Update on P 101

[Ludis Langens]

Bruce Plecan <nacelp at bright.net> wrote:
> In reference to the post Sat, about TBI using 1-5, and TPI using
> 2-10 on the injector timing.  Does any one see any fatal flaws
> about, building a circuit to convert one from the other.  ie:
>
> Using a TPI computer, and measuring it's pulse (don't ask it to
> say aaaah), and then divide by 2, and fire it twice as often.
>
> Then on a TBI doubling it's pulse lenght, and firing it half as often.

It doesn't work that way.

In batch PFI/TPI (at least for 1226870), hardware in the ECM divides the
distributor reference pulses by 2 (L4), 3 (V6), or 4 (V8).  The injector
firing is triggered by this divided signal.  The result is one firing
per cam revolution, aka two firings per intake valve opening.

In TBI (1226864 and probably 1227747 et al), the injector(s) are fired
once per distributor reference pulse, possibly with a time skew.

So, a TBI V8 fires it's injector(s) four times as often as a TPI V8. 
The TBI method ought to work with TPI, except that at high RPM, the
injector pulse rate may be too fast.

There's also the 160 Hz async fuel dribling, and the "only every other
injector event" stuff that will totally screw up your pulse width
measuring.

> It seems the Ford guys have no interest to help with this, so unless
> things change, I don't see doing that box.  The interest for the
> foreign crowd haven't said much, so unless there is demand for
> doing them, I don't see putting the effort into that either.  If they
> do have a "want" the above selection still would cover them.

Lately, diy_efi seems to be diy_gmefi.

               unsigned long BinToBCD(unsigned long i) {unsigned long t;
Ludis Langens     return i ? (t = BinToBCD(i >> 1), (t << 1) + (i & 1) + 
ludis at cruzers.com            (t + 858993459 >> 2 & 572662306) * 3) : 0;}