Dead driver on '165?

[rr]

I got a weird feeling, try a small fan blowing into the maf. Maybe
without airflow, it won't kick the fuel on?

BobR.

Bob Valentine wrote:

> Here's what I've got, and I'm suspecting either the injector drivers or
> something else is fried in this ECM.  Note that I never actually ran it in
> a car.  I've checked most of the sources for a schematic of the '165 and
> haven't found any.  Is there one?  Again, this is '165 / ABYA (88 350 Camaro)
>
> My "test bench" consists of the ECM, all non-emissions related sensors
> (except for VSS) and all 8 injectors (note I'm using Ford injectors which
> tested ok on my 555 injector cleaner/tester).   I have the dist. hooked to
> a variable speed motor, I've been "cranking" the motor at about 100-300 rpm
> (dist speed) which corrolates to about 200-600 crank rpm.    MAF is hooked
> up, park/neutral line is tied +12, FP is also hooked up.  TPS is set a .5v
>
> On "cranking" the FP comes on and stays on until "cranking" stops.   IAC
> motor can be heard exercising slightly.   The injectors never fire, not
> even once.  Swapped in a noid light, it doesn't come on either.   I have a
> 555 VATS eliminator tied to pin B6, I've tried frequencies ranging from
> about 20 to 40 hz (as determined by my o-scope).   With or without the VATS
> makes no difference in the operation below.
>
> Everything seems fine except for the fact that the injectors don't fire.
> The check-engine light (no scanner / aldl reader yet...) turns off
> momemtarily while cranking, then comes back on.    ECM is setting a code
> 34;  low MAF reading. This is to be expected since there's no airflow....
> ;^>  I've checked for power at all sensors and the MAF - it's there and good.
>
> The only other thing is that the main heatsink in the ECM gets fairly warm
> after about 10-15 minutes of power applied.   Is this normal?
>
> So are the injector drivers bad, or is there still something with the VATS?
>
> --> Bob Valentine
> --> bob at tecmark.com