Hello friends,
How are you? Could you help me, I tell you my corvette does not start your engine, these are the symptoms it has no spark, it does not have 12 volts to the injectors, the key is fine and I bought a new one with the same code or resistance and it worked well, the engine turns but does not start, in the garage they changed the ignition module remains the same problem, the fuse were checked look good. In the garage they tell me it could be the computer, which I don't think they think friends.
Regards.

 

Start with injector pulse with a noid light, fuel pressure test and check for spark with a spark tester.

 

Ok
thanks rgds.

 

Do you know where the fuel injectors get the 12 volts from. Look at the FSM if you have one and find the wire that feeds the injectors power. There probably is a fusible link that is burned out. Do you have 12 volts going to the oil pressure switch.

 

Hello how are you friend, thanks for the advice, I really do not have noid lights, but I have a workshop specialized in Muscle car garage and they are supposed to have good mechanical electrical service.
This Monday they will continue to work in it, I will give you the tips that I have learned from agreements the similar cases that I have seen in the forums, so I will tell you how this evolves.
Thanks greetings.

 

VATS
My car does this on occasion. I have to remove the key from the ignition. Exit the car and close the door. Let the car sit for 10 minutes. I can then enter the car and start it.
Don't leave your key in the ignition when you leave the car.
Mine is 1986

 

If it rains, VATS. If it is hot, VATS. If the car starts on fire, VATS.

How is it VATS if the car cranks?

 

Hello Jose,

Testing the injectors without NOID light is very difficult. The injectors have 12 volts going to them whenever the key is in the Start or Run positions. The computer (ECM) pulls the injectors to ground which means it sends the ground signal to fire the injector. The injectors will fire in batches also and they inject twice for every revolution of the engine. The worse part is the ground signal is sent using Pulse Width Modulation which means a bunch of ground signals coming to each injector very quickly and disappearing. This is why we use NOID lights. They are cheaper than $25 and are really handy when you need them.

First measure the fuel pressure with the ignition key is first turned to start the car, you can hear the fuel pump run for about 2 seconds before cranking. The pressure should be around 40-42 psi when the pump and other systems are working properly, after starting the pressure drops a little but quickly rises when the gas is applied.
Is your car running the fuel pump when you turn the key to try to start the Corvette? If not then you need to check the fuel pump relay to be sure it is working properly. If your car primes the fuel system and cranks but does not start I would guess it is ignition related.

The engine needs to "SEE" oil pressure on the oil pressure switch to allow the fuel pump relay to energize and pump fuel. Behind the intake near the distributor there is the oil pressure switch and oil pressure sensor mounted on a small pipe. That is where the sensor is located, if it does not see any oil pressure it will not energize the fuel system and the engine will not get fuel. Be sure there are no un-connected wires in this area. One of my wires was crimped improperly and was not a constant connection. If the switch does see oil pressure (~4 psi) then the fuel pump relay gets energized and sends power to your fuel pump.

Using a "Timing Light" check to see that every wire has a spark going to the plug or if there is any spark at all. You simply move the sensor that normally goes on cylinder#1 and move it thru all the spark plugs to be sure they are all working. It is important to know if the ignition is working properly and we have a spark at all eight spark plugs. Which ignition module was changed? There is an external box mounted on the passenger side of my Corvette on the AC equipment that has to do with the spark and then there is a controller inside the distributor itself. These gadgets control the spark and other things but have been known to go bad as well.

Lets figure out whether you have a spark and/or fuel pump priming and we will go from there.

Santiago, Chile must be a nice place to have a Corvette! I lived in Bolivia, Colombia and Guatemala so if you need someone to come down and help just say the word. I hope that your English is better than my written Spanish! I was taught to speak not read and write in Spanish, sorry!

Best regards,
Christobal

 

The diagram I am looking at makes the oil pressure sensor a backup and not the make or break. Where do you see different?

 

Ok thanks the famous VATS, I don't like it at all.

 

[font][font][CITA = ctmccloskey; 1600195787] Hola José, [/font][/font]

[font][font]probar los inyectores sin luz NOID es muy difícil. [/font][font]Los inyectores tienen 12 voltios yendo a ellos siempre que la llave esté en las posiciones de Inicio o Ejecución. [/font][font]La computadora (ECM) tira los inyectores a tierra, lo que significa que envía la señal de tierra para disparar el inyector. [/font][font]Los inyectores también dispararán en lotes e inyectarán dos veces por cada revolución del motor. [/font][font]La peor parte es que la señal de tierra se envía utilizando la modulación de ancho de pulso, lo que significa que un montón de señales de tierra llegan a cada inyector muy rápidamente y desaparecen. [/font][font]Por eso usamos luces NOID. [/font][font]Son más baratos que $ 25 y son realmente útiles cuando los necesita.[/font][/font]

