Hello all

im having an issue with my 74.
After not using the car for over a year(because working on restoring it) I’m unable to start it up again.

work that I did to it was change the valve springs and valve seals.

i tried starting it about two months ago and it was cranking well.
i came back a week later, tried to start it but only heard a click sound. I figured the battery died, since I left the battery connected.

A week later I replaced it the battery but still, only had a click noice. I checks the voltage drop by unplugging the negative battery cable and connecting the voltmeter in between. After disconnecting a couple of fuses I found that the tail light fuse was draining some of my battery. I took the fuse out and immediately I was able to crank the engine again, after a few cranks (trying to get some new gas to the carburetor. I heard clicks again . So i connected the voltmeter again to see if there was something else draining my battery (voltmeter read somewhere around 12 volts) while the key was out.

i came back a couple of days later (ones I charged the battery) and I checked the voltage again. Between the negative cable and the battery and it started around 11v and slowly came down to 1.6v

i checked all the fuses( by taking off one at a time n nothing seem to make the drop to zero) I tried cranking the engine but still only a click.

anyone have an idea what is going on here?
any help will be greatly appreciated.
thanks

 

Are you getting voltage at the coil,and starter?

 

I will check this weekend, but I think I am, considering that I’m hearing a click and that the engine was cranking for a while before it stopped.
what are your thoughts behind, if there is no voltage on the starter or coil?

 

Welcome to the Corvette Forum aanguiano!

Electrical issues are very normal for most older Corvettes. On the C3 there are a few items that are fairly common issues.

The battery ground strap is short but where it connects to the frame is a great place for corrosion to form. When the corrosion starts the resistance goes up and the starter has a harder time getting full battery voltage to help crank the engine. Check the connections at both ends of the battery ground strap and be sure they are clean and there is no corrosion. Measure the battery voltage at the battery and then measure it using the frame as the ground looking for any differences.

Next I would measure the battery voltage at the battery and then check the voltage using the battery Positive post at the starter and the engine block as the negative. While near the starter be sure there is no corrosion on the battery Positive post on the starter as well.

Older cars sometimes have mechanical brake light switches and those have been known to stick "ON" and this makes the battery lights stay on. It is a more significant drain and can drain the battery fairly quickly.

Whenever you buy a "New" (Flooded Lead Acid) battery be absolutely sure that you charge it up to ~2.5 volts per cell (15 volts on a 12 volt battery) as this will ensure that the electrolyte is not stratified. It is important to charge the battery to the gassing point too ensure it is fully charged. I have seen new batteries at stores with 11 volts or lower in them because of the long term sitting without charging. Our older C3's all came with FLA Batteries and these work the best with their regulators and other parts.

As far as battery drains go sometimes the diodes go bad inside the alternator and they pull current whenever there is battery voltage available. I have a good multi meter and it allows you to use it to check for current being pulled the circuit. I would attach it in between the alternator output and the wire that connects to the alternator output. Most meters are fused up to about 10 amps and it is likely a meter should be able to verify if there is any current going to the alternator. There are other tools and ways of measuring a drain on the battery but using a multi meter is frequently the easiest. With a good fully charged battery you can test the alternator with the engine off. Harbor Freight sells a fuse shaped plug that has a LCD screen that tells you how much current is being drawn though any circuit in your car, very handy device.

I don't use my C3 as often as I used to so I now have a Marine Circuit breaker installed to isolate the battery. During the summer months you shouldn't have to do this but for the longer periods it helps.

Most likely the problem you have is something simple like a corroded or disconnected wire on the car. Start with the simple stuff and work your way up to the more complex potential issues!

You might want to invest in a Corvette Factory Service Manual for your particular year Corvette. Don't use anything but the FSM because they are very accurate and detailed troubleshooting instructions are provided. Rockauto sells the FSM in a DVD format for less than $30 or you can get a printed copy for substantially more. They also make an Assembly Instruction Manual or AIM and those are available from most quality Corvette parts suppliers. I have the FSM and AIM for my C3 and the FSM for my C4 because they don't offer the AIM's for the C4 that I have.

There is a product called "DeOxIt" and it comes in small bottles due to cost. This stuff removes all the corrosion and leaves a protective layer on the metal surfaces in connectors. After cleaning one of my tail lights with it that light assembly was brighter than the rest. DeOxIt is amazing stuff and a real handy thing to have in your tool box when working on a 54 year old Corvette like my C3.

I wish you the very best in sorting out the issues you are having. If and when you have questions just post them on this forum and somebody should be able to help you solve them.

Best regards,
Chris

 

Hello

i finally got to the car this weekend
turn out that the power connection to the battery post was mostly corroded.
i put in a new one added some of that spray you specified and it cracked. 😃

the problem now is that it only cranks.

i added starting fluid to the carburetor and I can hear it start but it dies right away. I also squirted some gasoline with the carburetor and the same thing happens, starts for a second or two, and it dies again.
After cranking I hear a hissing sounds, went to check and it looks like the fuel pressure gauge needle is coming . Also there doesn’t seem to be much gas at the fuel filter. Fuel filter looks like it’s only 1/3 full, even after cranking it for a while.

thanks again for the help, hopefully someone can give me some further guidance on this issue

 

Those fuel filters, plastic or glass, seldom fill up completely. They often drain-back leaving a air gap. That's somewhat normal unless there is blockage upstream.
You say it only cranks. But actually, it fired up. So, most of your electronic issues are resolved. You have spark at the plugs, you have "some" gas at the carb.

This vehicle has been sitting for a long time with Ethanol. Likely the carbs floats are stuck closed because of corrosion at the needle valve & seat.
What carb is this? Who knows what's in the gas tank.

I think a complete rebuild of the carb is coming soon unless you put some type of gas treatment in the tank earlier. For now, I think I would disconnect the fuel supply line at the carb. If this is a Quadra, there is another filter inside. Remove & replace that later, but for now spray Gumout Carb Cleaner into the inlet. That may free things up just to get it running. I suspect the fuel bowl is empty or almost empty.

 

perviously, back in the day when the car started up, I remember that the plastic fuel filter was about 90% full all the time.

i did an overhaul of the fuel system that included replacing the fuel filter, and fuel at the gas tank and cleaning out all the injector of the carburetor (about 4 months back).
i guess the carburetor isn’t as clean as I expected or it got clogged up again.

i think I’m just going to rebuild it again, just to be on the safe side.

thanks

 

pissers are a good indicator of fuel bowel dry or not.

line from pump to carb taken off carb into jar will tell you if it pumps while cranking

but, carb probably should be rebuilt, by a good method, regardless

 

Pissing in a jar with dry bowels, in layman's terms means:

Are the accelerator pumps working? Are there squirts of fuel going into the venturi?

Disconnect fuel line at carb. Again, what carb? Have someone crank it while you dispense fuel from line into jar. But that still does not indicate fuel is going into the fuel bowls.

 

thanks

guess the guys an idiot.
or some one doesn't understand and should pay some else