I finally got things squared away and was ready to start the SS. Which quickly ruined my day because the car wouldn't start. I am using the Super Aujp V2 bin with VATs disabled, cyl vol set to 834, and inj. constant set to 30 (for 30 lb injectors). I am burning proms the old school way by using a zif socket on the 730 memcal. I get the SES blink with the key turned to on. I also get a code 12 when A and B are jumpered together. I am using a custom harness which I got from the nice guy at Chevy Thunder.com. I've also used his troubleshooting pages and verified I have the correct voltage/ground signal on each ECM pin. I have spark which was verified by pulling a plug and laying it on the engine while cranking. It seems like I have fuel because there is a light smell/mist of gas on the plugs after cranking for a little bit. The fuel pump primes when the key is first turned. I have an old laptop that I was running ECM852 on to try to log something. I have attached that file. A few things jump out at me. One the engine RPM never changes from 0 even though I tried starting the car a few times. Also the battery voltage seems low at 11.9 and then takes a major dip when I try to start. This must be measuring the voltage at the fuel pump wire. That seems to measure wire measures 11.9 while my battery is measuring 12.8. The ECM battery power wire measures 12.5 and dips to 10.6 while cranking. You can tell when I try to start the car in the log by the battery voltage that drops to about 4 volts. Can anybody shed some light on what the problem is? The file is a tab delimited text file.

 

the fuel pump & ECM voltages are measured at 2 different terminals at the ECM.
your getting a major voltage drop to the ECM. it will never start with 4 volts to the ECM.
make sure your battery is good & then try this, run a hot wire from battery positive to the injector fuse box & see how much voltage drop your getting.

 

I measured the ECM voltage at Pin C16 during cranking this voltage was dropping to 10.5 volts. However I suspect the fuel pump voltage was dropping to the 4 volts. This harness has two connections for connections that need power in run and start I tapped both wires into the ignition feed at the steering column. Was that a bad choice? What is the injector fuse box? Do you mean the injector pins on the ECM? Here is the harness I am using.

http://www.chevythunder.com/speed%203.jpg

I am not using any emissions equipment. The two wires at the top labeled ignition power connectors are tapped into the large pink wire coming from the steering column that used to go to the large cap HEI. Now it powers the small cap HEI with remote coil.

Also shouldn't I be seeing RPM during a cranking situation? The distributor is new.

 

i thought your harness may have been like the factory harness which has a fuse box for the injector fuses & 2 other fuses in it.

i used a factory harness on my car, i sometimes have problems starting it. its caused by low voltage to my ECM. if my ECM sees less than about 10 volts during cranking, it won't start. when it won't start, i can put battery power to the ECM fuse box & it will start after extended cranking. i believe the motor floods out some with the low voltage.
10.5 volts should be enough for the ECM to work.

im pretty sure you should have a RPM reading during cranking. not having it can be caused by power or ground problems to the ECM. if i remember right, when my car won't start i don't see cranking RPM.

i see a total of 3 power wires on your harness, 1 is the main power which i think should be hooked up to battery power. the other 2 for switched power. if your getting good power to all 3 during cranking, check the grounds. make sure you a good battery to body, battery to motor & motor to body grounds.
also, you may want to try putting power from the battery to the 2 switched leads & see what happens.

i looked at your log, its kind of hard for me to read, how old is your laptop? what version of windows do you have on it? if you have 98, you should be able to use TunerPro.

 

I'm thinking the switched wires are seeing a voltage drop. I'll have to check those wires while cranking. I've checked the ground pins on the ECM and they seem to work. Possibly the ground may not be making a perfect connection but they seem to work. The harness is grounded to the firewall. I sanded away some paint and used a sheet metal capscrew. I have the negative battery cable bolted to the pass. cylinder head. There is a 12 gauge wire going to the passenger fender straight from the negative cable. I also have a ground at the back of the motor to the fire wall on the pass. and driver side. I might pickup new ground cables just to ruke that out though. This was how things were grounded with the CCC system. I'll try to give the switched wires a direct feed to the battery + to see what happens. The log was originally a CSV file but I had to change it to a tab delimited text file to attach to the board. If you open it in excel and select tab delimited it will display fine. The laptop is like a 120 mhz running Win95. It was free so I'll have to stick with it for now.