Very new to the forum and very much need the help. Purchased an 89 a few months ago and drove it around to have some fun before pulling in the garage for a complete overhaul. I when through the entire suspension replacing all the bushings, cleaning aluminum parts, upgrading swayers and adding Coilovers (looks awesome)... One of the biggest purchases was to add the new intake system from First Performance Center. I also took out all of the emissions stuff to include EGR, AIR pump, manifolds, etc... Added the AIR pump replacement pulley and some new headers. Got everything connected (at least I hope), installed new battery and when I went to turn the key...NOTHING, not so much as a sound. I know about the VATS system and I purchased the bypass connector, but that didn't do anything. I know I have juice going to my starter, but it won't even attempt to crank. I ordered a code reader that will be here in a couple of days, but I'm really puzzled as to what this issue might be. I know it started just fine when I started working on it so it seems like I'm missing something, but it's just not as obvious to me as it might be to some of you. I did pull the dash out and have the gauge cluster rebuilt as well as the heater controls. I put in a new flex circuit for the controls and warning lights. When I turn the key on everything seems to function properly. I get a flashing SECURITY light when I have the key in the ignition and then solid SECURITY when I turn the key. I also get the CHECK ENGINE LIGHT (obviously), the ANTI THEFT light, and the BRAKE light when I try to start the car. Nothing flashes when I try to start either.

A second question... Does anyone know how to bypass the whole thing in order to start the motor?

Thanks for any help and support.

 

First, Welcome to the Corvette Forum mit01006!

What you are describing is a situation where the battery is not making anything happen. First, start at the battery and measure the voltage, then go inside the passengers side and check the voltage at the fuse block. Also measure the ground of the engine using the Red lead on the battery Positive and the black lead on the engine block metal. The voltage measured at the engine should be the same as the battery if you have a good ground.

Try and check your Starter motor and see if the 12 volts is at the solenoid. If you have a remote starter you might try and see if the engine will spin when the starter gets power. One wire to solenoid and one wire to Starter and you should be able to spin the engine over.

When you installed the "New" battery it was brand new, right? Any time I install a new battery I always charge it completely First to ensure that it is ready for action. A battery that has sat for a while can stratify the electrolyte and produce a limited capacity. It is important that they get to the gassing stage of the charge to completely charge your battery. I also clean both the posts and the connectors and then assemble them and coat them with battery grease.

What kind of intake are you describing? I am not familiar with First Performance Center. What type of system is it?

On your battery there should be two Red wires coming from the battery connector. The large Red wire goes to the Starter and the second smaller Red wire supplies power to a Post (on my 1988 C4) that supplies 7 Fusible Links that in turn supply power to the fuse panel. The post on my C4 is under the side cover at the front of the drivers side. To find it follow the smaller red wire from the battery connector. Mine was covered in rust and was causing a major low voltage situation. The seven fusible links power most of the system in the C4 and if it is corroded you can develop issues.

Does your ignition key still have the resistor in it? If not that might be the problem. They sell devices to disable the resistor checking system. I did mine after an intermittent issues with it not recognizing the keys.

Lets us know of anything else you can think of as it might help solve your issue. We will try to help you in any way we can!

 

Thanks for the suggested areas to look at. I had already charged the battery, but checked it again and it checked out okay. I validated the fuses were all in order and even purchased a GM code reader to run. The check engine light code flashed revealed a code 12. From my understanding this is just a normal code to inform everything is ready to start, but I'm not 100% sure on that. I have a new starter I can put in, but for whatever reason I can't seem to figure out the proper way to test it. It's a 2 connection type starter and I've tried a couple of ways to do it, but neither seem to do anything. If I can figure out the right way to test this one I would probably have better luck testing the one on the car.

They key seems to be in good shape. I tried cleaning it up a bit and pushing it in and out of the ignition, but that didn't do anything. I called the GM dealer in town and they have a lock smith who can get me new keys, but wasn't open on the weekend. I will try to get a new key this week though.

On a side note, I know I have power running to the starter (don't ask me how I can confirm that... it was quite the fire works show).

Just an update and some additional info, not sure if it will help.

 

Code 12 means that there is no pulse from the distributor pick up coil, which you don't b/c the engine isn't rotating.

You can bypass the start enable relay to crank the engine w/the starter, but that won't get you running, b/c the FEDS portion lf the VATS still won't allow the injectors to fire, I don't believe. So...that won't get you much.

Do you know that VATS is the issue? I THINK your security light is functioning correctly, which makes me wonder about the p/n/clutch safety switch or ignition switch.

 

Yeah, it's an automatic, probably should have said that... I don't for for sure it's a VATS issue, I'm not sure what's causing the problem. would a connector of some type need to be connected to ensure the starter turns over?

