I`m working on a 1952 Studebaker truck with a 1990 Firebird Formula drive-train. I downloaded a wiring diagram and went to work, hooked everything
up and Bought a VATS bypass module online. I turned the switch
everything lights up but my injectors will NOT OPEN. I tested each banks
power lead, they have power. While turning it over I checked to see if the ECM is grounding the circuit to open the injectors, NOTHING. I checked the continuity from the injector connector to the ECM, Its good. Anyone know a way to test this stupid VATS module to see If I got ripped off? Anyone near phoenix with an oscilloscope? The module lights up and after awhile the led turns off then back on, I tested the supply and grounds, all good. I have about 5.5 volt on the dark blue F10 signal wire connected to the output of the VATS bypass module. I have tried the 30hz and 50hz signal settings. (note: my starter switch is wired direct) I`d appreciate any help.

 

yeah youre right about the injectors with the ground. Check the ground on the injectors. next test your tps, (throttle Positioning sensor should be at .54 volts with key turned to "on" if its set to high the computer wont fire the injectors. also check you distributor. theres a "pickup coil" (not ignition coil) but the pick coil tell the computer when to fire spark and pulse the injectors. try applying 12volts to just one injector to hear the click for a test, next check the resistance should be =~14.4ohms i think

 

bad ignition module

 

agreed-YEAH test the module, after testing the pickup coils resistance. the module is what the pickupcoil plugs into, require thermogrease upon reinstallation, and autozone can test the module

 

I think I have a bad ECM because now there all OPEN as soon as I turn the key on....
Anyone recommend a place that could test this thing without charging as much as
a new one?

 

you can get a ecm from a auto part chain stores to check, and return or get store credit.

 

IT WORKS! Seriously, Thanks for the info! I checked the ignition module and realized it was not getting power, had a bad connection. After I replaced it and checked the power again the injectors are now pulsing.

 

can anyone tell me where the actual VATS module is located in my 89 camaro rs? ive tried a million things the get this car to start but it wont bc the injectors wont fire. got it down to the VATS module not sending an enable fuel signal and i need to replace the module so help would be great thank you. i cant just do a simple bypass with a resistor bc the module itself is the problem

 

Same as '91 maybe , pic at bottom of page
https://www.thirdgen.org/vats_passkey_system