Corvette will not start
Thread Starter
Instructor
Joined: Jan 2017
Posts: 175
Likes: 14
Corvette will not start
Hello all.
I drove my corvette (74, l-48) a few days ago and it started up and drove well. I tried to drive it again this morning and it would not start. Some helpful info below:
1. Starter, New HEI distributor, spark plugs were installed 7 years ago.
2. Carb was rebuilt at that time.
SYMPTOMS:
1. Car is cranking over fine, carb is receiving fuel when I pump it. Battery is good so I assume my fuel pump/carb/starter is working as it should.
1. I did suffer from some vacuum issues in which a hose popped off the front of the carb but I re-attached it months ago and it hasn’t moved or had any issues since.
2. I think it could be spark related.
3. I have no way of testing my fuel pump right now, only way I think it’s working is that I smell fuel after one or two pumps this morning.
Questions:
1. Before throwing money into it (coils, ignition module, cap etc) how do I test my distributor to see what parts are bad?
2. Can someone add a couple photos of a carbon fouled and a fuel fouled plugs for me? I’ll pull those soon.
(I have no tools right now to pull them)
I drove my corvette (74, l-48) a few days ago and it started up and drove well. I tried to drive it again this morning and it would not start. Some helpful info below:
1. Starter, New HEI distributor, spark plugs were installed 7 years ago.
2. Carb was rebuilt at that time.
SYMPTOMS:
1. Car is cranking over fine, carb is receiving fuel when I pump it. Battery is good so I assume my fuel pump/carb/starter is working as it should.
1. I did suffer from some vacuum issues in which a hose popped off the front of the carb but I re-attached it months ago and it hasn’t moved or had any issues since.
2. I think it could be spark related.
3. I have no way of testing my fuel pump right now, only way I think it’s working is that I smell fuel after one or two pumps this morning.
Questions:
1. Before throwing money into it (coils, ignition module, cap etc) how do I test my distributor to see what parts are bad?
2. Can someone add a couple photos of a carbon fouled and a fuel fouled plugs for me? I’ll pull those soon.
(I have no tools right now to pull them)
Race Director
Joined: Mar 2017
Posts: 11,947
Likes: 4,506
From: Virginia
If you want to throw a small amount of money at the problem, you could try a spark tester, like this Lisle unit.
Or you could pull a plug wire, ground a spare spark plug to the block (alligator clips, or clamp), and look for spark in the dark.
Or your timing light will trigger if you have spark (but might also trigger if you have weak spark).
You could also try starter fluid, to confirm that your problem is spark (or compression).
Or you could pull a plug wire, ground a spare spark plug to the block (alligator clips, or clamp), and look for spark in the dark.
Or your timing light will trigger if you have spark (but might also trigger if you have weak spark).
You could also try starter fluid, to confirm that your problem is spark (or compression).
Thread Starter
Instructor
Joined: Jan 2017
Posts: 175
Likes: 14
Thank you for the replies. It must of been a bug or not enough sweet talking to it…….lol…
I let it sit for about an hour and tried again and it started, backfired out the exhaust…..but started lol. Drove it around for an hour no issues.
think a carb rebuild is in the near future.
I let it sit for about an hour and tried again and it started, backfired out the exhaust…..but started lol. Drove it around for an hour no issues.
think a carb rebuild is in the near future.
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I'm really not certain why you think a carburetor rebuild is in order if it runs just fine.
Perhaps you just flooded it! This is just driver error and happened back in the day when we all drove Carbureted cars. May wish to remove the airfilter lid and observe the operation of the choke butterfly. Make certain all that is working. And if you flood it again. Jam something in there to hold the choke butterfly open. Hold the pedal to the floor and crank the engine. When it fires remove the wedge from the choke. Gezz, when we were kids this was normal in cold weather.
In the mean time you may wish to invest in some basic tools so next time she plays up you will be a little more prepared. A spark tester is a good thing to have. Tools to remove the spark plugs and a basic socket and wrench set should be must haves.
Perhaps you just flooded it! This is just driver error and happened back in the day when we all drove Carbureted cars. May wish to remove the airfilter lid and observe the operation of the choke butterfly. Make certain all that is working. And if you flood it again. Jam something in there to hold the choke butterfly open. Hold the pedal to the floor and crank the engine. When it fires remove the wedge from the choke. Gezz, when we were kids this was normal in cold weather.
In the mean time you may wish to invest in some basic tools so next time she plays up you will be a little more prepared. A spark tester is a good thing to have. Tools to remove the spark plugs and a basic socket and wrench set should be must haves.
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
I agree that it sounds like it was flooded. Have you looked at the owner's manual GM's engine start procedure? It's definitely not like today's modern fuelies.
That's easy to describe without pics (but a simple google search will show them): fuel or oil fouled plugs will get have a wet appearance and you'll be able to wipe it off on a paper towel. If the condition has been going for a while, you'll get heavy soot and crusty carbon deposits that are baked on to the surfaces, the white of the insulator will be black. These deposits won't wipe off.
A tuned, clean running engine with properly chosen plugs will only put minimal deposits (light-colored) on the plugs and the color of the insulators will turn a light tan color. For standard electrode plugs, the end of the electrodes (where the spark jumps) should retain their sharp edges and not be rounded off to any degree. There will be some normal variation between all 8 plugs in every engine just because each cylinder does not receive the same fuel charge, experience the same heat environment, nor have identical piston & rings and intake & exhaust valves and seats.
A tuned, clean running engine with properly chosen plugs will only put minimal deposits (light-colored) on the plugs and the color of the insulators will turn a light tan color. For standard electrode plugs, the end of the electrodes (where the spark jumps) should retain their sharp edges and not be rounded off to any degree. There will be some normal variation between all 8 plugs in every engine just because each cylinder does not receive the same fuel charge, experience the same heat environment, nor have identical piston & rings and intake & exhaust valves and seats.
