[1_Wild_Cat]

Hi John — I’m caught on the fact that your changing the condenser fixed the issue for a bit.

The situation reminds me something that happened with my 70 Buick years ago. The problem turned out to be a short in the wire between the coil and the distributor. It was shorting to the distributor housing.

The symptoms were similar to yours - when the car warmed up it would sometimes stall like the ignition was shut off. Sometimes it would restart right away sometimes not. The main difference was that it never showed a rough idle/partial stall. But I think a similar problem could present that way.

The test I used to isolate the issue was installing a jumper wire between the distributor and the coil. I routed it out to the coil from under the cap through the dwell door in the cap.

Worth thinking about…

[John V.]

Good suggestions.

Don't think the '64 has a tank vent but uses a vented gas cap.

I've thought about the cap being bad. Is there an easy way to check if the cap is venting? I have never had it "whoosh" when removing it if that is any indication.

I know it is wrong to jump to conclusions but since it runs very well from a cold start and for quite some distance after, it is hard for me to imagine that I have a fuel flow or spark problem.

But mix in high underhood temps and the symptoms begin.

I plan to start by checking to see if the Heat Riser Valve thermo spring is gone.

Tom, the pic you posted of the HRV is strange. What is that off of? I'm sure you know on the '64 the HRV is part of the manifold itself, the one you posted looks like it can be separately replaced?

But main question, if the thermo spring is gone, do they sell just the spring? Would NAPA carry them?

[Tom Vaught]

It was just to show how the spring coil wrap changes to open and close the valve.

Agree, on our vehicles it is part of the manifold. I wired mine open early on and then went to Headers, the manifolds were lost in the shuffle.

Closest to stock after that, was a set of 67 RA manifolds that I sold to a friend, (having never installed them on my engine).

Tom V.

[John V.]

I'm back. Haven't run the car since I last posted. Since then I've discovered that both springs are still on the HRV. There is hardly any spring tension on the weight end. And since I haven't run it, I don't know if the thermo spring is opening the flapper valve. But I'm doubting that is my problem.

I pulled 3 of the plugs. I'm not an expert plug reader but they weren't fouled and tan/brown in color. My impression was the plugs are pointing in another direction.

Recapping, I replaced the distributor condenser after a no start condition last summer. Engine immediately started and idled good for a minute or so.

Couple weeks later I took it for a first drive. Ran good for about an hour. Then the engine began stumbling badly at idle. Parked it for 2 hours. Restarted and drove an hour home in cooler weather, made it home without any really bad stumbling.

For reasons having to do with non-car issues, the GTO has sat since, no attempt to start until yesterday. I planned to start it up and check the operation of the HRV. I put a trickle charger on the battery a couple days earlier.

But after cranking the engine for an extended period, I'm back to a no start condition. Not even a cough.

I have fuel to the carb. Based on my prior experience, I will replace the condenser again. Based on widespread internet belief that new condensers are junk and thinking I'm now twice bit, I have ordered an NOS Delco condenser.

I won't know until I install the replacement condenser but assuming it fires right up, I will have confirmed a bad condenser.

What I am hopeful for is that the Delco condenser will be more of a permanent fix. But it doesn't give me a lot of confidence to just believe that the previous 2 condensers went bad because of poor quality which can only be proven if the Delco condenser doesn't crap out over the next 5-10 years.

The engine has always started easily and idled and run good at least for a period of time. When it began stumbling and then finally a no start condition, a new condenser had it starting easily and idling good again at least for a very short time. And now I have another no start condition. I'm assuming a new condenser will have it starting easily again.

Aside from poor quality, the only thing I think can kill the condenser would be over-voltage. Can anybody take a stab at multimeter checks that I should do to determine that I don't have an over-voltage condition that is killing the condenser?

1. How do I check the Resistance wire and what value should I see?
2. How do I check the voltage to the condenser and what value should I see?
3. Do I need to worry about the voltage regulator?
4. If all of the above checks good, is there anything else that could cause the death of the condenser and how can I make other checks?
5. Could using a trickle charger affect the condenser?

