At 03:14 PM 4/13/2010, pdooley wrote:
>David remarked of higher solder joint failure rates for hot components.
>The injector drivers run relatively hot.

It's not so much the heat as the thermal cycling.  This is aggravated
because the voltage regulators and drive transistors are solidly
mounted to the heat sink, so the cycling tends to yank their legs out
of the board.

>Could we assume the injector drivers are not getting enough current to open
>the injector solenoids due to faulty solder joints limiting current flow?
>Noid light only shows the signal, not the strength, as Mark pointed out.

No.  But it's not at all unlikely, and those large joints are the
easiest to work on.  Be sure to use at least a little fresh 60/40 or
63/37 solder.  It's not a bad idea to use a solder-sucker to remove a
good bit of the existing solder first; but not usually necessary.

>If so, don't bother with a spare ECU, just carry a butane powered soldering
>iron:)

And some fine rosin-core solder, liquid rosin flux if available which
it probably won't be otherwise electronic flux in grease (Radio
Shack), solder-sucker, solder braid, fine tip for the iron, soldering
sponge, strong light, strong magnifying glass or stereo microscope,
little fan to carry the flux fumes away from your breathing
zone...there are a lot of joints in there, and most of them a lot
smaller than the big holes for the transistor leads. ;-)

Do Not Ever Ever Ever use plumbing flux on electronic gear.  Just Don't.

Yours,
d