69 Corvette won't start - electrical problem?
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
69 Corvette won't start - electrical problem?
In a nutshell: the starter is reving the engine and gas is flowing to the carbuerator, but the engine will not start. Not a cough, not a sputter, nothing.
Back Story: The battery always tended to drain when the car was left unused for a while. We installed a batter shut-off-switch to prevent this, but I forgot to switch it off last time I drive the car.
A week later, the batter was too low to turn over the engine. Got the car started once with jumper cables, but a couple minutes after disconnecting the other car battery, the Corvette engine died and would not start again.
Took the battery into Autozone, where they charged it and said it was in good shape. Put it back in car, and it got the starter going, but the engine still would not run. After a few minutes of trying, the battery ran down again.
So, power gets from the battery to the starter, but there is no internal combustion. Could there be some kind of power drain preventing the spark plugs from firing? Any ideas?
Back Story: The battery always tended to drain when the car was left unused for a while. We installed a batter shut-off-switch to prevent this, but I forgot to switch it off last time I drive the car.
A week later, the batter was too low to turn over the engine. Got the car started once with jumper cables, but a couple minutes after disconnecting the other car battery, the Corvette engine died and would not start again.
Took the battery into Autozone, where they charged it and said it was in good shape. Put it back in car, and it got the starter going, but the engine still would not run. After a few minutes of trying, the battery ran down again.
So, power gets from the battery to the starter, but there is no internal combustion. Could there be some kind of power drain preventing the spark plugs from firing? Any ideas?
Melting Slicks
Joined: Jan 2007
Posts: 2,589
Likes: 5
From: Salisbury Maryland
My choke is disconnected, so I have to manually shut the valve until I get my new carb on this month. After sitting a few weeks, it takes probably 15 seconds to fire up.
Sounds like a fuel delivery issue. Filter or pump perhaps?
Sounds like a fuel delivery issue. Filter or pump perhaps?
Melting Slicks
Joined: Dec 2006
Posts: 2,669
Likes: 3
From: Kingston Ontario
Must go back to basics. You need fuel and spark.
If you have fuel as indicated then you need to check for spark at the plugs. Remove a spark plug; connect the spark plug electrical lead to it and have the engine turned over, while the spark plug is grounded at the threads and look for a good spark.
Make sure you have fuel and electrical. Removing one or the other means no ignition.
If you have fuel as indicated then you need to check for spark at the plugs. Remove a spark plug; connect the spark plug electrical lead to it and have the engine turned over, while the spark plug is grounded at the threads and look for a good spark.
Make sure you have fuel and electrical. Removing one or the other means no ignition.
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
pull a plug wire, and slide the boot back exposing the metal tip,
and hold it about 1/4" from Gnd.
have some one crank the engine, do you get spark ?
keep you hands back, away from from the tip !
Do you actually see gas shot from the carb. when you push the accelrator ?
and hold it about 1/4" from Gnd.
have some one crank the engine, do you get spark ?
keep you hands back, away from from the tip !
Do you actually see gas shot from the carb. when you push the accelrator ?
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
In a nutshell: the starter is reving the engine and gas is flowing to the carbuerator, but the engine will not start. Not a cough, not a sputter, nothing.
Back Story: The battery always tended to drain when the car was left unused for a while. We installed a batter shut-off-switch to prevent this, but I forgot to switch it off last time I drive the car.
A week later, the batter was too low to turn over the engine. Got the car started once with jumper cables, but a couple minutes after disconnecting the other car battery, the Corvette engine died and would not start again.
Took the battery into Autozone, where they charged it and said it was in good shape. Put it back in car, and it got the starter going, but the engine still would not run. After a few minutes of trying, the battery ran down again.
So, power gets from the battery to the starter, but there is no internal combustion. Could there be some kind of power drain preventing the spark plugs from firing? Any ideas?
Back Story: The battery always tended to drain when the car was left unused for a while. We installed a batter shut-off-switch to prevent this, but I forgot to switch it off last time I drive the car.
A week later, the batter was too low to turn over the engine. Got the car started once with jumper cables, but a couple minutes after disconnecting the other car battery, the Corvette engine died and would not start again.
Took the battery into Autozone, where they charged it and said it was in good shape. Put it back in car, and it got the starter going, but the engine still would not run. After a few minutes of trying, the battery ran down again.
So, power gets from the battery to the starter, but there is no internal combustion. Could there be some kind of power drain preventing the spark plugs from firing? Any ideas?
You say it started at one point while you were boosting it and once you disconnected the booster cables it died. thats typical if the alternator is bad. The car (spark plugs) will spark off the battery until the battery has no more juice. Or in this case disconnecting the cables.
Jim
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
Thanks for the suggestions.
