95 blazer no injector pulse

[abchevy1]

Ive got a 1995 chevy blazer good fuel pressure, good spark, But no Injector pulse. Any Ideas would be great.
Thanks Jon

[rhandwor]

Check first if the security system has shut off power. Use a DVOM and check if you have power to the injector. The computer pulses the ground this is what fires the injector. Check the harness for a break or disconnect.
http://www.alldata.com/ has good wiring diagrams. Cost appx. $29.95 for a years subscription.

[abchevy1]

Sorry I forgot to say I do Have 12v, the injector driver is not commanding the ground Even at the vcm I belive all inputs look good how ever something must be missing.

[rhandwor]

If you have a chip {resister} in the key try another key. I think the security system is shutting you down a common problem. If this is the case you probably need a new key switch or to sweat a resister in the line and relearn the BCM. Is the security light blinking or does it start and then quit.
If no security system ohm the injector ground wires from the computer. If they are all satisfactory you may need a new computer. You need to look at the wiring diagram but you can always try a scrap yard computer.

[abchevy1]

I believe this vehicle does not have a security system its had a vcm and injector wires check good its got to be an input to the vcm commanding no pulse to the injector

[rhandwor]

I would suggest a wiring diagram. http://www.alldata.com/ Cost is appx. $29.95 per year. They have good wiring diagrams. Check all power feeds to the computer. Check all grounds for the system. The computer has more than one ground. These wiring diagrams show all grounds.

[tempfixit]

What is your fuel pressure?

[abchevy1]

fuel pressure is fine 60 psi I have no injector pulse and all inputs to the pcm/vcm look good

[rhandwor]

How did you check your computer. If a crankshaft position or camshaft position sensor went bad you wouldn't have good spark. Did you ohm the wires from the computer to the injector. Did you touch from the wire to the frame to be sure they aren't grounded.

[old_master]

The pink wire at the injector should show battery voltage when the ignition is in the START and RUN positions, (comes from ECM/IGN fuse #10 20 amp). The dark blue wire at the injector should be pulsing ground while cranking, (comes from connector "A" terminal 16 of the VCM). Does this "check out" on your vehicle?