im going down to check out and probably buy a 3.4 from a 94 firbird on saturday. giuy only wants 100 bucks.

anyway, he bought the car at auction and has no keys. says that the car cannot be started due to that and the VATS system. si there any way to bypass all this in the junkyard so i can ear it run before i spend the money? im pretty handy with wirung, but this may be over my head.

thanks
Michael

 

You need a vats bypass module or 15 different resistors and a lot of time ( 4 minutes each resistor until you find the right one) The vats bypass module has three wires 1 ground, 1 ignition hot, and 1 to the pcm to take the place of the vats module. I've had to use them when I've swapped vats computers into non vats cars and when ignition cylinder wires break. EBay has them for about $20 I think the 94 and newer use a 50 hertz signal while some of the older years use a 30 hertz signal. You can get a 15 pack of resistors from EBay for about $5 but if you dont know which one you need you might be there awhile.

 

I'd just go with the bypass module... You can't commercially buy resistors to match at least half of the key resistance codes (been there, tried that), so you would end up soldering a number of them together on a large board to find which works.

:edit: (Scratch what I said here... the only ECM that would work is on select 93 Grand Prix's)

 

the research on the vats that ive done says that the way it works is that it cuts the signal to the starter solenoid and fuel pump. if this is true, could i hardwire the oump to the battery, and jump the starter terminal after bypassing the ignition switch? that sounds a lot quicker and cheaper to do in the junkyard, and then find the correct bypass stuff when i do the swap.

michael

 

Your research is a little fuzzy. Without the VATS signal, the ECM (PCM in this case) will NOT pulse the fuel injectors. The pump will run, but there won't be any fuel delivery beyond the fuel rail (no fuel injection to cylinders). You could crank several batteries dead and not fire that engine without the VATS signal.

 

Go to your chevy dealer with the VIN and the title.

They can make you a VATS Key.

 

... if the lock cylinder hasn't been replaced, and if he wants to shell out half again as much as he's paying for the engine just to have the key cut, and if he takes the actual owner of the car with him and they let him do that...

 

Yeah, but if worst comes to worst.

We had to do that with my dads ranger, The keys had been left in mexico...

 

im not familiar with vats but couldnt you turn the motor over by jumping the solenoid and disconnecting the distributor from the ecm?

 

One word: NO.

First off, a 3.4 doesn't have a distributor. Unless, of course, you're talking about a 3.1 or 89 2.8, for which the answer is still NO.

Second, disconnecting the dizzy doesn't do any good as the ECM won't know the engine is trying to run.

Third, read my post a few posts above to find out why you NEED the VATS. Or, better yet, I'll just repost it:

 

hey man chill out it was just a suggestion im not some master mechanic or anything like that

 

well, i bought it anyway. couldnt hear it run, but the plugs looked good, the oil is dirty but uncontaminated, theres not a lot of leaks, and why would they put a brand new clutch, ciol pack, water pump, belts, and hoses on a motor that was going south?

ill pop the pan and check the bearings after a compression test and verifying good cranking oil pressure. if it all looks good, ill just run it like it is and see what happens.

 

I'd check the bearings first before I did the compression and oil pressure tests. You might as well as long as the engine is out. Not to mention you don't want to make a problem worse. Also, while you're down there, it might be a good idea to slap a new oil pickup screen on the pump.