gmc sonoma 1997, no power on fuel pump?

[elkizzy]

truck was driving fine, but yesterday i tried to start up the engine, and wont start, so i drop gasoline in the carburator, it works for acouple seconds and die again, i check fuel pressure and has none, i installed a new pump, but does work, pump does not make noise, i replaced relay and fuse, still same problem, i test the power on pump, when i turn the ignition on shows only 5.7 volts for about 3 seconds, and then 0 volts, i installed direct ground prior to the pump plug and the motor start right up, but after 6 or 8 seconds die again, and then i turn the ignition switch on and start quick but dies after 6 seconds (if desconnect the by pass ground, do not even turn on for a second)

 

[Molson02536]

truck was driving fine, but yesterday i tried to start up the engine, and wont start, so i drop gasoline in the carburator, it works for acouple seconds and die again, i check fuel pressure and has none, i installed a new pump, but does work, pump does not make noise, i replaced relay and fuse, still same problem, i test the power on pump, when i turn the ignition on shows only 5.7 volts for about 3 seconds, and then 0 volts, i installed direct ground prior to the pump plug and the motor start right up, but after 6 or 8 seconds die again, and then i turn the ignition switch on and start quick but dies after 6 seconds (if desconnect the by pass ground, do not even turn on for a second)

I would say you need to look real close a couple of things one being check all fuses I have had a few where the ignition switch(electrical side) was at fault and not sending power out to where it is needed but most common that has disabled spark and fuel at same time is theft deterrent and only way to check this correctly is with a scan tool from the dealership

The PasslockTM system is designed in order to prevent vehicle operation if the current ignition key is not used in order to start the vehicle. The ignition key will allow the lock cylinder to turn. Once the lock cylinder turns, the PasslockTM sensor (located inside the ignition switch assembly), sends an analog voltage code to the body control module (BCM). If the BCM receives the correct analog voltage code from the PasslockTM sensor, the BCM sends a Class 2 message to the powertrain control module (PCM)/vehicle control module (VCM). The PCM/VCM then enables fuel delivery.

The body control module (BCM) supplies the following items to the Passlock sensor:
A 12 volt supply voltage
A data line
A ground circuit

You must diagnose the diagnostic trouble codes in the order specified in the PasslockTM system diagnostic trouble code list. Failure to do so may result in the following conditions:
Extended diagnostic time
Incorrect diagnosis
Incorrect parts replacement

My best guess would be to replace the passlock sensor it is made in the ignition cylinder housing after replacing do this relearn for theft.

1. Ensure that the battery is fully charged.
2. Use a scan tool in order to clear the PasslockTM DTCs.
3. Turn the ignition switch from the OFF position to the CRANK position, and then to the RUN position.

The vehicle will start and then stall.
4. Leave the ignition ON until the security telltale turns OFF in 10 minutes.
5. Repeat Steps 3-5 for 2 more times (3 times total)
6. The PasslockTM controller will learn the new data on the next start attempt.
7. Use a scan tool in order to clear all DTCs.

Here is a link to your wiring code to your for your ignition system.
http://gsi.xw.gm.com/image_en_us/gif/000/000/395/395753.gif