HT4100 4.1, 4.5, 4.9 Discussion, injector duty cycle in Cadillac Engine Discussion; On my formula there is lots of tuning software available since its very common and the programs accurately estimate duty ...
- 05-08-05 02:06 PM #1Cadillac Owners Member
- Join Date
- Mar 2005
injector duty cycle
On my formula there is lots of tuning software available since its very common and the programs accurately estimate duty cycle for you as the car is running but on a caddy like the 4.5 or 4.9, more specifically the '88 4.5, how would you measure the duty cycle of the injectors? I mean if someone were to add a delta cam and do some headwork there are obviously increased fuel needs with the increased rpm's and air so how would you tell if the injectors are reaching thier limits or not? Besides maybe sending them past thier limits and detecting a lean condition on a wideband o2 sensor...
- 05-09-05 12:00 AM #2Cadillac Owners Enthusiast
- Automobile(s): 1995 Sedan De Ville (4.9 L)
- Join Date
- Oct 2003
- Woodridge, Illinois
Re: injector duty cycle
I am not sure about a 1988 4.5L engine, but on my 95 4.9L, the on-board computer tells me the pulse width when you get on the diagnostic mode. If you know the RPM, you can back-calculate the duty cycle, I think. But the pulse width changes a lot depending on your condition, so it would be very difficult to relate it to the cam profile...