I started to rewire me car to run a 1995 corvette LT1. I have the basic parts of the C-100 connector with power running to the ignition the interior fuse block. I also have the purple wire going to the starter. when i put the key in i get a tone but turn the key to spin over the engine no even a click. but when i take the wire off and put a volt meter on it it shows 12v. I know the starter works because i jumped the starter with a screwdriver and it spun. Does any one know what would cause this?

 

Did you connect the two heavy wires at the starter relay?

 

Where do we start...

There are a lot of things to do to get her running. Read the FAQ section on LT1 wiring

 

Sounds like the factory VATS. If your car has it, it's in the driver side footwell, left side behind the fascia panel. Relay with two big wires (purple being one of them) and two smaller wires. Remove the relay, jumper the two big wires, and re-test.

 

If its the vats would i have 12v on the purple wire going to the starter if it is not connected iv had a volt meter on it when it is on and off the starter 12v when off 0v when on. with key in start position

 

Im not sure I understand what your saying. Heres my understanding: wire attached to starter, no power. remove wire from starter and you have power, all of which was testing with the key in the start position?

If that was what you meant, Im not sure what you have going on there. I would check to make sure the ground from the battery to block is good, and a good ground from block to chassis.

 

i found the problem it was in the vats i jumped out the relay just like kevinc said. thanks

 

next problem: i got the engine to start and idle for a few seconds then it shuts off im trying to hook up my obd port. I have the serial data hooked up threw the C207 conector but i can not find the Pin location for the computer that transmits the diagnostic test can some one point me in the right direction?

 

Just because you bypassed the relay doesn't mean VATS is bypassed. Your describing exactly what happens when VATS is active, the car will start but then die. This is because the PCM is not getting the signal from the BCM to enable the fuel pump. It will prime the fuel system when the ignition is turned on but the PCM will not allow the pump to stay on without the fuel enable signal, causing the car to idle then die.

 

That would be VATS in the LT1 PCM, it keeps the fuel pump from running after the car is started and basically, you run out of gas on the motor.

 

were is the vats located? i understand what you are saying but i don't know were it is located

 

VATS is programmed inside the PCM, you have to have it programmed out, or buy a vats bypass (I programmed mine out)

 

In my diagrams i have give me the pin location on the pcm for the fuel enable. From what your saying the fuel enable comes from the BCM so i guess i should ask whats a BCM? and am i corect about the wire for the fuel enable it goes BCM to PCM??

 

The fuel enable comes from the chip in the key, that goes into the BCM (Body Control Module) and then to the PCM, best thing to do is have VATS programmed out of the PCM itself.

 

You can also check on Ebay. Theres a guy that sells VATS bypass boxes on there for around 30 bucks. The first one he sent me stopped working after 2 weeks but i was just using it to get my LT1 swap (into a Blazer) able to move. They replaced it after testing it for 2 weeks... The best way is to get it programmed out.

 

i now have every thing to program my pcm but i still dont know the pcm side pin out for the diagnostic line i have the pin sheet for the 4 conectors to the pcm but im not sure the name for the diagnostic link it is not labeled as that on the sheets some one help please

 

http://shbox.com/1/DLC_wiring.jpg

 

thanks thats what i was looking for

 

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ok i got the vats programed out of the computer but the car still wont run it starts for a few seconds then shuts off. the fuel pump is running the entire time along the injectors have a constant curant are they suposed to? Please help

 

The injectors should have switched ignition power and the computer grounds the circuit for the injector it wants to fire. It still sounds lime the vats is enabled. Check your fuel pressure and rerun your program to verify vats is disabled. What program is it?

 

i didnt do the programing i bought a programed computer from performance systems integration and they programed the vats out the emissions egr and air pump

 

I still think the vats is enabled. Maybe somebody has any other ideas?

 

Unplug an injector and stick a test light across the terminals and fire it up again. See if it blinks continuously during run or if it shuts down before the engine stops

Injectors need to see 12v switched. Fuel pump main feed is battery, but the call wire (green) is 12v switched fed by the PCM. Use the test light on those too to verify

 

ok i contacted the company they specializ in ltx an lsx swaps maby they have an idea thanks for the help

 

ok thanks pocket i will try that

 

ok i talked to my friendly neighborhood shop guy and he seems to think its fuel pressure does any one know what kind of fuel pressure i need to look for because i cant seem to find it in any service manual? also would cleaning the injectors help?

 

I'm not sure it's the fuel pressure but it's worth a shot. You should see about 40-45 psi. If your injectors are dirty the car would stumble and not idle right.

 

the fuel pressure is fine but i found the problem the injectors flash the test light and it stops flashing before the engine cuts. im guessing this means the vats was not programed out does any one have any other suggestions?

 

VATS is most probable

 

I will contact the company that did the programing. Thanks
Btw i hate vats haha

 

 

Welcome to post #4, back in October...stuff like this is why I mostly just heckle people instead of wasting time trying to help.

 

Ok so i found out that there is a fuel injector enable along with the vats and they programed it out. now the car runs but i realized i don't have the brown wire coming off the alternator hooked to anything to make the the alternator start charging and the power dummy light anyone know were they go? or were to look?