Okay, ECU = Engine Control Unit, which may control both fuel and ignition. But, many older cars had separate computers for fuel (e.g., EFI controller) and ignition (e.g., ICU or knock controller or electronic rev limiter). Thus, when attempting to upgrade an older system with separate computers, what does the rule permit as far as using a single computer in place of two? Recall that we were allowed to add ICUs even before the new ECU rule, as long as they used the stock spark distribution method (e.g., distributor if there was one). Any reason why the added ICU can't reside inside the stock EFI controller housing along with the fuel control (that is, besides fitment/size issues)?
Very pertinent rules:
17.1.4.D.1.e -- ignition
17.1.4.D.1.a.6 -- ECU
17.1.4.D.1.s -- ECU
Other possibly related rules:
17.1.4.D.9.c -- gauges (sensors?)
17.1.4.D.9.j -- radios (wiring alternative?)
17.1.4.D.1.b -- fuel pumps/lines (injectors?)
17.1.4.D.1.a -- jets (injectors?)
17.1.4.D.1.c -- MAF penalty
[This message has been edited by Eric Parham (edited March 17, 2004).]