No spark from the ignitor pack, schematics needed

Hi,

If you have no spark, are you sure the crankshaft position sensor isn't bad? Do you have an RPM signal when cranking the engine?

As far as the coils are concerned, they receive 12v from fuse 9 in the under-hood fuse box. However, the fuse has no power until the powertrain relay powers it. So, you may want to first check fuse 9, and confirm there is power to and from it. If there isn't, check the relay.

Next, the power from fuse 9 is present at the coil pack. For a specific coil to fire, a ground path is provided by the PCM. Once the ground path is provided, the circuit is complete, and the coil does its job.

I attached the entire powertrain management schematic below. The schematics were 4 pages long, but I had to cut each one in half to make it readable for you. I did overlap them.

If you do have a live data scan tool, see if there is an RPM signal first. If there isn't, suspect a faulty crankshaft position sensor.

Take care and let me know what you find.

Joe

See pics below. Note: I highlighted the relevant wiring for the ignition coils.

Hi Joe,

I want to thank you for your quick response but mostly for your remarkable advice. You have provided me with excellent and crucial information. To Be honest I never expected the kind of response I received. The amount of useful and detailed information you gave will help me a great deal if not outright solve the problem. I had only been expecting (if I was lucky) to receive the appropriate schematics and without the detail you included.

However, I can't use this wealth of information right away. I thought I would be studying the diagrams and would then take what I had learned from them to then further diagnose the problem.

My delay is that I have the car in the garage of a house of a friend of mine whose daughter lives there. That was to keep it out of the Winter elements. But for whatever reason her daughter doesn't want me to work on it there stating she is concerned that her young daughter will somehow get hurt. I don't really get it but...

Anyway, I’ve caught up with the other projects I’ve been working on, and my focus is now back to the Chevy. The remaining issue is the complex I live in doesn’t allow any work on tenants’ vehicles. So, I am currently looking for a garage or other place to rent where I can continue to work on it. So, unfortunately, this won't be tomorrow but hopefully very soon.

As soon as I get the Chevy moved to a place where I can work on it, I would like to let you know the results after following the direction you've given me. Or if I'm still stuck with a bit of further information
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What I would like to know is if this site I am using now is how I might reach you?

Again, thank you for the terrific help you've given me already.

Rick

Hi Rick, first you are very welcome. And certainly, you can reach me via this site and thread. If you start a new post, I may or may not get it, so just add to this one.

Let me know what I can do to help.

Take care,

Joe