To answer questions asked above:
1. The parking garage where the car is stored had some dampness from heavy rains during the time the car was idle.
2. I do see gas shooting in the carb.
I will check the spark and the alternator.
To answer questions asked above:
1. The parking garage where the car is stored had some dampness from heavy rains during the time the car was idle.
2. I do see gas shooting in the carb.
I will check the spark and the alternator.
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
Just to wrap up the story: the problem was no spark; the cause turned out to be the distributor.
Replaced it, charged up the battery, and now the car starts right up.
Thanks again for pointing me in the right direction.
Replaced it, charged up the battery, and now the car starts right up.
Thanks again for pointing me in the right direction.
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Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
Old problem crops up again
I thought I had this problem solved months ago, but now it is back.
After replacing the distributor cap, the car started for a while. Then after sitting for a week or two, it would not start. Same situation as before: battery is charged, starter is working, gas is going to the engine.
I figured I must have left some wires loose when replacing the distributor cap, but I didn't have time to deal with it that day. I went back a week later, jiggled all the wires, made sure nothing was loose, and the car fired up like there was no problem. I let the engire run a few minutes to charge the battery.
Went back two days later (yesterday) and again the car would not start.
Considering that this problem comes and goes, where would you look first? The distributor? The alternator?
After replacing the distributor cap, the car started for a while. Then after sitting for a week or two, it would not start. Same situation as before: battery is charged, starter is working, gas is going to the engine.
I figured I must have left some wires loose when replacing the distributor cap, but I didn't have time to deal with it that day. I went back a week later, jiggled all the wires, made sure nothing was loose, and the car fired up like there was no problem. I let the engire run a few minutes to charge the battery.
Went back two days later (yesterday) and again the car would not start.
Considering that this problem comes and goes, where would you look first? The distributor? The alternator?
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If the car is still in the wet garage the moisture could have collected in the cap again,check the points for moisture. Check to be sure the coil is firing by removing the coil wire from the distributor and holding the end about 1/2" from one of the shield brackets and have some one crank the engine and watch for a spark.
Racer
Joined: Dec 2003
Posts: 275
Likes: 6
From: NY
I thought I had this problem solved months ago, but now it is back.
After replacing the distributor cap, the car started for a while. Then after sitting for a week or two, it would not start. Same situation as before: battery is charged, starter is working, gas is going to the engine.
I figured I must have left some wires loose when replacing the distributor cap, but I didn't have time to deal with it that day. I went back a week later, jiggled all the wires, made sure nothing was loose, and the car fired up like there was no problem. I let the engire run a few minutes to charge the battery.
Went back two days later (yesterday) and again the car would not start.
Considering that this problem comes and goes, where would you look first? The distributor? The alternator?
After replacing the distributor cap, the car started for a while. Then after sitting for a week or two, it would not start. Same situation as before: battery is charged, starter is working, gas is going to the engine.
I figured I must have left some wires loose when replacing the distributor cap, but I didn't have time to deal with it that day. I went back a week later, jiggled all the wires, made sure nothing was loose, and the car fired up like there was no problem. I let the engire run a few minutes to charge the battery.
Went back two days later (yesterday) and again the car would not start.
Considering that this problem comes and goes, where would you look first? The distributor? The alternator?
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
If the car is still in the wet garage the moisture could have collected in the cap again,check the points for moisture. Check to be sure the coil is firing by removing the coil wire from the distributor and holding the end about 1/2" from one of the shield brackets and have some one crank the engine and watch for a spark.
Also, checked the distributor but saw no sign of moisure.
By the way, the distributor contains an after-market ignition module. Mallory is the brand name - the kind with three wires coming out of it: red wire goes to positive terminal on coil; green wire goes to negative terminal on coil; brown wire goes to engine ground.
I want to thank everyone who's been offering suggestions. As you can tell, I don't know this stuff well at all, so help is appreciated.
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
Got my hands on a diagnostic tool - which indicates a problem with either the Mallory Unilite Ignition module or the distributor pickup.
I saw a message board for Ford Mustangs where people were complaining that the Mallory module was prone to giving out very suddenly. Has anybody encountered this with a Corvette?
I saw a message board for Ford Mustangs where people were complaining that the Mallory module was prone to giving out very suddenly. Has anybody encountered this with a Corvette?
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
Just to wrap this up in case anybody else come along reading this thread and wondering what the solution was...
When I opened the distributor, the old Malory Unilite ignition module was physically broken - the top half dangling by the wires.
I replaced it with a new Mallory E Spark and the car started immediately.
I still have some problem with the battery not having enough juice to start the car, but that's another thread.
When I opened the distributor, the old Malory Unilite ignition module was physically broken - the top half dangling by the wires.
I replaced it with a new Mallory E Spark and the car started immediately.
I still have some problem with the battery not having enough juice to start the car, but that's another thread.
