My 67 died in a shopping mall and it came home on an AAA flatbed yesterday. I had just filled the tank at a Shell station, so there's gas, and I can see it getting to the carb when I crank the starter and pump the gas pedal. The main symptom is that when I crank the engine and ground the coil-to-distributor cable against the valve cover, no spark is visible at the grounding point. The tow truck driver also observed this. The 3-year-old Die Hard battery was in good condition, until it got run down trying to start the car, and my emergency portable battery/cables unit now still is strong. I took my kill switch out of the picture so that it no longer is connected to the ignition circuit. I bought a new coil at Kragen's and installed it, but the car still won't start. So, what could be the cause of no electricity coming out of the coil?

I'm off to buy a battery charger now…..

Louie

 

I assume you have a 12V test light. If not, get one, as they are essential to vintage Corvette ownership.

With the ignition switch "on", check the top wire at the ballast resistor to see if you have voltage, and also at the bottom. You will get direct voltage from the solenoid when cranking at the bottom. If you don't have voltage there, go back to the ignition switch. The three likely culprits here are the ignition switch, the ballast resistor (though from what you describe, I don't think so), and the connections at the solenoid or the solenoid itself. Work backwards on the system until you find voltage and then see why it isn't making it to the coil and distributor.

 

Louie go and get yourself one of the testors that plug in between your spark plug wire to your spark plug. You can leave it on until you have fixed your problem. It is alot easier to see if you have any spark with that little tool. Most part stores have them in stock. There is a light bulb that lights up when cranking your motor showing you if you have any spark. This way you won't get jolted from holding the plug wire to a ground. Been there done that. Harbor Freight has these testors really cheap right now. Here is a link: http://www.harborfreight.com/cpi/cta...emnumber=36258

This tool is a lifesaver from anything from your lawn mower to your car. I keep one in the glove compartment on most of my cars just in case.

Fred

 

All good things to check. When I have one of these, I start at the coil and test for voltage at the + terminal. No matter whether you have points, TI, or aftermarket ignition, you need voltage (12 VDC) at the + terminal. This splits the search from supplying current or switching it.

 

The battery got recharged.
I confess to not having a test light (but will get one tomorrow!), so I used a handheld multimeter instead. With the ignition switched to "On," there is voltage at the top and at the bottom of the ballast resistor, and also at the coil's (+) terminal.

The engine cranks vigorously, so the solenoid works. If I have the headlights on and crank the engine, the headlights of course get a bit dimmer but do not go out or even almost out. After cranking, residual gas is obvious in the primary venturi, so I assume the fuel pump works. When I crank the engine, there's still no spark where I ground the cable from the top of the coil to the valve cover. Since my multimeter says that there's voltage at the coil (+) terminal, do these symptoms suggest that this new coil (I bought it yesterday at Kragen's Auto) is bad? Do all these symptoms suggest that the ignition switch is functioning properly (it seems so to me, but….)?

Fred -- I'll get one of those spark plug tester lights tomorrow.

Thanks for all the idea, guys, I need more ideas than I can come up with myself.

Louie

 

Louie: From the old start it without a key days, have you tried a hot wire from the positive battery terminal to the hot side of the coil? This bypasses the ballast resistor and you can, I believe, eliminate it from the circuit for test purposes. Hard on points.

Make sure you have an alligator clip on the battery to hot coil supply so that you can shut the car off by pulling the battery lead off, presuming it starts.

You may have obtained a defective coil but it is not the most common of things. Ballast resistor failure would be more likely.

Have you looked inside the distributor and checked the rotor and the cap out yet? Everything OK there?

Grasping at straws now.

With cap off the distributor and someone cranking the engine, is the distributor shaft turning? Broken drive gear shear pin?

Good Luck Tell us how it turns out.

Rich

 

The car just started. Here's how: After sending my latest reply, I remembered that I have an extra coil in my cross-country driving supplies (also an alternator, water pump, fuel pump, carb kit, etc.). I swapped it in and the car started. Meaning the #*@! new coil from Kragen's is a POS.

So, thanks to you guys in Alabama, New Jersey and Iowa for suggesting various lines of inquiry that ultimately led me to question the reliability of the new coil out here in California. Without your suggestions I would still be floundering, since electricity is not at all my strong point.

I'll have a 12V test light and spark plug light tomorrow, so overall I've gained from this experience.

Thanks again!

Louie

 

OK We're narrowing things down. The problem is coil/distributor related.

To test the coil, take loose the lead from the - side of the coil. Attach a wire to the terminal. Pull the lead from the coil to distributor out of the distributor and put an old spark plug on the end and ground it to the motor. Turn the ignition switch to the on position. Tap the wire against the engine block at a good ground. This should cause the spark plug to fire a clean blue spark. If it does, we go on, if not the problem is coil or ground related. If it doesn't spark, check ground for the coil before deeming it bad. Use your multimeter and check voltage from the + terminal (with the switch on again of course) to the case of the coil. Compare this measurement to testing to the battery - terminal. If the case is properly grounded, these should be almost the same readings.

