Does the vats only disable the fuel pump or does it disable anything else in the ecm? Does it keep the injectors from pulsing or keep the distributor from sending a pulse signal to the injectors?

Nick

 

As far as I have gathered, the VATS affects two things:

1. Starter relay
2. Injector pulse

Since you are probably using your stock starter wiring, the relay control is negated. As I understand, the factory starter wiring in VATS equipped vehicles incorporated a relay which must be closed by the ECM before power can be delivered to the motor.

I believe that there is a two second delay after the vehicle starts in which the ECM "listens" for the VATS module signal, which we are trying to emulate. If it does not recognize this signal, it stops pulsing the injectors, and the engine dies. This is where I had trouble. I do not believe that the fuel pump is manipulated in the process.

 

I also believe that the ecm will not pulse the injectors until the vats is disabled. I can turn my engine over but I am not getting any pulses to the injectors. I checked everything else that i could think of. I do have spark, but no injector pulse from the distributor.

Nick

 

well it all depends on witch one you have I or II in know I only controlls the fuel pump not sure on II I will have to look it up.

 

My ecm is out of a '91 Formula. ECM is a 7730. Appreciate any info. you may have.
Nick

 

I can only take a guess but, it may be vats II ??? none of my books here say I would have to check at work.

 

Just read info. about VATS at www.jimsperformance.com . It is true, the vats does disable the injectors until it receives the necessary signal. Check out that site, it has a lot of info. and neat stuff. Jim is a great guy and has been very helpful.

Nick

 

looks cool I will have to spend some time there.