tchernobog

I changed my fuel filter today, prior to doing so, the car worked fine. Finished up, won't start at all.

I ran into this problem before, and it ended up being the VATS, however, that's bypassed by a resistor.

I'm pretty stumped as to what to try now, I've tried with no resistors and with resistors, and I still get nothing.

I'm stuck at work (a car dealership, funnily enough) and would really prefer to not have to walk 3 miles home.

Fuel pump fuse is fine, it primes, the car just won't turn over.

Any ideas?

BahN

Have you confirmed you actually have fuel pressure? Changing the fuel filter shouldn't effect VATS. I'd rule that out completely. Check for fuel pressure via the Schrader valve on the fuel rail.

tchernobog

The car doesn't crank at all though, wouldn't it crank even without pressure?

BahN

Yes, I was under the impression it cranked as the post just said wont start
Any clicks when turning the key? Lights on the dash?

tchernobog

Well, it's definitely the VAT system.

Now I get to walk to the radio shack 2 miles away in the morning to buy the right resistor.

Fact: Trusting a wal-mart multimeter is not a good idea.

I'm kind of surprised it took this long for it to just not work anymore.

travis401

iTrader: (1)

If the VATS module itself goes out, the resistor bypass no longer works. The resistor bypass just replaces the resistor found in the key. If the module goes out, it will no longer ground the start enable relay, or send the "enable" signal to the ECM (even with the right resistance via the key or the bypass). There are bypass boxes out there that take the place of the VATS module. They get wired to a switched 12v source, and send the "enable" signal to the ECM whenever the key is on. I dont think they ground the start enable relay though.

85Z28NOS

iTrader: (2)

I soldered my spare key with the chip in it to a hidden toggle switch and bypassed the vats that way. Now I can use the toggle switch as a anti-theft device like it was intended without the worry of the key switch failing yet again!( replaced mine twice in ten years before converting to my current set up)

travis401

iTrader: (1)

Same concept as the resistor bypass. Ive seen people rig up the resistor to a plug they can just pull out when they want.

vetteoz

iTrader: (13)

Enable relay has to be bypassed
There is also the possibilty that his VATS is working but the starter enable relay is faulty.
Can be bypassed to confirm operation
https://www.thirdgen.org/vats_passkey_system

tchernobog

Well...I have a 1132 ohm resistance key. I wired in two resistors, totaling 1127 ohms.

Car still won't start.

Any ideas? My security light comes on for a few seconds, then turns off, which leads me to believe the system is working correctly.

I'm using 1/2 watt resistors.

tchernobog

Now my security light doesn't come on at all...

tchernobog

Alright, I'm confused as to how to bypass the starter enable relay, can someone spell it out for me in incredibly plain english?

tchernobog

My starter enable relay clicks rather loudly. Is that good or bad?

I'm sorry to post so much haha, I just need my car

travis401

iTrader: (1)

To bypass the start enable relay, all you have to do, is snip the black/yellow wire and ground it to the body.

tchernobog

Well, it's definitely the relay. I never would have thought of that, I appreciate the help guys.

I tried search for how to bypass it, but every posting I found said a different color wire or a wiring diagram, which I have a horrible time reading.

It's kind of upsetting that something so small can make the entire car not work

It's also a shame that the VATS system works so well, but is so poorly designed. I think next thing I order for my car will be a PROM delete of the entire system.

travis401

iTrader: (1)

Did you get it started?

tchernobog

Waiting on the relay, the only place in town that stocks it was a dealership, and they wanted $49 for it.

I'm sorry, but I'll walk a hundred miles before I pay $50 for a relay.

I'll have it first thing in the morning from advance auto for $14.99. I'm relatively certain it's the relay causing the problem, though. I don't have much electrical experience (body work/transmission work is what I do, odd combination, I know) but I do know that relays are not supposed to click, certainly not loud enough for me to hear through my kick panel.

travis401

iTrader: (1)

Actually relays do click. the click sound comes from the internal switch physically moving. A relay has a trigger wire, that when it gets voltage, physically moves a switch inside the relay to make connection from the constant 12v source wire to the 12v out wire to what ever the relay is powering.

Easiest way to test if the start enable relay is bad, is put the key in and turn it to the on position, then jump the starter. You can either do that with by taking screwdriver under the car and touching it to both terminals on the starter. Or run a wire from the starter solenoid to the engine bay (or splicing into the purple starter solenoid wire in the engine bay) and touching it to the battery. If the car starts, the relay is bad. If it cranks but doesnt start, you probably do have a VATS issue.

tchernobog

I know they do, but it shouldn't be that loud, should it? I called a buddy of mine that does a lot of electronics work (non-car stuff, albeit) and he said it should click, but not that loud.