[b-man]

Moving to the Street forum for more exposure and perhaps a solution.

This isn’t just a 1964 issue.

[AG]

You have one wire going to your coil which is black-pink. This has a connection in the harness to two other wires, a black-yellow and a white-orange-purple which you can't access without undoing the tape over the wiring, it's a soldered junction. I think the black-yellow wire is the run wire which should be the resistance wire. You can check voltage to the coil with the key in the run position without starting it and that should be the resisted voltage, probably around 9-10 volts. Cranking you should see a full 12.4 volts. If you get it running check voltage at the battery to make sure the regulator is working and if all electrical checks out start looking somewhere else. Start with the basics and make sure your points, cap, rotor, wires, spark plugs and carb are all good.

[Bill Hanlon]

Originally Posted by AG

You can check voltage to the coil with the key in the run position without starting it and that should be the resisted voltage, probably around 9-10 volts.

Testing as above depends on whether the points are open or closed when you take the measurement. If the points are open, voltage should read battery voltage. If closed, somewhere around 8-9 volts.

If the engine is running (yours is not) the voltage will be varying from around 8 volts to battery voltage very rapidly. An old fashioned analog volt meter sort of averages these high speed variations, so you'd probably see around 10 volts or so. A digital meter would most likely be bouncing around between the lowest and highest readings.

[25stevem]

The strangest dying and no start condition I have ever had was with the original distributor wire that runs under the beaker plate to the points having no insulation left due to dry rot.

When the vacuum advanced pulled the plate around or the car hit a big enough bump in the road it shorted out that wire which signaled the spark coil that the points where not opening.

After enough times of that taking place the wire was just in a position where it was touching metal and shorted all the time.

[johnta1]

Check what Steve said, but I would put a new set of points in it.

[John V.]

Okay, here is the troubleshooting I was able to accomplish today, won't have the new condenser for a few more days.

Checked battery voltage at battery terminals. 12.72V

Then for yucks, I tried cranking it. Only thing I did different vs. Saturday was I didn't touch the gas pedal. Normally, I depress it once to set the choke which I did Sat but not today. The choke had remained set since it never started. Surprisingly, the engine coughed but didn't start. I did that 2 or 3 times and I quit. Left the ignition in On/Run position.

I did not go looking for the Resistance wire but for '64 it is Orange/White/Purple according to the schematic, connected to Ignition 1.

Ignition 2 (Start) position is a Pink/Double Black Stripe (per SCN revision, Shop Manual showed it as Pink/Dark Blue/Black).

My underdash wiring is OE including the fuse block.

The engine side wiring is reproduction, including the wrong color Connectors.

Checked for voltage at the positive side of the coil where the Pink/Black wire is connected. Ground was the convenient ground strap to the firewall just aft of the coil.

I got 7.15V.

According to the '64 Tempest Shop Manual, I should get 5V-7V with the points closed. And see Battery Voltage with the points open.

I bumped the starter several times hoping to get the points opened to see Battery Voltage but always got 7.10V to 7.15V.

I then tried to crank the engine again. Still didn't touch the gas pedal but cranked it in earnest. I got it to cough a couple times as if it might start while I held the key in Start position for a prolonged time it but still didn't fire. Did that 2-3 times, same each time.

Keep in mind, this engine has about 600 miles on it since rebuild and always fired up easily when cold (like only needed to hold the key in Start for a second or so) except for the no start event last summer. After the condenser replacement, it also fired easily as long as it had been run within the previous day or 2. If it sat for a week, I would crank for maybe 10 secs to get fuel to the carb. Then next twist of the key it would fire right up.

So with fuel at the carb, easy starting has been the norm.

After the attempt to get it started today, I rechecked the voltage at the coil positive terminal.

This time I got 7.35V.

I bumped it again and rechecked, same 7.35V. I quit at that point to post this.

Perhaps it is noteworthy that I never got it to show Battery Voltage. Could mean the points are stuck closed.

