Ok. Brand new here...also 1st time using forum.
I have been working on cars for about 25 years and have lots of experience but also always learning new things.
anyway I have a 91 Camaro with the 305tbi and t5 manual. It ran but smoked and decided tip pull the 305 and go 350...I deleted the smog system and not using a/c currently....but neither of those should stop the car from cranking...I have ignition power, I've checked my key with ohmmeter at key and matched ohms at vats wire under dash. I can crank but powering the purple wire directly at starter but you can see no fuel injecting into throttle body...I'm assuming my vats has something to do with it or the vats module is faulty. I have tested 12volts from yellow wire coming from the harness just above the steering column but nothing from the tan and yellow wire that goes to the clutch safety switch Also again assuming that its vats shutting it down.
it did run fine before pulling engine and has not been under 12v power for nearly 4 months...could the vats need a hard reset or maybe it just died? Any thoughts.

 

Is you security light on?
Will it try to start with starting fluid? AKA do you have spark. Do you have fuel pressure? Lastly is there signal to the injector. (only test with the correct noid. If you volt meter draws to much power it can fry the quad driver in the ECM.
Having a fuel pump die would be a lot more common from sitting then a Vats system.

 

No security light but never has lit up I think bulb may be bad
There was fuel pressure cause pump turned on...had spark when I manually cranked it, but no fuel sprayed while cranking...
I pulled ecm and pulled ecm from my 91 chevy 1500 and plugs were identical...
Put truck ecm in and car fired right up and ran
My key is bouncing around narrowly at 9.13-9.2 ohms. Minimum is about that. I think that my chip in key is just wore...was told that resistor can fail if it sits in the ignition for to long.
my choice as of now get another ecm from the yard or try electric shop for new resister

 

Clean key contacts of resistor, or, get a 0-10K rheostat and place leads with the two thin white wires going to VATS module and dial in resistance of key.
Or, replace key socket in steering column. You will need ownership proof of Camaro at dealership, they still sell the socket.

Did Camaro ECM work in truck?

 

Contacts can't get any cleaner lol... and I tested resistance at thre wires underneath and had same as key. So ignition tumbler is good... the universal vats dialer I found was way more than another ecm from scrap yard. I know the ecm from Camaro won't work in truck cause prom is programmed to march vats reading
right now cheapest way to go is 25 for the ecm from scrap yard or about 15 from electronics shop for resistor in the middle of what my vats needs.

 

So I ordered the 15 resistors that are used in the vats security. I put the one mine requires into vats wire and I still get no start. This is absolutely beyond frustrating. I used my 91 chevy truck ecm before and it worked Literally ran Heard it with my own ears. Attached exhaust and put water in. Got a few things buttoned up. Went to start and stalled almost immediately then wouldn't start back up again. checked fuses, unplugged ecm put in truck and truck started and ran fine ...put old ecm (from Camaro) with new resister and still nothing...tried ecm again from truck Still nothing. I'm really wanting to stick a grenade into it and make the creator of vats security eat rotten eggs. this is ridiculous...

 

Another troubling tip VATS tip:
Attempt to start with key, original.
No start, as in no crank, turn off IGN and remove key.
Wait approx. 3 minutes and re-attempt start with same key.
If engine starts, bad VATS socket for key.
If no crank, then another problem.

 

Under dash power distribution box (under driver side kick panel) is burned out. Need to replace it. This box distributes power to the ignition switch, dash lights, starter relay, etc. PAIN IN THE ***

TO GET TOO.

 

I have a 1990 camaro rs 350 tbi, with a no crank No start issue, I replaced starter, battery, alternator, starter relay, ignition switch block, checked all fuses and no lights on dash cluster and still nothing! I also bypassed VATS with resistors!

 

GM did not build a 350 tbi for the camaro. GM put a 350 TPI L98 350 in the Z28s. The only V8 TBI Camaro was a 305. I only point this out because if the motor has been swapped then the potential of odd ball issues goes up dramatically.

Power to the starter comes out of the ignition switch through the neutral safety switch to the starter. There is a fuse as some point also. It as been a while but I do not think it has anything to do with the computers. Yes the engine will not start with VATs or even ECM issues but it should still crank and try to start.

If you grab a manual it should give you a step by step. Could very well just be a wire or a connector. To find it you will need to back track the power. Example: Are you getting power to the small wire on the started? if so are you getting in and out of the neutral safety switch. Next would be the fuse then to the ignition switch. On older cars you are better off just replacing the single wire. If you start digging into the harness you can cause more damage then you fix. Trust me you start moving a 30 year old wiring harness around and the repairs required will seem never ending.

You can by past the neutral safety switch or even start the car with a remote starter.