Also, my security light comes on when I attempt to start the car for a few seconds, then turns off. No flashing, nothing. That means VATS is working correctly, unless I'm mistaken.

travis401

iTrader: (1)

It could just be clicking loud because its old, but if its clicking then the switch is moving which means you should be getting power out. A couple of relays under my hood click pretty loud, my fuel pump relay I can barely hear. They all work though.

tchernobog

I left my jack at work, I forgot to pack it before I got towed, so I'm probably going to have to splice into the wire under the hood. Problem is...I can't seem to find it haha. I've got purple wires that go to the A/C, and one inside the big loom on the passenger side.

travis401

iTrader: (1)

Its a nice sized gauge, I dont remember where mine was exactly on the stock harness, but its probably the one on the passenger side loom.

tchernobog

The one in the loom on the passenger side is a pretty small gauge, I'd say 16 or 18, it looks like an interior wire, to be honest.

travis401

iTrader: (1)

My harness has been highly modified, but the starter wire is the stock one. You can see where I spliced in the (red) wire to run to the battery. It works great when working under the hood alone and you need to pump the starter.

tchernobog

So that's near the firewall, back of the engine bay passenger side?

travis401

iTrader: (1)

It runs down to the starter right around there on a stock harness. But yea the pic is the firewall, right were the heater lines come out.

tchernobog

Gotcha. Figures it would, that's where GM decided to stuff a bunch of crap.

tchernobog

I can't seem to find it. Oh well. I guess I'll know if it was the relay tomorrow morning.

tchernobog

Success. Digging through old threads, found a bunch of postings by Trickster on this problem. Tried jumping pins a and e, car started.

Looks like my relay is dead.

travis401

iTrader: (1)

Congrats, I had no idea about jumping the pins.

Cams4life1697

Were can i find this black/yellow wire to ground? Thanks

JesseDC

I am having the same problem with my 89 RS, i did the resistor trick, still not starting, where is the start enable relay? how do u replace it?
cuz my car makes a loud click when i try to start it too

JesseDC

I think im gonna try jumping my starter, where are the terminals on the starter? pic would help alot

travis401

iTrader: (1)

The terminals at are the back of the starter itself. If the starter clicks when trying to start it, its not a VATS issue, its a voltage issue.

tchernobog

Well. Still no start.

edit - and my fuel pump doesn't prime. Awesome.

travis401

iTrader: (1)

You got it started by jumping the pins though?

tchernobog

Yea, but now it won't do that either.

Buddy that I work with is bringing my jack back to me, so I guess once he gets here I'll be able to test the starter indefinitely.

If I jump it, and the car cranks, it's VATS. If I jump it, and the car starts, what does that mean? Or is that not even possible?

I'll assume that if I jump it and nothing happens that the starter is dead.

travis401

iTrader: (1)

If you have the key in the on position when you jump the starter and it starts, then its not a VATS issue. The VATS would be sending the enable signal to the ECM allowing spark and fuel. It would mean there is a problem in your starter circuit.

If it cranks but doesnt start, then youre not getting fuel and/or spark which would point to a VATS issue. I dont know if jumping the pins bypass the VATS module or not. If it does that would explain why it started if you do have a VATS issue. If it doesnt bypass the VATS but only the start enable relay, then the car wouldnt have started with a bad VATS module.

tchernobog

Got it. I appreciate all the help man.

Question about it possibly being the ignition switch. I've always tested that by turning the headlights on and seeing if they dim when you turn the key to start. Unfortunately, it's a little bright outside haha.

I do, however, have a fan controller, and I can set it low enough to turn on just by ambient heat, as it's probably about 120* under my hood. That being said, if the ignition switch is working, the fan should slow down when I turn the key to start, correct? If so, I can rule that out.

travis401

iTrader: (1)

No clue about that one.

JesseDC

can i get a picture cuz i dont really know what the starter looks like or the terminals for that matter

i know its like at the back of the block right?

tchernobog

It's a big cylinder near the back of the engine, passenger side, near the exhaust. It should have a metal shield between it and the exhaust. There's not too many things with wires going to them at the back of the engine on the bottom of the car, so it shouldn't be too hard to spot.

The terminals are the places where the wires connect.

JesseDC

ok i think i found it ill try the jump tomorrow in the meantime, whats this black box? cuz everytime i turn the key to crank it clicks really loud, is this the starter relay?

travis401

iTrader: (1)

Its a relay, but Im not sure which one. Clicking is normal.

JesseDC

tchernobog, is that the starter relay?

and travis the VATS module, if its bad, where do i get a new one? or is it even worth a new one if the bypass box is only 180$?

travis401

iTrader: (1)

GM dealership, or somewhere that sells GM parts (like GMparts direct), youll need to know what key blank you have and get the matching module. I dont know if they still make them or not though.

The start enable relay is inside the car, under the driverside kick panel (the panel where the hood pop is). Its under a square of black goo stuff.

juanillox8

iTrader: (7)

the bypass from painless wiring is 60 bucks

travis401

iTrader: (1)

http://www.shopatron.com/products/pr...er=64023/302.0

There it is.

travis401

iTrader: (1)

Its $64.50 plus shipping.

juanillox8

iTrader: (7)

yup thats the one... easy to wire and your headaches will go away lol