If the coil tests ok, next is the distributor. You did not mention if you have points, TI, or aftermarket ignition. I assume you have points. To test a point distributor, restore the connections earlier removed. Remove the distributor cap and rotor. First test is a simple visual test. Crank the engine while watching the points. If you see a blue spark at the points, the condenser is bad. If the points do not open, something either broke or adjustment moved. If nothing is visually wrong, the next is to verify that the points are properly grounded through the distributor and block. Measure the voltage at the coil to the fixed side of the points. Open the points. Full 12 volts should be present. If not, check the lead wire and further check for good grounds. Next is to inspect the points themselves. If you clean or adjust them, you will need to reset them. I have a specialized point file with a captive points holder for dressing points. Some people use emmery cloth sucessfully. Some just use folds of paper. Whichever you have available, with the points closed, using the spring tension of the points only, wipe your tool of choice between the points to clean them. This will slightly alter the position of the distributor shaft where the points open, changing the dwell angle and changing timing. Any time you work on points, the dwell angle must be reset. Some use feeler gauges to establish dwell, I prefer to use a dwell meter. You get a more accurate reading and setting that way. Be aware that a 1 degree change in dwell results in a 1 degree change in timing.

Give these a shot and let us know what you find.

P.S. Well it looks like you found your problem and posted it while I was writing this. Good job!

 

Have you checked the points:
Adjustment slipped? Not opening? Not closing? Broken arm?
Contact point(s) broken (arc'd) off?
Big glob of lube/dirt stuck where it shouldn't be?

Distributor cap contacts glazed over?
Rotor worn down?

 

Louie,

I read through and noticed that you did get it started, check the connection to the coil also though, you might have had it grounding out through the ignition shielding if they were touching.

Glad you got it going,

Tom M

 

rgs - Thanks for your time in putting down your ideas. I appreciate it when a knowledgeable person shares.

The car problem might not be fixed. Once I got the car started I left it on for less than a minute, shut it off, then went into the house to let you know about this. When I returned to the garage, the car wouldn't start! Same symptoms! Why in heck would *good* coil fail after one start????? I can't believe it and can't face this problem any more tonight, so will leave it for tomorrow.

Louie

 

That would lead one to believe that something is heating up and failing open, ie coil, ballast resistor, or possibly condenser.

 

Now that you found the Kragen coil was a POS, I would still give it a major electrical tune up. points, condensor, cap and rotor. Then set timing and check vacumn advance. Finally have the carb adjusted using a gas analyser. "CORVETTE ENTHUSIST" magazine had a great story on power tuning 63-67 cars for today's gasolines.

 

Maybe the second coil is bad too; I don't recall where I bought it over a year ago. Tomorrow I'll try the coil testing mentioned above by rgs.

BTW the distributor has an SE breakerless system in it, from Lectric Limited. Dave Fiedler rebuilt the distributor and installed that item; everything but the dist. housing was replaced a couple of years ago, even the main shaft. The car ran like a top before it died.....famous last words, I know, I know.

Jim, I'll get the carb as good as possible, but don't own a gas analyzer. Are those cheap enough to buy these days ---prob. not --- or are you suggesting I go to a shop/station with one?

I'll try borrowing a coil that is known to be good tomorrow. If that works, I'll find a high quality one somewhere.

Louie

 

I would bet it's the breakerless ignition going bad.

 

Yep, that is a critical piece of info. Before you do anything else, take the AM ignition out and put the points back in. Real good probability that will solve your problem.

 

rgs -- I just performed the test you describe and got a clean blue spark (although a small one) from the spark plug to the engine ground, so the coil seems to be good and the distributor seems to be the problem. You clearly described how to test a points-type distributor, but I have the SE breakerless unit in my 327/350. I looked and nothing within the dist. cap is broken or worn. Is there any way to test this electronic ignition to say whether it is functioning as designed or not? Is the simplest thing at this point to install the stock points, rotor and condenser?

Louie

 

Louie,
Id swap the parts out if you have to have her running pronto, but Id contact Lectric Limited and the guy who did the assembly. IMHO no one wll help you through this bug like they can (and should).

 

If everything up to the coil is working the only remaining component is the distributor. The only ignition components within the distributor are the rotor (rarely ever goes bad on a points type distributor) and points/breakerless ignition. You can check the gap on the breakerless ignition to see if it is correct but the only other way to check it is to swap it with a set of points or another breakerless ignition unit.

One other possiblity is that the wire that grounds the points plate within the distributor is broken and therefore not providing a consistent ground. This could possibly create an intermittent problem like you have described.

 

Louie you may have an intermitent problem with your breakerless ignition. Being in the auto parts business I have seen this happen alot over the years with electronic ignition modules. They do go bad. I know I have sold plenty of new modules over the years. Sometimes they work when they are cold but once the car runs for awhile and you shut it down the car won't start again (NO SPARK) until everything cools down. I would contact who ever made the aftermarket breakerless ignition system you have in your car to see what they have to say. On GM cars from 75' on up until GM went with distributorless ignition all one basically had to do was just replace the module in the distributor, a pretty easy task especially on a C-3 Corvette. Your aftermarket system is made differently. You can't just walk over to your local parts store and pick up a module. That is why I still have points in both my C-2 and C-3. My streetrod has a 1975 type GM distributor in it so picking up a Delco D1906 module although I have them in stock, they could be picked up just about anywhere if I broke down if it was needed to fix my problem. Problem with this aftermarket stuff is you can only get it from that particular part maker or who ever carries their ignition product meaning you may have to wait for the part to be sent out to you.