My apologies if this belonged in the DFI/ECM section... it's TBI Injector related.

Well this issue has gotten out of hand. Only one of two TBI Injectors fire under certain conditions. When the ECM is moved or adjusted the issue goes away (Loss of power while driving, tap the under dash pad where the ECM is and boom back to normal). Narrowed it down ckt 468 (green wire that splits between pins C15/D14) that controls injector # 2. Don't know if I should approach from the connector end and "re-seating" those pins or tracing backwards searching for a break in the wire.

Both approaches seem very, VERY challenging...

 

Let's be careful of terminology. Sounds like your injectors have POWER just like they should.

What they don't have is a consistent GROUND at the ECM for #2.

Whether you have a broken wire that has intermittent contact, a molded-connector pin that's out-of-position, or some internal fault in the ECM is yet to be determined.

Wild Guess: It'll be fairly apparent as soon as you expose the wire harness at/near the ECM.

 

I've had the ECM down, swapped ECM's, looked over the connector along with the 6in of wire from the connector back and nothing really stood out. No wires were noticeably loose, I'm at a loss. Any hints on where you'd start the troubleshooting?

 

I'd have expected a wire or connector fault near the ECM, as smacking the dash restores operation. Doesn't seem to me like it could be anything under the hood; or "far away" from where you're slapping the dash.

Wires broken inside the insulation? Used to be common on GM HEI pickup coils.
"Loose" terminals on the ends of the wire or in the plastic connector on the ECM? Intermittent contact?
Two faulty ECMs, both having failed the same way? Seems really unlikely.

That's all I got. Good luck, and "happy hunting".

 

Have you looked at c207 ?

 

 

Wouldn't c207 kill both injectors at the same time?

 

G and b two different power wires

 

So on the G side that would be from the fuse block back to C100 all the way through the harness up to the injector I assume, where as I always wack the passenger side dash underside cover and it's back to normal. Heck I even drove with it rested on the floor for smooth operation... that is till it slid and boom issue returned. If I'm reading that right it's D14 that actually controls the injector correct?

 

Power from the fuse box to c207 to the injectors .
C207 is next to the ecm could have a bad connection.

 

 

Forgive my stupidity however those look like the actual connectors for the ECM... Didn't see anything like it next to the ECM.

 

Iirc it’s a clear plastic connector

 

This is what I have, If c207 is that offshoot, it was covered by that foam. If that's it... how do you suggest I check it?

 

Looks like the wires you need to look red and white.
table apart the connector and look at the terminals. Or run the car and wiggle the wires.
if failure occurs the engine will run rough.

 

Ran the car, wiggled, jiggled, moved and grooved the ECM, harnesses, and suspected wires... Issue didn't happen. This is going to be one of those hope it happens as I'm pulling up at home to catch it in the act situations. That is unless you can see individual injector status in TunerPro...

Also, would troubleshooting change if it only happens while driving? If so, any suggestions?