[font][font]Primero mida la presión del combustible con la llave de encendido que se gira primero para arrancar el automóvil, puede escuchar la bomba de combustible funcionar durante unos 2 segundos antes de arrancar. [/font][font]La presión debe estar alrededor de 40-42 psi cuando la bomba y otros sistemas funcionan correctamente, después de comenzar la presión cae un poco pero aumenta rápidamente cuando se aplica el gas. [/font][/font]
[font][font]¿Está funcionando su automóvil con la bomba de combustible cuando gira la llave para intentar encender el Corvette? [/font][font]De lo contrario, debe verificar el relé de la bomba de combustible para asegurarse de que funciona correctamente. [/font][font]Si su automóvil prepara el sistema de combustible y arranca pero no arranca, supongo que está relacionado con el encendido.[/font][/font]

[font][font]El motor necesita "VER" la presión de aceite en el interruptor de presión de aceite para permitir que el relé de la bomba de combustible se energice y bombee combustible. [/font][font]Detrás de la entrada cerca del distribuidor hay un interruptor de presión de aceite y un sensor de presión de aceite montados en una tubería pequeña. [/font][font]Ahí es donde se encuentra el sensor, si no ve ninguna presión de aceite, no energizará el sistema de combustible y el motor no obtendrá combustible. [/font][font]Asegúrese de que no haya cables desconectados en esta área. [/font][font]Uno de mis cables estaba prensado incorrectamente y no era una conexión constante. [/font][font]Si el interruptor ve presión de aceite (~ 4 psi), el relé de la bomba de combustible se energiza y envía energía a la bomba de combustible. [/font][/font]

[font][font]Usando una "luz de sincronización" verifique que [/font][/font][font][font]cada cable[/font][/font][font][font]tiene una chispa que va al enchufe o si hay alguna chispa. [/font][font]Simplemente mueva el sensor que normalmente va en el cilindro # 1 y muévalo a través de todas las bujías para asegurarse de que estén funcionando. [/font][font]Es importante saber si el encendido funciona correctamente y tenemos una chispa en las ocho bujías. [/font][font]¿Qué módulo de encendido se cambió? [/font][font]Hay una caja externa montada en el lado del pasajero de mi Corvette en el equipo de CA que tiene que ver con la chispa y luego hay un controlador dentro del distribuidor. [/font][font]Estos dispositivos controlan la chispa y otras cosas, pero también se sabe que van mal. [/font][/font]

[font][font]Vamos a averiguar si tiene una chispa y / o cebado de la bomba de combustible e iremos desde allí.[/font][/font]

[font][font]¡Santiago, Chile debe ser un buen lugar para tener un Corvette! [/font][font]Viví en Bolivia, Colombia y Guatemala, así que si necesitas que alguien venga y me ayude, solo dilo. [/font][font]¡Espero que tu inglés sea mejor que mi español escrito! [/font][font]Me enseñaron a hablar, no leer y escribir en español, ¡lo siento! [/font][/font]

[font][font]Saludos cordiales, [/font][/font]
[font][font]Christobal [/ CITA][/font][/font]

Hi Christobal, it is very well explained and thank you, tomorrow I will take these tips to the garage where my corvette is being fixed, I only do basic mechanics, the specialized thing is a garage only come see muscle car.
Thanks again greetings.

 

Hello my name is Joe,

I have a 1985 that will not run. I saw this thread and thought maybe you could offer some advice. I live on Guam and I do not have daily access to the car. Only the weekends.
I have spark and power to the injectors.
I can get the car to start but it floods. So much so that when I pull the plugs they are soaked in wet fuel.

First measure the fuel pressure with the ignition key is first turned to start the car, you can hear the fuel pump run for about 2 seconds before cranking. The pressure should be around 40-42 psi when the pump and other systems are working properly, after starting the pressure drops a little but quickly rises when the gas is applied.
Is your car running the fuel pump when you turn the key to try to start the Corvette? If not then you need to check the fuel pump relay to be sure it is working properly. If your car primes the fuel system and cranks but does not start I would guess it is ignition related.


Using a "Timing Light" check to see that _every wire_ has a spark going to the plug or if there is any spark at all. You simply move the sensor that normally goes on cylinder#1 and move it thru all the spark plugs to be sure they are all working. It is important to know if the ignition is working properly and we have a spark at all eight spark plugs.
I did this

I have an FSM so if you know where I can find help, in the book. I will look it up.

Thank you and sorry for jumping in.

Joe

 

Hello friends how are you, finally my C4 turned on, the problem was tachometer cable going to the distributor was with circuit break and extra consumption. the good thing was something simple and the ECM was good, I appreciate your cooperation and concern. greetings jose alvear ziegler.

 

You mean the battery connection i.e. pink wire to the distributor, correct. The tach wire just goes to the instrument panel and tells tach speed. I think.