63 327/300 shuts off suddenly - help me diagnose

[Frederick W.]

Have had the car for about 4 years and has run perfectly. Went to start it today after sitting about a month (typical for me). Was hard to get it to fire off and when it did it fired hard and immediately stopped. Multiple attempts same, fires off with variably long cranking times, revs up and immediately shuts off. A couple of times I was able to keep it running, one time for about 2 minutes. During that time it ran smoothly and fine, and I was letting it idle. Then abruptly shut off again and back to same behavior.

I checked the carb and good squirts from the accelerator pump (Carter AFB). I still suspected fuel problem. I took the carb off and removed the top/bowl cover. Bowls were full of decent looking fuel (noticed the SS baffle/gasket was corroded through to the heat slot below in a couple areas, ordered a new baffle). I ran a hose from the fuel line (after the filter) to a jar and cranked it for 15 seconds to check fuel pump output. Got about a pint of decent looking fuel.

So now I'm suspecting some kind of intermittent or incomplete spark problem. I think I'll pull the plugs to look at them and check the points.

Thoughts?

Fred

[Edward J.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Fred, Try a test light to see if there's power at the ballast res. with key on,(bottom of pink wire) if so try using a jumper across the ballast and check to see if it starts and runs.

[Dave S.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Fred, Try a test light to see if there's power at the ballast res. with key on,(bottom of pink wire) if so try using a jumper across the ballast and check to see if it starts and runs.

In addition to Ed's suggestion you may have a bad ignition coil. Generally they pass a continuity test but when they heat up they fail.

[Leif A.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Also, depending on the age and condition of your wiring harness, check the always problematic bulkhead connectors for connectivity and lack of corrosion.

[Ed S.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Also, depending on the age and condition of your wiring harness, check the always problematic bulkhead connectors for connectivity and lack of corrosion.

Leif, your recommendation to check the "bulkhead connectors" is one that appears frequently. Not to imply that they are the source of recurring problems. That said, may I ask, exactly what is a "bulkhead connector"? Can you, or anyone post a pic or describe a bulkhead connector that one would find on a C2 Corvette. I have a general idea of what a bulkhead is, and I certainly know what a connector is - but it sounds like you and others that refer to these have a particular set of gizmos in mind.

[Larry M.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Leif, your recommendation to check the "bulkhead connectors" is one that appears frequently. Not to imply that they are the source of recurring problems. That said, may I ask, exactly what is a "bulkhead connector"? Can you, or anyone post a pic or describe a bulkhead connector that one would find on a C2 Corvette. I have a general idea of what a bulkhead is, and I certainly know what a connector is - but it sounds like you and others that refer to these have a particular set of gizmos in mind.

The "bulkhead" connectors are a set of two connector blocks located directly below the master cylinder on the C2 cars. Each connector block has 8 separate circuits. You can't miss them, as just about all your electrical wires from the cabin to the engine bay run thru these blocks. One of these separate circuits contains a 10-12 gage red wire that supplies the juice to just about everything with power. That is the wire Leif mentions.

The blocks are subject to corrosion over the years. They are also brittle and can be easily unhooked from vibration if not hooked up correctly. You may want to use a hair drier or heat gun to warm the wires prior to disconnecting the blocks.........especially during cold/winter weather.

Larry

[Leif A.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Leif, your recommendation to check the "bulkhead connectors" is one that appears frequently. Not to imply that they are the source of recurring problems. That said, may I ask, exactly what is a "bulkhead connector"? Can you, or anyone post a pic or describe a bulkhead connector that one would find on a C2 Corvette. I have a general idea of what a bulkhead is, and I certainly know what a connector is - but it sounds like you and others that refer to these have a particular set of gizmos in mind.

Ed,

Approximately 6" directly underneath the driver's side female hood latch.

[Leif A.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Leif, your recommendation to check the "bulkhead connectors" is one that appears frequently. Not to imply that they are the source of recurring problems. That said, may I ask, exactly what is a "bulkhead connector"? Can you, or anyone post a pic or describe a bulkhead connector that one would find on a C2 Corvette. I have a general idea of what a bulkhead is, and I certainly know what a connector is - but it sounds like you and others that refer to these have a particular set of gizmos in mind.

Ed,

Approximately 6" directly underneath the driver's side female hood latch.

[Donald H.]

Re: 63 327/300 shuts off suddenly - help me diagnose

And even when you think you have cleaned the corrosion and have good connections with the firewall connections, keep checking. I had a problem with a battery meter that stopped working, and thought I had them clean. Link below, it was those connection!

https://www.forums.ncrs.org/showthre...hlight=battery

[Frederick W.]

Re: 63 327/300 shuts off suddenly - help me diagnose

I'm waiting for the stainless baffle to arrive to put the carb back on. Then I'll check the ballast resistor and coil. It has a replacement wiring harness from a previous owner , probably 10 years ago. Hope that means the firewall connections are good, but I'll check that too. Finally, I'll also be looking at the ignition switch for a loose connection.
Any other thoughts, let me know. I'll follow up when I can.

[Ed S.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Ed,

Approximately 6" directly underneath the driver's side female hood latch.

Leif,
Thanks - I assume the bulkhead connector is directly opposite of the fuse panel that is under the instrument panel on the driver's side.

On an un-related issue, in the pic you posted, is that a battery terminal in the upper right corner of the pic? If yes, then I assume that the pic is not one of a C2 -- just curious. Thanks again.

[Larry M.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Leif,
Thanks - I assume the bulkhead connector is directly opposite of the fuse panel that is under the instrument panel on the driver's side.

On an un-related issue, in the pic you posted, is that a battery terminal in the upper right corner of the pic? If yes, then I assume that the pic is not one of a C2 -- just curious. Thanks again.

It is a factory air car.

LARRY

[Leif A.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Leif,
Thanks - I assume the bulkhead connector is directly opposite of the fuse panel that is under the instrument panel on the driver's side.

On an un-related issue, in the pic you posted, is that a battery terminal in the upper right corner of the pic? If yes, then I assume that the pic is not one of a C2 -- just curious. Thanks again.

Ed,
Yes, the bulkhead (firewall) connector corresponds to the fuse panel on the interior of the firewall.
And, as Larry answered for me, my car is a '67 factory A/C car...battery located on the driver's side with this application.

[Mark E.]

Re: 63 327/300 shuts off suddenly - help me diagnose

Check that all electrical connections in and around the distributor are clean, dry and tight. This includes:
- Primary connections at coil, ground wire inside distributor (its terminal under breaker plate is notorious for coming loose), connections to points
- Secondary connections at each end of the spark plug cables. Check for carbon tracks and cracks inside the cap.
- Terminals on underside of the cap, and the rotor itself

Check integrity of distributor coil and ground wires. Look for loose terminals, cracked insulation.

Visually check the contact points and condenser then test them electrically. Make sure dwell is stable at different engine speeds. I've seen points burned out because too much WD40 was sprayed on them after the engine was steam cleaned. Make sure they're clean, dry, smooth and shiny.

You might try just replacing the coil, cap, rotor, points and condenser. They're relatively cheap and easy to R/R. This will help eliminate possible causes as you troubleshoot.

[Frederick W.]

Re: 63 327/300 shuts off suddenly - help me diagnose

I got my carb baffle and replaced the carb, and turned my attention to the ignition.
Short story: the car starts and runs fine with a jumper from the battery to the + side of the coil.
When I turn on the ignition switch, and use a test light, there is no current to the coil or to the ballast resistor (either terminal).
So I suspect the problem is a short between the ignition switch and the ballast resistor. Other than the ignition switch itself, is there another source of shorting to explain my issue?

Fred