1986 2.5L to 3.4L: Amateur Hour

[coheed]

Make sure whatever you're using to bypass the VATS is sending the correct signal and that the PCM is seeing it. If you don't have scan9495 on a computer and an ALDL cable, I would get one. Scan9495 will show if the PCM is throwing a code for the VATS, and it's easier to use than most modern code scanners in my opinion. I had 2 different bypass modules hooked up to mine, and for whatever reason the PCM wouldn't recognize the 55Hz signal that was coming out of the bypass modules. And without that the injectors won't fire. Noid lights would also tell you pretty quick if its VATS not pulsing the injectors. Eventually I spent the money on Tunercats and disabled VATS completely in the PCM, along with editing some other things.

[FigurativeGarbage]

Thanks, Coheed. Yes, the noid flashes a bit. Yesterday I found that my PCM ground wires (C1 and C17) were not connected. I got one hiccup. I can still test voltage levels at cranking. I have suspected VATS (by Timers) could be the issue. I recall you ground it to change the Hz, and I am using the default setting. Agree I should get a scanner.

[FigurativeGarbage]

Reviewing my notes, the PCM I ordered years ago was actually for a 94-95 automatic, not a manual. Unclear if that matters, as I gave the seller a manual Camaro VIN for coding.

I had the Timers VATS bypass set to 30Hz. I set it to the more common 50Hz. Still nothing. I can try the two other functions on that system, but your comment makes me doubtful it will help. On your suggestion, I've downloaded the Scan9495. I ordered a jumperless ALDL connection and matching wire mount, but it take a week or so for them to ship. Once I see what's happening, I'll see if I need to escalate to deleting the VATS or otherwise tuning.