[Diy_efi] RE: Diy_efi Digest, Vol 21, Issue 1

[ScottyGrover at aol.com]

In a message dated 11/3/2006 10:29:27 A.M. Pacific Standard Time,  
espresso_doppio at yahoo.com writes:

---  terence difalco <olpaint at hotmail.com> wrote:

> a ford white  (Escort 1.9L) which matches specs quite
> closely but I have two  questions. First the jag
> specs say peak and hold and the escort is I  believe 
> saturated. Is that about the ECU or the  injectors?

Both.  Saturated-drive injectors are high  impedance;
peak-and-hold are low impedance.  Peak-and-hold
injector  drivers are quite different from saturated
drivers.  If you connect  high-impedance injectors to a
peak-and-hold driver, it will operate  in
saturated-drive mode.  P&H driver ciruitry generates a
lot  more heat than sat. drive, and requires more
expensive components, which is  why OEMs tend to avoid
it when possible.

> Second, can I exchange  the tops of similar bosch
> injectors without destroying the inner  workings.

I have not had cause to disassemble injectors, but I
think  there is probably a reason why certain shops
charge a decent amount of  making custom injectors out
of parts from various different ones; I don't  think it
is trivial to disassemble and rebuild injectors. 
Someone with  more experience in the matter should
weigh in on that issue,  though.




Peak-and-hold injectors (at least the ones I have had dealings with) ran in  
series electrically with resistors which increased the resistance and lowered  
the required current in the circuit so as not to increase the drain on the 
power  transistors in the control box.
Scotty