.
Thanks. I find it interesting that the easily identifiable cranking speed difference is due to addition, or lack of, fuel, but I guess that under compression the air volume is relatively small and oil non-compressable.
__________________
Black 2010 CRD JK unlimited, after KJ 2006 CRD LTD (totalled by speeding driver). BLOG