skullandbones

My plan to debug the vette results from my experiences of inconsistency I've had with it. After much rehashing of these events, I concluded I may be experiencing some VATS issues. So part of the plan is to bypass this system (avoid the key cylinder variable and the key itself). But first I got rid of some other potential issues. The fuel pump always has given weird cycle noises like I have never heard from a FP. So I finally replaced it with a OEM version and fuel filter (I did this for some peace of mind). I have a new battery, also. It would not start. So that is where I am with it. It is in it's garage waiting for the next phase of trouble shooting. Although I am retired, I have other competing projects but it is time to get back to it.

My question is: should I investigate the perceived VATS issue or continue basic troubleshooting (ignition fire, fuel rail pressure)? I don't really know where to look for evidence (like codes) to troubleshoot the security. I have gotten countless dash board red light blinking "security" at different times. From what I have read in the service manual, it can lock you out for different intervals, depending on the security level at the time. My goal is to make this car reliable enough to use it as a second vehicle. My wife is tired of fighting with parking and maneuvering the Camaro (18+ft and tank slits for windows). I love it but there isn't enough room in the garage. We were just parking 2 cars in the 3 car garage but now need that space. Anyway I don't need unknowns lurking in the background to bite me when I am using the vette. Have some of you had similar security issues? Has anyone installed the bypass? It's a little black box that plugs into the wiring down near the bottom of the dash. It memicks the key resistance read by the system when starting the car.

Thank you,

WEK

jv9999

It is turning over? If it's a VATS issue, it won't. Also is the security light flashing?

skullandbones

I think the security light is flashing most of the time but not sure if every time. It has turned over every time. I have read tens of references on line and in the service manual. Somewhere I thought it said that at different levels, the system would kill the starter but not other times (deactivating fuel injectors or coil but not starter). So you're saying it is killed every time. If that is true, then I will have to check ignition and fuel supply per normal troubleshooting and see if it starts. Is there any place to check for codes regarding security? What do you think about the bypass option?

Fiberbundle

It is not the VATS if it turns over. When you turn the key into the run position (not the start position) do you hear the fuel pump run for two or three seconds? Have you checked for spark? I would think it is either a fuel or spark issue and start troubleshooting those areas before going to a bypass for the VATS.

ctmccloskey

The VATS system is a major problem for a lot of people including myself. I went to ZIP Products and ordered a VATS Dis-abler all that you need to know is the resistance value of the chip in your key. It took five minutes to install and worked great all for less than $30.

If your car is having any big issues coming back to life start at your battery positive and follow a red wire back to a post mounted on the frame rails. This post is where most of the car's systems gets their power from. On my 1988 Coupe it has seven fusible links attached to the post with small copper ring terminals
which was great when new but mine was covered in corrosion from the top down so I cleaned the parts, reassembled the post and suddenly I had actual battery voltage at my fuse panel. This is where it got weird, the fuses all looked good but had no current passing through them I was measuring 12 volts on one side and nothing past the fuse. The fuses had some light corrosion on them and were made of aluminum, I replaced the fuses with new ones and the car came back to life. Suddenly I heard the fuel pump priming and there was now a radio playing and my windows started working.

Your car might not have an issue like this but when Fiberbundle mentioned the fact that VATS will not let you crank the car if it is activated. So your problem probably lies someplace like the electrical or fuel system.

We will start with the electrical as it is more likely. Before tracking down weird problems be sure to start with a fully charged battery. I would also clean every connection I ran across while working on the car. I would start at measuring the battery voltage, then using the battery Positive keep the lead from your multimeter on the battery positive and then measure the voltage using the engine as ground. It should be very close if not the same number. Then measure the battery voltage at the fuse panel, again it should be very close to the same number. On my car there was a very low number displayed due to the voltage drop I was experiencing from the corrosion. The voltage my fuel pump relay was getting was not enough to activate the relay before the cleaning.

If it is not grounded properly things start acting weird, I found a ground strap that corroded away between the exhaust system and the frame and when I replaced it my power antenna started working again. GM kept adding ground straps trying to keep everything grounded securely.

Good Luck and let us know what happens!

