Thread: Start of Injection Delay
View Single Post
  #8  
Old Thu, December 17th, 2009, 07:46 AM
cleatus12r's Avatar
cleatus12r cleatus12r is offline
F Your Yankee Blue Jeans
  
Join Date: Jan 2009
Location: Somewhere in Montana
Posts: 3,063
cleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to all
Default
Dave,


Bill and I had a discussion a few months ago about SOI Delay and there's a reason he wanted to talk me through it on the phone....it's complicated but not really at the same time.

It's Ford's way of compensating for the mechanical and electrical delays in the injectors at different oil temperatures and injection pressures.

The reason it makes sense to change this map is because for regular injection timing, you've simply got a map based on RPM and MFD. That's ok but there is no temperature compensation for the injection timing (save for the SOI vs. EOT but that's a fixed adder) except for the SOI Delay map.

The higher the value, the more the PCM is going to compensate and the more advance you'll see. It is time based (in milliseconds) so there is an obvious injection timing advance going on at higher RPM since time is fixed and RPM is not. See where I'm going with this?
__________________
Tuning, flashing, burning chips, and repairing all aspects of 7.3L Powerstrokes.
SEVEN 7.3L-powered vehicles in the driveway. Two didn't come that way from the factory!
Last edited by cleatus12r; Thu, December 17th, 2009 at 12:53 PM.
Reply With Quote