Just bought a 89 IROC and I'm trying to bypass the vats. I understand the 2 steps to do so. First is the starter wire. Well that must have already been done cuz it will engage the starter when u turn the key. As far as the resistor, I would get one and wire it in but I have one big problem. The original owner lost the key so I don't know what ohm resistor to use. Is there any way to tell what ohm resistor is needed without the proper key measure the resistance.

 

You buy a pack of resistors from radioshack and solder up each of the 15 possible combinations
https://www.thirdgen.org/vats_passkey_system
until you get the right one.

Faster to buy a variable resistance pot in the correct Ohm range,
http://www.radioshack.com/search/ind...=potentiometer

use a DVM to set it to a required resistance value and try the different values to determine correct one.
Then hard wire in the actual resistors you need

Or you buy the VATS bypass module that sends correct fuel enable signal direct to the computer.
http://www.bakerelectronix.com/products_vats/

Which removes any need for a input ( resistor ) to the VATS module

Requires the starter enable relay mod if not already done

 

Remove drivers kick panel. Behind a tar cover will be the VATS relay. There will be four wires, two heavy gauge two small gauge. Cut and connect the two heavy gauge wires together. VATS bypassed.

 

That only takes out the VATS controlled starter relay.

What about the fact the injectors won't fire without the fuel enable signal from the VATS module???????
If he has a stick car he could always put it in gear and move it down the road by cranking the engine over

 

great way to move a car in and out of a garage while still working in it and not able to fire it up

on topic...the varibale resistor is going to be ur best bet. use a multimeter or similar to set the correct resistant to one of the key blanks and see if it works, if not move down the list till you find the right one.

the easiest way of course is the most expensive, the bypass box.

 

"That only takes out the VATS controlled starter relay."

Where is the rest of the VATS located? ECU?

 

theres an actual vats module burried in the dash. it gets the resistance level from the key, and sends the enable signal to the ECM.

 

I swapped ECUs (LS1) and my trick worked for my application. But it will not work for this one. Sorry for the wrong info.

 

 

Possibly you have VATS deleted in your tune which removes the requirement for the fuel enable signal to the PCM which is why you got to start by bypassing the other VATS component ; the starter relay?.

 

thats what it sounds like to me. the start enable relay is only a part of VATS. the other half is the enable signal sent to the ECM. you tune the need for that signal out of the ECM and all you gotta do is bypass the start enable relay.

 

Well my car is kinda weird. 2 days ago I started it my jumping the starter with a screw driver and it ran. It ran great infact but the whole time it was running the security light was on but before startup it won't even come on when the key first turns.

 

Your start enable relay might have gone out.

 

Well I'm pretty sure it's already bypassed because I can get the key to hit the starter every now and then, I think it's a bad connection at the signal wire on the starter cuz the car sat a while. But the fuel cut part of vats should still be disabling the car. The wires for the ignition lock are just twisted together from when I installed a non vats ignition lock. It must already be disabled cuz the last owner supposedly had computer problems and he had another computer tuned for the cam the motor has.

 

If the VATS light is staying on, then its not bypassed. It could be tuned out of the ECM, but the VATS module itself isnt bypassed. If it was tuned out of the ECM, then the only thing holding you up could be the start enable relay. You can easily bypass that and then be good. But the Security light will still stay on, easliy fixed by removing the bulb for it.

 

Ok well got some more questions. Turns out my starter enable relay was removed and the guy just put a piece of metal across the leads so they were all jumped together. So I took the metal out and tested each lead for voltage and non of them have any. They are all dead with the key on and in the start position.

First question. Shouldn't atleast one of the leads have power and if so which ones.
Second question. Which wires to connect to bypass it? There are 2 heavy gauge yellow wires coming from ignition switch, a heavy gauge green one from the neutral safety switch, and 1 small gauge green wire.

The weird thing is the other day it hit the starter with the key, now it won't. But it would do it intermittedly so it's weird. Any ideas

 

Ignition switch maybe?

 

the start enable relay should always have power, the VATS module controls the relays ground. if its not getting power, that most likely your problem. if it doesnt get power, then it doesnt matter if VATS grounds it out or not, its still not gonna work.

 

highlighted in red is the VATS/ignition system. the yellow wire comes off the ignition switch to the start enable relay. the VATS module trips the ground and lets current flow from the yellow wire to the dark green wire with white tracer. then current flows to your neutral safety switch (aka gear selector switch in autos), then on to the starter solenoid. you just have to start at the switch and probe for power and see where its getting stopped.

 

Have you checked the neutral safety switch?

 

Well got the problem of it not starting with the key. Bad connection at the neutral switch. But now I think vats is holding up my injectors. I think I have a leaky injector cuz it sputters a little when you hit the key only on one cylinder. Also I can't hear the injectors clicking when it turns over either. So what are all the possible ohm inputs for 89 cars. If I cant find that out I'm gonna wire a potentiometer on the vats wire and dial it while I turn it over but that could burn up a starter and don't wana go that route.

 

does your security light come on with the key, then turn off? does the security light come on at all? if the car is cranking but not firing, it points to an non VATS issue.

 

Well the security light does not come on at all until it's running. I think the one time I got it to run I was just lucky. Also I got spark, no fuel. Well a little fuel from the leaky injector.

 

Turns out now that everything is wired correct the security light comes on and stays on. I'm taking the ecu to thunder tomorrow and having them delete vats out the prom.

 

Will this turn fuel n fire back on and be sent the way it is intended

 

In short, no. Could you elaborate on what you are trying to do?

 

I had to bust my ignition to get my car moved and it threw the security system and fits now I'm trying to bypass it completely

 

I have a 1991 Pontiac firebird trans am gta 5.7 t top

 

By "bust my ignition" I assume the tumbler (lock cylinder) broke. If so, I would recommend removing and replacing the lock cylinder. Part should be on the shelf at any parts store. You will be pulling steering wheel and working in the column. Let me know your thoughts.