A bit more info on the air intake system I installed. It's a FIRST air intake for the C4 L98. One thing it does do it come with a PROM replacement chip to program the new air flow and fuel injectors. Not sure if that would keep the starter from turning over or not, but I did replace the PROM.

 

I don't think the PROM would prevent it from cranking.

I'd get a test light and start following power. I'd start at the starter (small wire) and work back to the ignition switch. Where ISN'T the power?

 

I think your advice may have helped me figure out my issue, but I won't know for sure for a couple of days. I ordered the VATS bypass connector, BUT did not realize I just ordered the one listed on the page without selecting the correct resistance for my car. I started going through the entire car with my multimeter and when I got to the key it read 2.98 ohms, but when I checked the bypass it read .38 ohms. I got back online to look at the bypass options and quickly realized I ordered the wrong one. I have a new one on the way, but won't know if that solves the issue or not until I can try it out.

 

The "Security" light tells you if it's working or not. No need for a meter.

*I* would want to know what is going on in the starting circuit, personally.

 

So the VATS bypass does not seem to be working. After checking the ohms from my key (2.98) I got the bypass closest to my key's reading and the one lower and the one higher just to be safe and none of them work. I then purchased individual resistors and created my own bypass and started at 2.95 and went up in 10 ohms up to 3.00 and nothing. I waited the 5 min between attempts, but nothing seems to be happening. Any additional thoughts?

 

Not sure what you did to get your spark shower. The larger of 2 connection goes directly to your battery and will always show voltage unless there's some break in the wire. Current flows when you turn the ignition switch that goes through a starter relay that VATS plays a part in closing it and continues on to the smaller wire connection. As someone has stated twice in this thread, you need to check voltage in this circuit.

 

If the car ran before you worked on it logic says you missed something during reassemble. Recheck your connections at the distributor to start....

 

FYI,
I have an 87
heres what happened in my situation.
n my car was never raced abused ever!!

car wouldn’t crank-nada zilch zero balance.
i believe security light was illuminated.
battery, connections everything was perfect. It wasn’t a key issue.
To cut all the fat off the bone,
installed a vats bypass relay, it has different frequencies on it,
u have to try them one at a time until u find the correct one. Problem solved.
In several years since corrective action was taken 0 problems.
Time necessary for corrective action w/ parts in hand-Maybe two hours.

Caution: be advised ur security theft protection will be disabled so park accordingly. I installed it behind the bread box- glove box.
i can get u the exact part # if u need it

Gary 😎🇺🇸

 

I have an 86.
i got howed home two weeks ago.
in my infinite wisdom, i thought it was the fuel pump, calld AAA, and had it dumped in front of my house.
i made a jumper, and jumpered the fuel pump oil pressure switch, and i heard the fuel in the rail.
wouldnt start .
so leaving that jumper in, i jumpered the distributor to the battery, and it started right up.
symptom?
driving along at 45 mph, car started bucking and quickly got worse and shut off.
acted like the fuel pump was quitting.
so got it i. The garage jumpered.
helms manual shows power comes tight off yhe ignition switch.
pulled the seat and got to the switch.
the plug was clipped on by only one catch.
pushed it down, and started without any jumpers.
so in your case, i would check power to starter in start

 

 

 

I jumpered the pink wire to battery, then turned the key, started right up, so it was power from ignition switch, not the fuel pump like i thought

 

Outstanding 👏 👏 👏
hey coupe guy or the wizard of oz with the schematics
Ur mission should you choose to accept it😎🇺🇸
help prevent a discombobulated corvette owner who has had his vette on jack stands since
Thanksgiving from bulldozing his car into the Grand Canyon,
by going to the schematic for an 87 n find out what the black ribbed lead from the ecm harness connects to / it’s location is behind engine bay behind distributor in tranny tunnel between tranny n body. It’s possibly keeping me from adjusting my idle- she’s not happy. Can’t get to it, may have to jack the motor out.





TY
Gary😎🇺🇸

 

EGR Temp Switch. Has nothing to do with idle, I’m afraid.

 

TY
i accidentally unplugged that egr temp switch. I had swapped to vortec heads on my 87, I was having no success timing the vehicle (vehicle won’t idle with computer connected)
I was trying to eliminate any reason for it. My EGR has been removed- this helps tremendously.
Once I put my engine back together
( intakes removed to reconnect that egr switch)
ill find a way to get my performance chip scanned/ tuned, n I should be rolling hopefully. It’s been a long road goin through a head swap in a temp garage setup. TY, I’ll tape it or something n be done with it.
I really appreciate it. I have the full red maintenance books for a 93, but not what I need an 87.
once again TY
Im going to have to find a good scanner/tuner n buy it I guess. I’m in New England, finding locals who r knowledgeable in this is a challenge.

Gary🇺🇸

 

I’m in Old England, even more of a challenge!