[sierrap615]

Originally Posted by madpogue

Well, being in IT, I know how "universal" these standards are (NOT). I thought OBDII had some "space" for make/model-specific codes. What about codes that are specific to equipment? To me, throwing a campos code on a car without one makes about as much sense as throwing a code related to an auto tranny on a car with a manual.

there is a "extra space" all the codes are five digit right? the second digit is ether a 0, 1, or 2. 0 is standard, and 1 is specific, how ever the 0 and 1 code then to be simular IMO. i have no clue want the 2 is for but i think it a communaction problem.

but you must also remember the cam signal is produced by the IGN module, the PCM doesn't have a clue that there is no cam sensor ether, in the computer's mind it looks like a cam sensor, it acts like a cam sensor, so its a cam sensor.

Originally Posted by madpogue

Actually, I think it's 1-4 and 2-3, but I get the picture. And "cheaper" in this case only applies to initial design and manufacture, not to long-term maintenance (surprised?).

Yeah, the "waste" firing is self-evident, and I kinda guessed that it meant the cam position is a non-issue. Still seems like a crude approach to me.

yea its 1-4/2-3, the waste spark system does seem crude at first but compared to a distributor its a piece of art. but it is also cheaper in the longterm, there are no moving/mechanital parts in the DIS system, no timing, points or dwell to adjust, its all done by the computer. also you have better control of timing theirfore better fuel mileage, better emissions, and better power, dispite fuel grade or atmosperic condistions. plus you can have traction control and knock retard(distributors can, but its not as easy) you don't need to replace the cap and rotor. and the plugs don't wear twice as fast. think of it this way, if you have a 0.040 gap with a 10:1 compression ratio, at TDC compression that 0.040 gap is now more like a 0.400 gap. but since on exhaust stroke there is no compression that 0.040 gap acts like a 0.040 gap, using a minimal amount of power compaired to its companion.

Originally Posted by madpogue

This is what's meant by "sequential" fuel injection, right? So yeah, can anyone enlighten us as to whether this is the case with S-cars?

91-95 - OBD1 - no cam signal, all fuel injectiors fire at the same time
96-02 - OBD2 - with cam signal, injectiors fire in order, this is sequential

the cam signal can also be used with the knock sensor to determine which cylinder has a misfire.