I got a 1990 firebird, someone had worked on it previous, looks liken the replaced the ign switch, and put a new vats box. They also have wired in some type of bypass chip it has for wires. The car turns over starts for one sec and shuts off. Looking for any ideas someone might have

 

Hard to know until you figure out exactly what was done by PO, and see if you can correct. Here's some info to help:

https://www.thirdgen.org/vats

https://www.thirdgen.org/vats_passkey_system

http://www.austinthirdgen.org/index.php?pid=19

http://www.austinthirdgen.org/index.php?pid=38

http://www.austinthirdgen.org/index.php?pid=41

 

I know that they put in a bypass chip it has four wires, red (hooked up to batt pos. From the ECM), white (which is the fuel enable wire), another white, (which is grounded for 50hz, not grounded for 30 hz,,not sure which one it is) and a black Grd, I don't kno how good the fuel is, it's been sitting for a while. Bt it cranks a lot n fires for about a second, n then shuts right off

 

If it fires, might not be VATS - VATS disables the injectors from firing. If it cranks but doesn't fire, the the fuel injector side of the VATS disable might not be right.

 

It cranks a lot but definitely fires, but for only a sec, n then shut right off...veryfustrating

 

I think you might be looking in the wrong place. You might just be having a fuel issue. Pump weak, plugged filter....

 

Fresh fuel would be a good start

 

Yea tomorrow imma try to get the fuel outta it, and try this all over again, check my fuel psi....ect thanks for the help everyone, I'll get back tomorrow and hopefully have some good news

 

Okay well just playing around with it some, I tested the resistance on the key which was 11.8k ohms, then I check the resistance on pins a6 & b2 of the passkey board which are key resistor pins, n they were not the same. Gotta play with it some more tomorrow

 

If you're going to check resistance just compare it at the pig tail found at the bottom of the column where those wires come out.
But its cranking and starts for a second so I would still look into the fuel system.