1983sc

iTrader: (6)

I am running a carbed motor in my 92 camaro. i just purchased a new harness since mine is cut up and nasty.

Here is my problem. I have cut what i dont need out. Radio, heater, a/c power locks, windows, hatch release, seats, ect. I dont plan on keeping the ECM in the car. but looking at the diagrams pin B6 has a 5v reference from the ECM. I would like to get rid of the whole vats box and wiring since this is a race only car. I dont really want to get new lock cylinder but i will if i get rid of the vats box correct? is there a way to get rid of the ECM and still use the vats box?

any help would be nice. kinda confused at the moment.

Colt

BigBadLou

iTrader: (3)

Short answer: nope.

Long answer: the VATS box tells the ECM whether the right key is in the ignition, in which case the ECM turn on the injectors. So if you have a carburetor, VATS won't have any effect.

Hope this helps.
Lou

1983sc

iTrader: (6)

So can just cut out the cats box and wiring and use my stock key and lock cylinder?

I also need my Gear selector switch to be legal. will taking the vats box affect that in any way.

1983sc

iTrader: (6)

Any one??

Rolling Thunder

Well heres what i see if your running a carb the ECM isnt really doing much unless this is a l69 or an lg4 or something with the original computer controls? Now all the vats modual really does is dissables the fuel injector pulse which you dont have anyways. Now about the ignition cylinder. The key will work as normal just actuating the ignition switch thats all it ever did. The vats system only sends a everythings ok signal to the ECM to tell it to enable the injector pulse allowing the car to actually start rather than just crank. But again since you dont have fuel injection none of that stuff matters anyways.

BigBadLou

iTrader: (3)

Yes, you can.
No it won't.

Hope this helps.
Lou

FlyDoc

you will have to ground your start enable relay. I have mine wired up to a hidden toggle switch, for some sort of slow down if some one try's to steal it.

tony_cogliandro

iTrader: (3)

you have to understand how vats works.
you turn on the key and it gives juice to the ecm. the ecm is programed to look for the vats. it sends a signal to the vats module. the module sends a signal to the key monitor asking for the correct resistance in the key.
if the ecm does not get conformation that the key is what the vats expects, the system shuts down for 4 minutes and will do that each time it fails to get the correct signal.
you can take out the vats module but that will not help, the ecm will still not get the conformation signal.
you can reprogram the ecm not to ask for vats conformation - then you can take the vats module out and the key.
good luck.

BigBadLou

iTrader: (3)

Yes, if the 92 still has the Starter Enable relay, it would have to be either taken out or bypassed.

And to clarify, the ECM does not send anything to the VATS box. The VATS reads the resistance of the key pellet and if it matches the pre-programmed resistance in the VATS box, it outputs a specific waveform singal to the ECM. That's the only way the ECM is informed of the correct key in the ignition.

Hope this helps.
Lou

tony_cogliandro

iTrader: (3)

no the computere and the vats communicate. that is why you can disable the vats by reprograming the ecm to not ask for a vats.
if it was just a matter of pulling the vats module out then any thief could do it and it would never work as a security system.
there has to be communication between the vats and the ecm or it would be useless.
they are an intertwined system and communicate with each other. and yes the computer asks for the vats information and then gets it.

BigBadLou

iTrader: (3)

I guess we just use different wording. You say "communication", I say "input" and "detection".
The only wire between the VATS and ECM is the blue wire on the Cranking Fuel Enable pin (B6 on TBI or F10 on TPI and MPFI). The ECM senses the predefined waveform on it, that's the only communication between these two.
The 80's computers weren't as sophisticated as today's models that use CAN or similar to interface with intelligent sensors all over the car.

Hope this helps.
Lou

snardos

Would anyone happen to know what kind of signal the ECM is expecting from the vats module? I read somewhere that it is a 50Hz square wave but that seems to simple. Mine is acting up and I just want to build a simple to circuit to tell the ECM that everything is good and let me start the car.