FiTech EFI system

aspencade said
I have a question about the timing control many of these EFI kits have. Its not really about Mopar ignition but any ignition be it GM/Ford or Mopar. I keep reading everywhere about how rotor phasing needs to be done when installing one of these kits with timing control and i am kinda baffled. Isn't rotor phasing something that should be done as part of the tuning process even with a carb set up? I understand an adjustable rotor would be needed when using an old carb set up as you would need to set the timing first, lock the distributor down tight then fine tune the rotor phase after timing is set. Why would you need to do all that with one of these Fitech EFI kits? (or any other of the kits out there that have the timing option) Why would you need an adjustable rotor with the Fitech kit? Why not just use a cap with a hole drill out and get your rotor phased perfectly on TDC of #1 and then lock distributor down before you even start the engine up. Won't the Fitech ECU then take control of the timing for you? Am i making any sence or am i just nutts :)

It takes a while to grasp, but you need to think of it in terms that the cam/engine position/distributor shaft is locked together. They move in unison. The distributor rotation adjusts timing, it doesn't "phase" the rotor. the fitech still gives a base timing you need to set your engine to with a timing light (not zero). It takes over timing from there. "bolting down" the distributor with the rotor pointing to #1 (on a stock setup) has done nothing more than actually set your timing to ZERO. Your post is a little confusing because you start out sounding like you are 100% advocating for rotor phasing on all engines, and then by the end you are asking why it's required at all for a fitech.

Think of it like this. You set your timing with a timing light at 14 degrees (distributor location). While The rotor is actually out of phase by 10 degrees (engine position) the 10 degrees of phase isn't evident on a timing light because the spark is still making contact with the terminal.

So your fitech unit now tells the engine you're at low load cruise. Fitech sends 45 degrees of timing to the engine, plus the 10 your rotor is out of phase. On a small cap distributor, you're now dangerously close to the spark jumping to the next terminal.

this is part of the reason I don't recommend reusing anything OE. in most cases the tach signal isn't clear enough for the unit to function, and the old style rotor, and what not, is not mean to be phased.