Best Regards,
Chris

skullandbones

The new fuel pump is running as described in the FSM (app 3 to 5 sec). I have not checked the fuel rails for pressure yet. I had a loose wire on the ignition that caused a starting problem when I first got the car but fixed that. I will begin checking for spark and fuel delivery. BTW: I mentioned before that I changed out the fuel pump and filter for peace of mind. When I checked the tank inside with my inspection camera, it looked like new. So I'm not concerned with dirt or other debris in the tank and lines. There was a deteriorated sox that was replaced. This may take a while. I feel a little frustrated since most of the hot rods I've worked on have been frame up builds or rebuilds so I'm used to knowing everything about the car going in. These vettes have complicated systems compared to what I'm used to. It's the electronics mostly: finding the items in tight places even when you have the manual is a pain. I've only had to have it towed once but that's enough for me to want to get it bullet proofed before trusting it again! Thx for helping. I have two owners saying it's not the VATS. One less thing.

skullandbones

Mccloskey,

i think mine is in somewhat better shape regarding corrosion as this car has spent most of it's life in southern Cal and the rest in AZ desert. However, the wiring behind the battery looks like a rat's nest so I am going to follow your lead on tracing the electronics out to the fuse board. When I was building my Cobra, I added 2 grounding blocks to the system (front and back) with wires running directly to the battery. This was mainly for the EFI. So I understand the issues you can have with a compromised ground. I will double check by undoing connection for that occasional hidden corrosion and measure with multimeter to verify. Thx for reminder of basic (step by step) troubleshooting. Never hurts to be pulled back a little!

For All concerned: there was a recall on this model which I do not know if was done on this car (no history). It involved a key cylinder replacement and maybe key replacement as needed. So that potential issue has stuck in my mind since owning the car. I just mention this as part of the info I encountered.

ctmccloskey

Hello Skullandbones,

I live here on the east coast in Northern Virginia are outside Washington D.C. and we do fairly well but they do use the salt and other nasty chemicals on our highways when it snows.

My 1988 Coupe came from the New Jersey area when first purchased and the car looked great when I looked at it. Boy was I dumb, I thought if it was a clean car that somebody used here and there it would be okay. The damage was done, I cleaned the heck out of the chassis but still I have corrosion issues. I will never do that again. My 1968 C3 came from Kentucky or Tennessee and it then lived in Maine for a year before returning to my area. In Maine it belonged to a Body Shop owner who did a beautiful job cleaning it and restoring it. It had been painted but no damage ever found on the body so he painted it Daytona Yellow which is a bright yellow not like the Sun Flower Yellow it came in. The C3 is now 52 years old and aging very well. It is an older 427 ci engine running 12.25-1 compression and a 4 speed and would happily keep youngsters in line.

Have you tried to run a Car-fax on the Corvette? That will tell you if the recalls were done or not I am pretty sure.

I left my C4 unused for 18 months and the fuel literally rusted my Fuel Supply line shut. That good old Ethanol will destroy your fuel lines if left unattended as it absorbs water and goes to the lowest spot on the car before stopping. I treat the last tank of the year with lots of Ethanol Absorber. Anything portable gets the gas completely removed. My Corvettes both only see the roads when it is nice and dry.

The issue with the corrosion at the post near the battery made a huge difference in my car and has helped others here as well.

Good Luck with that Corvette! They are really not that hard to own, you will get the hang of it pretty quickly. A decent OBD1 scanner might not hurt to have as it really can help on some types of problems.

corvetteronw

Check your airbag fuse. If it is blown then the car will turn over but not fire. If that is not it then check the section in the FSM that shows the starting sequence flow chart. Go through the flow chart step by step and you will find the problem.
If I were a bit closer I could drive over and help but my doc will no longer let me drive long distances due to medical problems from my Agent Orange exposure.
Good luck brother.

Oahu750S

I had a VATS issue last Sunday and am going to finally bypass it. I went to
the link below for information on determining the correct VATS number.
I put the OHM meter on 20K and consistently saw 2.36K on both of my ignition
keys. According to the chart requires number 8 and the directions to replace the
VATS are really simple, ordering mine today.

https://mcguirelocksmith.com/service...pellet-number/

I will eventually add a hidden kill switch to disable the car for peace of mind.

Hope this helps.

Chuck

skullandbones

I decided to eliminate two possible failure points in the electronics by bypassing the key cylinder/ key on my car. I will continue to troubleshoot the fail starting. If I change my mind later, I can possibly, put a new key cylinder in. The mechanism doesn't feel tight. I want to get this baby running first and see if it acts a little more reliable (rather than breaking down). Thanks Ron for the heads up on the air bag fuse. I think I did read about that somewhere but did not check it (a little counter intuitive!). Used the link for the locksmith got the right code. Thx Oahu.

WEK