Not sure what would happen if the points were stuck closed, the fact that the engine coughed a bit while cranking surely means I'm getting at least some spark. Don't know if that would be possible with the points stuck closed?

I'll take a look at the points when I pull the cap to replace the condenser, both to see if the points are opening and to see the condition. I don't really remember how they looked when I replaced the condenser last time but since I didn't replace them then, I'm sure they looked pretty brand new and only driven 100 miles since.

Even though the Shop Manual suggests several possible issues for a reading over 7V, I'm thinking the readings I'm getting are "normal" enough to indicate the Resistance wire is functioning correctly.

I think the Battery Voltage is a tad high but explainable by the fact that I trickle charged it and have done nothing except tried to crank it several times on Saturday and a few more times today. Anybody see a problem with the Battery Voltage?

Except for the uncertainty of the points opening, anybody see anything that would be killing the condenser?

The Shop Manual suggests a handful of other voltage tests I could be checking. Generally, they require the points to be closed so I'll need to see what the points are doing before I consider making additional checks.

Curious if anybody wants to interpret what I've seen so far.

[Bill Hanlon]

Could be stuck closed or grounded in some way. Pull the distributor cap, open the points with a tool of some kind and put a business card or some other insulating material between the points. Turn the key back on. Coil + SHOULD be at battery voltage. Turn the key back off.

If not, remove the coil - wire that goes to the distributor. Turn the key on. Coil + SHOULD be at battery voltage. If not, what voltage is on coil - ?

Turn the key back off. Remove the business card.

More troubleshooting once you answer these questions.

[John V.]

Bill, thanks for the suggestions, I'll make those checks tomorrow.

I understand the first check, same as if the points were open, so should see Battery Voltage.

Pulling the cap will allow me to see if the points are in fact opening. So I'll check that and look at the points for pitting.

The 2nd check with the coil wire to the distributor disconnected, I want to be sure what you are saying.

Where am I connecting my voltmeter? Am I checking each coil terminal separately?

By connecting my voltmeter to each terminal and ground, I should get Battery Voltage at the positive coil terminal and same when checking the other coil terminal.

If I have that straight and if for some reason I don't get Battery Voltage at the positive coil terminal, you'd like to know what voltage I get at the other coil terminal.

If this isn't right, please straighten me out. Otherwise I'll proceed to check the voltages and report back.

I'll put a business card between the points but I'll also see if the points are opening on the cam.

More to follow!

Oh, one more thing, I have the factory '64 tach. I haven't paid attention, but I believe it is hooked up to the coil on the other coil terminal (not the positive coil terminal where the Pink/Black is connected). I will confirm that when I do the additional checks.

Should I disconnect the Tach wire when I disconnect the coil to distributor wire? Could the Tach have anything to do with the Condenser failure? The Tach seems to work fine but since it is connected (I think) to the same coil terminal as the Condenser in the circuit, I figure it is worth mentioning.

[Bill Hanlon]

Originally Posted by John V.

The 2nd check with the coil wire to the distributor disconnected, I want to be sure what you are saying.

Where am I connecting my voltmeter? Am I checking each coil terminal separately?

By connecting my voltmeter to each terminal and ground, I should get Battery Voltage at the positive coil terminal and same when checking the other coil terminal.

If I have that straight and if for some reason I don't get Battery Voltage at the positive coil terminal, you'd like to know what voltage I get at the other coil terminal.

If this isn't right, please straighten me out. Otherwise I'll proceed to check the voltages and report back.

You have it right. Check both coil + and -.

Oh, one more thing, I have the factory '64 tach. I haven't paid attention, but I believe it is hooked up to the coil on the other coil terminal (not the positive coil terminal where the Pink/Black is connected). I will confirm that when I do the additional checks.

Should I disconnect the Tach wire when I disconnect the coil to distributor wire? Could the Tach have anything to do with the Condenser failure? The Tach seems to work fine but since it is connected (I think) to the same coil terminal as the Condenser in the circuit, I figure it is worth mentioning.

