Corvette won’t start, cranks
12-23-2018, 05:26 PM
#1
3rd Gear
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Corvette won’t start, cranks
So I bought a corvette a couple months ago for a very cheap price. Obviously I knew it was going to have problems
1985 corvette
The car ran for about a month, but one day while driving it had a weird banging/clicking noise, and the car just stopped working
The car, in its current state, does not start, but it cranks when the key is turned. the things that I replaced already or are working and tested:
fuel pump relay
cooling fan relay
all the fuses
fuel pump
99% sure the alternator is working
new battery
im not sure what the problem could be. I tested the fuel pump and it’s working -which, originally I thought was the problem. The relays are replaced too.
It could possible be some sort of fuel problem still though? I would love any input and help, thanks !
1985 corvette
The car ran for about a month, but one day while driving it had a weird banging/clicking noise, and the car just stopped working
The car, in its current state, does not start, but it cranks when the key is turned. the things that I replaced already or are working and tested:
fuel pump relay
cooling fan relay
all the fuses
fuel pump
99% sure the alternator is working
new battery
im not sure what the problem could be. I tested the fuel pump and it’s working -which, originally I thought was the problem. The relays are replaced too.
It could possible be some sort of fuel problem still though? I would love any input and help, thanks !
Last edited by MasonPK; 12-23-2018 at 05:28 PM.
12-23-2018, 05:45 PM
#2
Safety Car
Welcome to the Corvette Forum!
When was the last time the car was started? I would start at the battery and check and clean every connection.
I have a 1988 C4 that I let sit for a while under a cover, it had corrosion on the fuse block and the fuses were not conducting any power. Both the fuse block and the aluminum fuses had a layer of white substance which easily cleaned off. I spent an hour cleaning the fuse block and after re-installing the fuses the car came back to life. There are ground straps that connect the engine to the electrical system, if they break you can loose your ground for a lot of sensors. You mentioned a new battery, are the terminals that connect it really clean as well?
Try ether and see if you have a spark if you have some. It is important to know if there is a spark or not. If it runs on Ether (only for a short time) then we know it is likely a fuel system issue. We have some real experts with your year on this forum, help is on the way!
Do you have or have access to a Fuel Pressure gauge? This is a primary tool on a C4. You mentioned the Fuel Pressure Relay either works or was replaced, how could you determine this? The car is supposed to prime the fuel system when the key is first turned to On mode before starting, most people can hear this if it is happening.
One purchase that is a "must have" if you plan on keeping the C4 is a set of Factory Service Manuals. They are priceless when you have any kind of issue. They sell them paperback or on CD.
How do you know the alternator is working? just curious... Is it getting power when the key is "on"?
I wish you and yours all A Very Merry Christmas and a New Year full of Corvette Experiences!
When was the last time the car was started? I would start at the battery and check and clean every connection.
I have a 1988 C4 that I let sit for a while under a cover, it had corrosion on the fuse block and the fuses were not conducting any power. Both the fuse block and the aluminum fuses had a layer of white substance which easily cleaned off. I spent an hour cleaning the fuse block and after re-installing the fuses the car came back to life. There are ground straps that connect the engine to the electrical system, if they break you can loose your ground for a lot of sensors. You mentioned a new battery, are the terminals that connect it really clean as well?
Try ether and see if you have a spark if you have some. It is important to know if there is a spark or not. If it runs on Ether (only for a short time) then we know it is likely a fuel system issue. We have some real experts with your year on this forum, help is on the way!
Do you have or have access to a Fuel Pressure gauge? This is a primary tool on a C4. You mentioned the Fuel Pressure Relay either works or was replaced, how could you determine this? The car is supposed to prime the fuel system when the key is first turned to On mode before starting, most people can hear this if it is happening.
One purchase that is a "must have" if you plan on keeping the C4 is a set of Factory Service Manuals. They are priceless when you have any kind of issue. They sell them paperback or on CD.
How do you know the alternator is working? just curious... Is it getting power when the key is "on"?
I wish you and yours all A Very Merry Christmas and a New Year full of Corvette Experiences!
12-23-2018, 05:58 PM
#3
3rd Gear
Thread Starter
Member Since: Dec 2018
Posts: 3
Likes: 0
Received 0 Likes
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0 Posts
Welcome to the Corvette Forum!
