Hello,

This is in pursuit of my lingering and mysterious P0304 investigation. I've search here and there to no avail.

It has been suggested that I check continuity of the circuit that supplies injector for Cyl # 4. Which wires from the ecm supply such? and adjacent cylinders? (to insure my multimeter readings are not a fluke... my multimeter is not a Fluke; therefore my numbers given may be!)

Thanks!

Joey

 

I dunno if my computer uploaded the file correctly.... if the injector schematics don't show up here, send me a private message with your email and I can send em to ya that way.

 

Don't forget.... All of the injectors are supplied voltage when the ignition is in the start and run positions. The PCM supplies ground to fire each injector sequentially with the firing order, (they are NOT batch fired).

 

It might be a "duh" point to bring up, but just to be sure ya know.... The injector circuits are of the ground (negative) actuated type. If I remember correctly, a continuity check can give a false good reading if you clip directly to ground and put the other upstream from the signal latch. It can also give a false BAD reading if you're doing a simple static test instead of watching for the signal current.

 

What have you already done to diagnose the problem?

 

Thanks FTJ! I got the upload fine, and that's what I've been looking for!

Joey

 

Captain,

The link to the P0304 post is below...it's long.

In summary, I've checked most things for this, at least once, with the amateur tools that I have.

I'm leaning towards changing the entire distributor as I got a day on no P0304 with a C clamp on the distributor.

Thanks!

https://blazerforum.com/forum/2nd-ge...ttempts-85473/

 

Here's a link to the flow chart, it applies to all cylinders: https://blazerforum.com/forum/diagno...4-5-6-a-35153/