Do the test on both coil terminals with the tach attached to the coil - terminal and then do it again with the tach disconnected. Report all 4 results.

[John V.]

First thing, I checked the Battery Voltage with the key out. Got 12.73V

Checked the Coil Positive terminal with key On. Got 7.09V

Removed the cap, took some pix. The original '64 GTO Distributor was restored/set-up by a pro. I don't know what all was done to recondition it but I assume all replaceable worn parts were replaced. The pix would show the Distributor and all components and wiring looking pretty much "as new". Only driven about 600 miles, actually closer to 700 since the speedo driven gear is incorrect for the 3.36 axle ratio.

I checked the wire from the coil to the distributor, no damage that I could detect. The Tach is hooked up to the other coil terminal as expected and includes an in-line fuse holder a few inches from the coil connection.

I chose not to disconnect the coil to distributor wire or Tach wire after the initial check today, I will do so if you think it would provide useful data.

After removing the cap, I saw the points were closed as expected. I tried bumping the starter again to open the points but not easy working alone so gave up after 3 or 4 bumps.

I slipped a piece of a business card between the points, they opened easy enough, no indication they were "welded" closed. I couldn't check closely for pitting, but honestly, the point set looks about brand new.

Turned the key On and checked at the positive coil terminal. 12.39V.

Then checked at the other coil terminal (with wires still attached) and got 12.36V.

Just for yucks, I rechecked the Battery Voltage with the key still On. 12.50V.

I rechecked each coil terminal again, the readings varied about 0.01-0.02 each time, 12.39V was the highest at the positive terminal.

The other terminal was consistently 0.02-0.03 lower than the positive terminal.

I checked the Battery Voltage a couple more times, 12.60V with key out, 12.52V with key On.

I concluded that the readings were normal, pulled the biz card and the key out.

Like I said, if the readings with the coil to distributor and tach wires removed would be useful, I can do that. I tend to be clumsy with small hardware so rather than lose the attaching nut, I figured I would report these nos. before proceeding.

Condenser is supposed to arrive on Monday by USPS so I have time to check anything else that might be a cause of Condenser failure. I'm hoping that poor design and poor material quality are the reason for the failures but I appreciate the help in trying to find another root cause.

And there is always the chance I am barking up the wrong tree assuming the Condenser has failed because that seemed to be the culprit last year.

[Bill Hanlon]

Originally Posted by John V.

The Tach is hooked up to the other coil terminal as expected and includes an in-line fuse holder a few inches from the coil connection.

I chose not to disconnect the coil to distributor wire or Tach wire after the initial check today, I will do so if you think it would provide useful data.

What is the "other coil terminal" that you have the "Tach hooked up to"? Coil + or coil - ?

How many wires at the tach? Depending on tach design, there could be as few as 1 (should connect to coil - ) or as many as 4 (power, coil -, ground and light).

Sounds like no shorts or opens in the coil to points portion of the circuit.

If you have a dwell meter hook it up and crank the engine. Should read near 30 degrees.

[Sirrotica]

John, if you mentioned it, I didn't find it, have you verified the points are opening?

Points put in with no lube on the rubbing block can wear the block down in 600 miles, causing the points to not open, and the loss of spark.

Just something I have run into before when someone either doesn't know enough to lube the block, or just shortcuts, and leaves it dry. The rubbing block wears down to the point of just barely nudging the arm, but the dwell is so far off the car won't run.

Then there is the opposite problem, where someone over lubes the rubbing block, and it throws grease on the contact surfaces of the points, causing high resistance across the points. It's also important to lube the rubbing block on the correct side to prevent the lube from being thrown onto the points, depending upon which way the distributor rotates is dependent on which side you lube on the block. The correct side is the leading side so the lube is carried across the rubbing block as the cam carries it onto the wear surfaces.

In my many years of dealing with point ignition systems, condenser just don't go bad very often, maybe twice I've seen a bad condenser in 50 plus years of wrenching.

Just my , and observations over the years of dealing with breaker point ignition systems. Hopefully something here may help.

