No CEL or scanner communication

[Cameano at aol.com]

Hi, all,  my name is Darren Pferdehirt, I'm new to the list, although I was 
subscribed about a year ago for a couple of months.  I've come back seeking 
some help with a friend's car.  It's an 89 Pontiac Firebird, 2.8l PFI, manual 
trans, a/c car.  The car was running fine until this last Sunday.  It was 
shut off, and a couple of hours later, when he went to restart it, it 
wouldn't start.  I took a look at it, and determined that it wasn't getting 
any fuel.  So I went to hook up my Snap-On MT2500 scanner, but when I hook 
up, and turn on the key, it won't communicate with the ecm.  Also, there is 
no Check Engine Light, but I've pulled the dash and verified that the light 
is in fact good.  

Not having a good reference manual on this car, I went to Alldatadiy.com and 
subscribed for this car.  From the info I've gotten off the site, the only 
problem I can find is the ckt 340 (fuel pump oil pressure switch) is open.  
Tracing the circuit, I see that it leads back around to the fuel pump signal 
terminal on the ecm.  Is this a good indication that the ecm all of a sudden 
just took a dump?  One note, when I had the scanner hooked up the first 
couple of times, the car would start, but it was in "limp home mode", very 
rich, poor running.  As soon as I would unhook the scanner from the aldl, it 
would die, due to the fuel pump shutting down.  Now, it won't even to this.  

I do have another ecm from an 85 Firebird, with the 2.8 PFI, but auto trans.  
I've tried swapping ecms with the same results, also swapping PROMs between 
ecms and trying both, with the same results.  

Anyone have any suggestions?  I'm at a loss here.

Thanks in advance, 

Darren Pferdehirt
Waipahu, HI