EMI Problems?

[rr]

Injectors are noisy by default. Whenever the power to a solenoid is
cut, a reverse spike is created. The ecm has zener diodes to suppress
this spike.

Problem is, is that the spike still gets radiated through the harness
on it's way to the ecm.

The fix is to put a diode at each injector. This is along the lines
of the diode found at the A/C compressor clutch wires.

BobR.

JTesta1966 at aol.com wrote:

> In a message dated 11/24/99 7:56:36 AM Eastern Standard Time, kojab at ar.com.au
> writes:
>
> << I have a strange feeling that many problems on high load/high rpm may be
>  caused by EMI produced by the spark lead or ignition modules. A friend
>  of mine had such a problem and moved his coil pack around the car, with
>  suprising results. The car basic >>
>
>  Ya know, its been drawn to my attention a few times, by a WELL versed tuner
> that some injectors cause this problem too. Matter of fact, the injectors I
> have (MSD50's..aka..Rochester) apparently cause lots of electrical "noise" in
> my pals car while he was usinga batch fire DFI, when he switched to a SEFI
> box the problems all but went away. (I think I'm relaying this right, it was
> a long time ago) Anyway, he attributed it to 6 "noisey" injectors at the same
> time wreaking havoc on his electronics. And when he went to a SEFI box the
> problem was just about eliminated I assume since there was only one injector
> acting at a time. He said some injectors were more suseptible to this noise
> than others. He said the MSD's were the worst...now he tells me ;-P So, my
> point I guess, noise can come from MANY places. Not only ignition components
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Jim Testa                                         TType86 on #BuickGN
> jtesta1966 at aol.com                                   irc.dal.net:7000
> ASE Master Technician        NJ Lic. Motor Vehicle Inspector