Alright, TPS is fine vats does prevent cranking when blocking the chip, ECM throws no new codes when provoked. Running out of ideas here.

 

grab a paperclip and short a+b

does fan come on?

lets see if your ecu is controlling the fan.

 

Yep fan comes on

 

A couple more things I discovered. The passenger side injector bank was receiving 3 volts on the ground side with the ECM disconnected and the key in the run position. There was a small short in the injector harness just off of the firewall. Fixed that. No dice.

Next, the distributor looks new. I don't know if the previous owner replaced it in an attempt to fix the car, but I was wondering if it is possible to test the signal of the purple-white distributor reference wire.

I did verify the reference wire is connected between the ecm harness and the distributor harness, just don't know if its actually referencing.

But I'm starting to think ECM since its fails to throw trouble codes.

Also, the dash will illuminate, but information will appear at all. Nothing. Not sure if this could be related. Need to check the polarizer.

 

did you disconnect the electronic spark control single pin connector and try to crank the engine? and still no codes?

 

I did.

It turned the fan on high, but did not throw any codes besides code 12.

 

Would I be correct to assume that the ecm is receiving distributor pulses if the fuel pump runs while cranking?

 

Did u disconnect this and try to start it to see if it throws the code?

 

See post #26

 

test the ignition control module:

https://www.corvetteforum.com/forums...post1594459481

 

Good news, it runs!

I'm not certain what actually fixed it since I did several things in between starting attempts:

The first thing I did was verify some things on the ignition side of the car. I discovered that the firing order was correct, but at tdc on compression stroke, the rotor was pointed toward cylinder #2 instead of #1.
Next, I removed and inspected the icm. The thermal compound was still tacky and present. The dist reference wire connector was slightly corroded, so I cleaned it up.
While the icm was out, I tested to see if the computer was recognizing the reference pulses. Using the +5v source from the TPS wire, I tapped the reference pulse wire with the ignition on. This fired a series of relays and triggered the fuel pump, so the ecm is obviously understanding the reference pulse and trying to start the car. (I should've tried the noid light while doing this, but I didn't)

I put everything back together and rechecked the fuse box. Some of the fuses, especially the inj and ecm fuses were really loose in their spots. I got a pair of pliers and put slight bends in the tabs of the fuses to make them fit snug.

Finally, I connected a jumper wire to the grounds of the injectors so I could manually fire them just by grounding the jumper. Cranked the engine while firing the injectors and it sputtered to life, but when I stopped grounding the injectors, it stayed running... Hooray!

When I actually got to hear it run, that's when I noticed the intake runners were on the wrong sides. How is that even possible???? On both sides, there is massive vacuum leaks at the runners. I cannot believe the engine ran like this.
They leak so much air that opening the throttle does nothing... There is so little vacuum.
But while it was running, I used my timing light and set to 6 degrees of timing then shut it down. I'm going to put the plenum runners on the correct side today then update with the results.

 

So how is it running now?

 

Not great.

Intake is installed properly, and all the vacuum lines are repaired/replaced. That made it idle great. It would NOT take throttle. It completely refused to rev up... No codes.
The next day, injector pulse is gone again. Hasn't ran by itself since.
I can make it run by grounding the injectors myself, but the car just won't take over. Injector pulse is gone again. The ecm won't throw codes, it refuses to change outputs based on inputs, the radiator fan will randomly come on/off, and unplugging the tps or maf has no effect.
In diagnostic mode, the service engine light will only show code 12. Sometimes it won't even do that... It will just stay illuminated.

I have an ECM ordered, so I hope that will be the solution to all my problems.

 

ECM fixed it.

Cheers

 

beautiful. Are you going to send your original one out for repair?


and bonus question, when are you entering in your first autocross or Track day?

 

Probably not. It's already a reman.