AmorgetRS

iTrader: (6)

I have run into a problem with my 1992 Firebird (305 TBI). Drove it home for lunch and when I went to go back to the office the car wouldn't start. Not even a click. I notice that the SECURITY light isn't coming on when I turn the car on. I have been having issues with the VATS system so this was something I immediately looked at.

My question is, what gives power to the VATS module? There is a 10A VATS fuse on the fuse block, however that is hot at all times as far as I can tell. I am getting 12 volts at the fuse and I verified that the fuse is good. Does the VATS module get keyed power from another circuit? If I am reading the wiring diagrams right, it gets switched power from the ECM 10A fuse. If that is the case, the car wouldn't of started with the ECM not getting switch power, right?

Also, I have independently verified that the issue is the VATS system as I jumpered the relay under the dash (1992 appears to be special in that the VATS relay was moved from the kick panel to under the dash and is a standard Bosch style relay) and the car started and ran for a second before dieing due to no fuel.

I am worried that my VATS module has died completely...

Ron U.S.M.C.

So with the VATS starter enable relay connecter jumped the starter will crank
every time you try to start it ?


That's important. It should crank every time.


My VATS Module went bad and caused me a ton of trouble until I finally replaced the E Prom chip in the ECM with one that had removed the ECM/injector kill aspect.
With that and the jumper it was basically gone. I even pulled the VATS fuse to make sure it was good and dead.


Here's the bad part. The Shop that burned the chip for me is no longer around.
Here's a thread on how to change the E Prom incase you find some one to burn one for you.
Its actually the very best way to have VATS re -moved, especially if the module is going bad.


LINK = https://www.thirdgen.org/forums/elec...ing-tuned.html

AmorgetRS

iTrader: (6)

I haven't attempted to crank it multiple times, only the one time (when it started for a second), and that was just to confirm that I was dealing with a VATS issue.

I'd prefer to fix it, though if it is a dead VATS module I might just delete it from the PROM until I feel like tearing the car apart. I have all the stuff to tune a TPI motor (G1 adapter, etc) but I've never messed with TBI.

Ron U.S.M.C.

Seeing if it cranks every time with the jumper is verifying.
I always test something more than once before diving in full throttle.

AmorgetRS

iTrader: (6)

I jumpered it again after making sure it was still doing the same thing. It turned over, no issue, but no start. Tried to start it several times, same result.

John in RI

iTrader: (167)

I'm looking at the 91 canmaro VATS schematic and it shows:

The security Light gets it's power from the gauges fuse (with key in RUN BUlb or Start ) and the VATS module provides ground. To test SECURITY light turn key and jumper Ground wire for Security light (Grey wire @ VATS module )

Yes,... that is the case. Full time power to the module from the VATS fuse ( Orange wire ) and gets "switched power" from the ECM fuse ( Pink/Black wire.)

If the starter enable checks out, and you know that module is getting ground and power correctly, but still no SECURITY light; I too would suspect the module of failure.......

Ron U.S.M.C.

Mine was getting power but the problem was "intermittent".
The starter enable relay was jumped and the starter would crank and the car would start most of the time. When it did not start I would wait the required 5 minutes and try again. It did start but that eventually stopped altogether.


I fought this for a very long time until I FINALY found the perfect place to have an eprom module sent to me for my car with the VATS aspect removed.


It had a few extras with it and the car actually ran better than it ever has with no starting problem.
Again, unfortunately the shop is no longer around.
I have done a search for another just to help guys here out but have not found one.


Maybe someone here can come up with one.