When was the last time the car was started? I would start at the battery and check and clean every connection.
I have a 1988 C4 that I let sit for a while under a cover, it had corrosion on the fuse block and the fuses were not conducting any power. Both the fuse block and the aluminum fuses had a layer of white substance which easily cleaned off. I spent an hour cleaning the fuse block and after re-installing the fuses the car came back to life. There are ground straps that connect the engine to the electrical system, if they break you can loose your ground for a lot of sensors. You mentioned a new battery, are the terminals that connect it really clean as well?
Try ether and see if you have a spark if you have some. It is important to know if there is a spark or not. If it runs on Ether (only for a short time) then we know it is likely a fuel system issue. We have some real experts with your year on this forum, help is on the way!
Do you have or have access to a Fuel Pressure gauge? This is a primary tool on a C4. You mentioned the Fuel Pressure Relay either works or was replaced, how could you determine this? The car is supposed to prime the fuel system when the key is first turned to On mode before starting, most people can hear this if it is happening.
One purchase that is a "must have" if you plan on keeping the C4 is a set of Factory Service Manuals. They are priceless when you have any kind of issue. They sell them paperback or on CD.
How do you know the alternator is working? just curious... Is it getting power when the key is "on"?
I wish you and yours all A Very Merry Christmas and a New Year full of Corvette Experiences!
When was the last time the car was started? I would start at the battery and check and clean every connection.
I have a 1988 C4 that I let sit for a while under a cover, it had corrosion on the fuse block and the fuses were not conducting any power. Both the fuse block and the aluminum fuses had a layer of white substance which easily cleaned off. I spent an hour cleaning the fuse block and after re-installing the fuses the car came back to life. There are ground straps that connect the engine to the electrical system, if they break you can loose your ground for a lot of sensors. You mentioned a new battery, are the terminals that connect it really clean as well?
Try ether and see if you have a spark if you have some. It is important to know if there is a spark or not. If it runs on Ether (only for a short time) then we know it is likely a fuel system issue. We have some real experts with your year on this forum, help is on the way!
Do you have or have access to a Fuel Pressure gauge? This is a primary tool on a C4. You mentioned the Fuel Pressure Relay either works or was replaced, how could you determine this? The car is supposed to prime the fuel system when the key is first turned to On mode before starting, most people can hear this if it is happening.
One purchase that is a "must have" if you plan on keeping the C4 is a set of Factory Service Manuals. They are priceless when you have any kind of issue. They sell them paperback or on CD.
How do you know the alternator is working? just curious... Is it getting power when the key is "on"?
I wish you and yours all A Very Merry Christmas and a New Year full of Corvette Experiences!
I did replace the fuel pump relay
where would I see if I have a spark, and what’s the best way to go about cleaning the connections
? Thanks!
12-23-2018, 06:40 PM
#4
Drifting
welcome to the forum....do you have a fuel pressure gauge on it while cranking?...a timing light on your sparkplug wire should pulse......if the noise was coming from the hood area, I'd be looking at your distributor.....
12-30-2018, 01:35 PM
#5
Safety Car
As playsdixie mentioned you should listen and try to identify where the sound is coming from. I had a distributor cap that was touching the rotor while spinning and made a strange sound but it was not very loud. An Idea of where the sound is coming from could be very valuable in determining the problem causing the sounds you were hearing before it stopped running.
They make a spark indicator which looks like a small pen that you put against the spark plug boot and it will indicate if it was firing. You could disconnect a plug wire and try a spare plug just be sure it is grounded properly away from anything combustible. Advance Auto will carry something that indicates if your plug is getting a spark. I have an inline boot that has a light inside of it that shows the plug is getting the juice when fired.
Cleaning connections can be done easily using a Pencil eraser or a bottle of chemical cleaner. I use erasers to clean most connections that are small, on bigger ones I use a small copper or brass wire brush. When working on my C4 after my problems I was surprised at how many dirty connections my car had. I also found broken ground straps which cause all kinds of issues. Inside my C68 (electronic A/C controller) I found a plastic connector had actually warped which caused many semi-connected wires to work only when tapped in the right place. On my dashboard the same thing, it would only work when you tapped on it, turned out to be a bad connection there as well.
