Hi, I'm pretty new to third gen but I have a random question about an engine swap and ecm, it will prolly come off as stupid but I seriously don't understand electrical stuff at all. So here goes

I have a 1991 camaro RS with the stock 305 V8, I am currently having starting issues, all power, no crank. I've narrowed it down to something in the vats line. I've done the bypass trick, replaced everything apart from the actual vats module... Yah.
So my question is I plan on putting in a 350, not sure if I won't to go carbed or TPI, is it possible to take an ecm out of an older camaro without vats, say 88 and before and plug that in and it start up because those cars didnt have vats at all. I guess I'm just confused on what ecm to go with if I put in a new motor, I know I need a 350 ecm, but does it have to be from a camaro, or just any old 350 ecm?

 

The VATS module controls the starter enable relay, the fuel enable relay, and the inst. panel light. The ECM gets a signal from the fuel enable circuit, allowing it to enable and control the injector pulse width. It may be your VATS module if you have bypassed the VATS resistor by installing one in-line. Make sure you measured the correct resistance, without touching it of course, and that the one installed is correct.

You can replace the ECM, but it won't do much. Even if you can get it to run without the necessary VATS signal for the fuel enable circuit, i.e. changing the necessary values in your PROM IIRC, it still requires the starter enable relay which the ECM can't control. You can bypass this if you want (there should be threads on this site about that).