Dead driver on '165?

[Shannen Durphey]

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
Turn tps up to .7V
> 
> 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.
Does this have a "crank" input?  Should be b+ during cranking.
Here's a VATS bypass found by an inexperienced Ford mechanic.  Pull
the prom and start cranking the dizzy.  Install the prom while
cranking the dizzy.  If VATS is the problem, injectors will start
firing.  Take the info whatever way you'd like, but I saw it done
repeatedly in an attempt to diagnose a no start caused by VATS ign
cylinder.
'Course you could disable VATS in the prom.
Shannen
> 
> 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