birdman_29

iTrader: (1)

Hi, I changed the prom in my ECM, and other things for my 350, that was previously a 305. Like the knock sensor the ESC module fuel injectors. The motor ran before I put the chip in, but right after it ran for a few seconds then died. Haven't a hard time getting it to run. My question is, is this a VATS problem that I've come across because I've changed something electronic, that the computers doesn't recognize through the VATS module? Or something like that. An if it is how do override it or where do I go from here? I'm already talking to Brian Harrison that burnt my prom for me and he doesn't believe it is a Vats problem. I don't know

BlackenedBird

iTrader: (5)

VATS is a completely separate module that is not "smart" or part of the ECM or its chip. It is just a module with its own circuit that only functions correctly with the correct resistor valued key & allows the signal to be sent to turn on the fuel pump (or was it the coil that doesn't get powered & you can flood the engine due to lack of ignition?). I forget which way VATS works, but it is one of those two.

birdman_29

iTrader: (1)

ok, so why did the motor die on me after I changed the prom?? It was running fine before. The guy that did the chip said that if it was the chip error there would have been like a ses light flashing or something in that nature. Can you explain more on a resistor valued key?

birdman_29

iTrader: (1)

I'm not trying to see who is wrong or anything I'm just trying to get to the bottom of the problem.

BlackenedBird

iTrader: (5)

VATS bypass is pretty simple. Get the correct resistor from Radio Shack, insert the 2 ends into the wiring plug & it will no longer even look for the correct key, except the correct cut just like your house key does.

VATS bypass is really simple if you wanted to try that, but if the Module itself has died, then the bypass trick won't work either.
http://www.austinthirdgen.org/index.php?pid=41

birdman_29

iTrader: (1)

So, what I'm getting is that the little chip in the key is for the VATS. VATs controls the firing of the fuel pump to the injectors correct? Ok now I'm really not sure where to go, I'm gonna have to go back out and double check see if I'm getting any fuel, and if so than that means that the VATS isn't the problem. If I get fuel then I'm just gonna change out the chips and see if that makes any difference.

birdman_29

iTrader: (1)

I just hooked the battery up and I saw fuel through the injectors, battery wasn't charged enough to do anything else, motor started to make that clicking noise, not enough power.
I'm charging up the battery and I'll try again later, if I get fuel then I'm gonna get the chip out and change it.

BlackenedBird

iTrader: (5)

Why change the chip? Unless it is the wrong chip (highly doubtful), then it is not a VATS problem. It is the Module that is looking for a specific range of resistance. There are 15 different resistors that you'd have to try on the VATS bypass, with a 2 minute wait between each try. And if it is the Module itself that broke, you'd have 15 failures. The bypass only works if the Module is good.

Check & see if the plugs are firing when you try to start it again. As I said above....I can't recall if it is fuel or spark that VATS shuts off.

And how did you "I saw fuel through the injectors"? Short of pulling an injector off the car, you can see the fuel. So I'm puzzled by your statement on that part.

birdman_29

iTrader: (1)

ok, correcting myself I saw fuel coming out of the pillars into the dishes in the TBI. I did change out the chip cause I still had the original one put away, it only took me 10 min. charged the battery for 10 hooked it up and turned the key and it fired not just roll over again and again. I changed it because that was the last thing I really did that mattered electronically to the car.

BlackenedBird

iTrader: (5)

I had TPI stuck in my head. Of course you'd see fuel spray on a TBI. Stupid me! LOL

So your saying with the OEM 305 chip it fired, but with the new chip it didn't? That kinda points to a chip problem. Put the OEM chip back in & see if it fires. If it does? I'd blame the custom hip. If it doesn't? Something else just happened to go out at the wrong time.

Try the old chip & let us know & we can go from there.

birdman_29

iTrader: (1)

I got good reading today with the OEM 305 chip, fired right up after a few adjustments with the distributor. Ran about 10 minutes I shut it off and then I fired it up again without a problem. I'm gonna try a few more times make sure battery is in good shape, I'm not getting close to running out of gas etc. I'll let ya know what happens.

saturnion

Where is the vats module and what does it look like on a 1989 GTA,help please anyone

BlackenedBird

iTrader: (5)

The VATS Module is deep inside the dash about in the middle. Basically have to remove the whole dash to reach it. That is how I found the last one I saw.

EagleMark

Does anyone know what the signal is from VATS module to ECM? Manual says it's PWM. ECM looks like it has or wants a 5 volt reference. Is that all it is?

To help the OP if you don't have a good batterey fully charged and a good charging system? First your fuel injection will not run right, if the starter takes it's last few volts down below 12 then the relays won't even come on to run EFI.

Along with the VATS (theft deterant module) that needs a proper key resistence from key to cylinder to module (can unplug under steering coulmn and insert correct resisters to eleimanate key pellet and ignition key cylinder and wires to plug), then module sends signal to ECM AND provides a ground for theft deterant relay. If you change the ground on the relay to ground, you changed the theft deterant relay into a starter relay. Good thing! Then if you can disable VATS in ECM chip you have bypassed the entire system. On my B body LT1 I then pulled three fuses. Poof! Gone!

l_dis_travlr

The VATS module reads the ign-key resistance pellet, and then
a: closes the ign. starter relay
b: sends a 5v 30hz signal to the ECM,
which then starts fuel & ignition control.

Wrong resistance, or module failure, and there will be NO RESPONSE
whatsoever when the key is turned. So if the engine fired, and ran at all
with a different chip, look for something other than a VATS failure.

(And if the VATS module fails, GM is REALLY proud of them.
IMHO, tune it out of the ECM binary, or get a cheap oscillator module
that fools the ECM with a 5v/30hz signal.)

Good luck