[george kujanski]

I'm with Bill Hanlon..... sounds like the tach is connected to the wrong coil terminal. The tach should connect to the same coil terminal as the distributor points wire. The tach connected to the wrong coil terminal will do funny things.

George

[John V.]

Bill, sorry about that. I wasn't sure if the "other" terminal is correctly called a negative terminal so I was calling it the "other" terminal to distinguish it from the positive terminal that the Ignition Switch wire is connected to.

The Tach is connected to the coil -, same terminal that the coil to distributor wire is connected to. I'm not sure what other wires are actually connected to the Tach at the Instrument Panel. According to the Shop Manual, to remove it, you remove the power lead and the lamps (there are 2 lamp holders). For '64, you had your choice of Tach or Clock in the same pod opening. Removal of the Clock has the same instruction, remove the power lead and the lamps, also 2 lamps used with the Clock, although the power feed for the Clock is a little different than for the Tach. IIRC, the I.P. grounds to a bracket on the brake pedal and the metal housing for the Clock or Tach grounds directly to the I.P. itself, no separate ground wire used.

Only the Pink/Black wire is connected to the coil +. The Pink/Black wire is connected to the Resistance wire from Ign 1 (On/Run position) and the wire from Ign 2 (Start position).

I don't have a dwell meter. I assume that is just to rule out dwell as the reason for the no start? Any reason to believe the wrong dwell setting could damage the Condenser?

I've been thinking about turning the engine with a breaker bar on the crank snout to get the points open just to see them open. I suppose I could check the gap when they open. When I was just learning about 50 years ago, I was taught to set dwell by ear after installing new points. But that requires the engine to be running.

The engine idled and ran nice until one day it didn't and then idled and ran nice again with the replacement Condenser with no changes to the point gap. Assuming the dwell hasn't changed but only the Condenser has failed again, I'll install the NOS Condenser before messing with the point gap.

Is there anything else that could affect the Condenser that I need to consider before throwing the new Condenser in?

[25stevem]

You do not need the condenser in there to see if the system will throw a spark.

Just hook up a timing light and see if it flashes when the engine cranks.

You can tape the trigger of the light closed and do this yourself even.

There are only a few things that will kill a condenser.
Age.

Over heated motor.

Too high a voltage .

It also would not hurt to check a few cylinders ( like two on each bank) for compression just to confirm that your timing chain has not jumped.

[John V.]

Brad, I was just talking to my neighbor, he owned a NAPA store since the late '70s until he retired a few years ago and he was saying the same thing. Bad condensers were very rare. But he also said they didn't sell many points/condensers since sometime in the '90s. Prior to then, they mostly sold Echlin parts until guys started to refuse to pay $8 when the cheap parts were $1.50. Eventually, he says guys just opted for the cheap Chinese made stuff but mostly, by that time nobody needed points anymore, everything was electronic. He said eventually Echlin stopped making the good stuff, couldn't compete.

I told him that you can google failed condensers today and the internet is full of stories. It is no longer rare. And given that there aren't very many who actually run points these days, the issue is downright common. Most guys give up and put in a Petronix or the like. Lots of guys that still run points carry spare condensers and are prepared to install them on the side of the road.

The cam was lightly lubed last time so I left it alone when I put the condenser in last year. I'll check it again this time but suspect it is okay. No grease seen on the contacts, they look clean.

My neighbor offered to watch the points while I crank it, maybe get that done tomorrow. That will be a big help. We will check for spark at the plug too while we're at it. I did post that I got the engine to cough a bit while cranking, I figured it had to be getting some spark for it to do that but with the 2nd set of eyes while cranking I'll be able to learn more.

George, I just saw your reply too. I think my last post clarified it but the Tach is connected to the coil -, same terminal that the coil to distributor is connected to.

I've read that Tachs can cause ignition issues but not sure they can cause the condenser to fail. Especially since the ignition is not running thru the Tach, the Tach is simply using the coil - terminal for a signal wire correct?