Join Date: Aug 2001
Location: Saskatoon, SK
Feedback Score: 0 reviews
Re: 7.3 engine timing
The question you ask is fraught with pitfalls.
On ANY of the HEUI engines, there are two very different values for "timing". The first is the electronic signal that TRIES to start the injection event. The computer tells the injector to fire, and then after some period of time, the fuel gets delivered to the chamber and then it actually DOES begin to burn. There is no hardware to communicate that event in real time (i.e. closed loop) to the PCM to let it know that it actually happened, so there can be some HUGE variation, and thus the one, big soft spot in HEUI technology. Add to that the split shot injectors from '99 on, that have even more mechanical assumptions to control injection.
Because of these things (we can only assume) the PSD is shipped with relatively late timing (to prevent some of the cackle and knock problems from getting out of hand). They usually benefit from increasing the lead of the injection signal.
You can change timing in a number of ways (all software related - even the EOT mod is just fooling the computer), but you could only know where it actually "fires" by measuring cylinder pressure vs. crank angle.
Hope that helps.
2000 F450 Lariat 4x4 tractor, rebuild at 200k in '12, Air Dog, Reg Mod, HX & HP all in hard SS lines, bypass filter, Banks Power Elbow w/3.5 dp, no intake heat, CCV mod, AIS (w/extra hole), some big Alliant single shots, GP indicator LED, custom 4" exhaust, 4" USG exhaust brake, custom alum. rear diff cover extension (dipstick & temp), Detroit locker, ESPAR D5 aux. heat, custom alum tow deck and fuel tanks, Bushwacker 1 1/2" flares, 9k winch, gin poles, JWSpeaker 8900 LED headlamps in XL grille, Lightforce 240GT (still Halogen, but VERY bright), Hella Micro DE HID fogs, KW = vision plus (Isspro) instruments, more to come & lots of other diesels