When the key is first turned to the "run" position the fuel pump will prime the fuel system, you should be able to hear the pump come on (for roughly 2-4 seconds) and shut off pretty quickly if the fuel system is working properly. If you do not hear the pump then you have an issue with 12 Vdc getting to the pump. I have applied power directly to the pump and worked my way back until I found a bad connection at my fuel pump relay. On my 1988 Coupe it has two oil pressure switches, one was disconnected and that kept my fuel system from priming. Under the gas cap is where the wiring harness attaches to the Fuel Pump and Sender assembly and on my car there are three wires. One is larger and supplies 12 Vdc to the pump, the middle one was for the sending unit and the third wire I believe was the ground wire. I use a gadget called a POWER PROBE to allow me to give the pump a good solid 12 Vdc and a battery ground which then fires up the pump and will run as long as I keep the power going to it. Have somebody try turning the key to run and see if the fuel pump is getting power using a volt ohm meter.
Let us know what happens with the fuel pump energizing, if it is happening or not is really important. Next get a fuel pressure gauge and see what is happening in the fuel system on your car. When the car is starting the fuel pressure should be like 42 psi and after shutdown the pressure should drop slowly over an hour or more.
I apologize for taking so long to respond, I was away for the Holidays. I still hope that you have a Wonderful New Year full of fun experiences with you Corvette!
They make a spark indicator which looks like a small pen that you put against the spark plug boot and it will indicate if it was firing. You could disconnect a plug wire and try a spare plug just be sure it is grounded properly away from anything combustible. Advance Auto will carry something that indicates if your plug is getting a spark. I have an inline boot that has a light inside of it that shows the plug is getting the juice when fired.
Cleaning connections can be done easily using a Pencil eraser or a bottle of chemical cleaner. I use erasers to clean most connections that are small, on bigger ones I use a small copper or brass wire brush. When working on my C4 after my problems I was surprised at how many dirty connections my car had. I also found broken ground straps which cause all kinds of issues. Inside my C68 (electronic A/C controller) I found a plastic connector had actually warped which caused many semi-connected wires to work only when tapped in the right place. On my dashboard the same thing, it would only work when you tapped on it, turned out to be a bad connection there as well.
When the key is first turned to the "run" position the fuel pump will prime the fuel system, you should be able to hear the pump come on (for roughly 2-4 seconds) and shut off pretty quickly if the fuel system is working properly. If you do not hear the pump then you have an issue with 12 Vdc getting to the pump. I have applied power directly to the pump and worked my way back until I found a bad connection at my fuel pump relay. On my 1988 Coupe it has two oil pressure switches, one was disconnected and that kept my fuel system from priming. Under the gas cap is where the wiring harness attaches to the Fuel Pump and Sender assembly and on my car there are three wires. One is larger and supplies 12 Vdc to the pump, the middle one was for the sending unit and the third wire I believe was the ground wire. I use a gadget called a POWER PROBE to allow me to give the pump a good solid 12 Vdc and a battery ground which then fires up the pump and will run as long as I keep the power going to it. Have somebody try turning the key to run and see if the fuel pump is getting power using a volt ohm meter.
Let us know what happens with the fuel pump energizing, if it is happening or not is really important. Next get a fuel pressure gauge and see what is happening in the fuel system on your car. When the car is starting the fuel pressure should be like 42 psi and after shutdown the pressure should drop slowly over an hour or more.
I apologize for taking so long to respond, I was away for the Holidays. I still hope that you have a Wonderful New Year full of fun experiences with you Corvette!
01-02-2019, 06:02 AM
#6
Hello,
I am wondering. do you have compression. You said the car made a noise and then stopped. Could that noise be the timing chain breaking. Take off one of the valve covers and then rotate the motor by hand. See if the rocker arms are moving. A noise and then the car stops. Something broke. I had an 1984 started backfiring through the TBIs. I pulled the valve cover and hand spun the motor. The rocker arm on number three did not pivot. I puled the cam and found that the cam so worn it looked like a journal. I hope that this helps.
I am wondering. do you have compression. You said the car made a noise and then stopped. Could that noise be the timing chain breaking. Take off one of the valve covers and then rotate the motor by hand. See if the rocker arms are moving. A noise and then the car stops. Something broke. I had an 1984 started backfiring through the TBIs. I pulled the valve cover and hand spun the motor. The rocker arm on number three did not pivot. I puled the cam and found that the cam so worn it looked like a journal. I hope that this helps.