Warm engine misses

[Tom Bryant]

Man I know how you feel. I still work on these things at 68 and I feel it for a week.

Since you are using a remote starter just take out the number one spark plug. Hold your thumb on the spark plug hole and turn over the engine with your remote switch. When number one is coming up on the compression stroke air will blow your thumb off (the hole, not your hand). Stop cranking when you feel the pressure building and gently bump the starter until the balancer timing mark lines up with the 0 on the pointer. You are now at top dead center on number one. Now you can check the rotor orientation to the cap posts for number one. No need to mess with valve covers.

Tom

 

[Bo Dillingham]

To VetteHead Mikey and Tom Bryant,

Thank you both for your patience and advice.

Now, I did the "Remove spark plug #1" method to confirm TDC, and double checked with the timing mark the second time around to confirm that I had it right (Second time around I could blow air into the plug hole).

However, I do have the rotor aimed at the #1 plug (at TDC) and the #1 plug wire is in the distributor cap in the hole occupied by #7 in your photo (as in my set-up, that hole points to the #1 plug), but my distributor cap's service window is approximately where the number "1" digit is in your photo, and my vacuum unit is about where the number"8" is in your photo. (Please note that coincidently I had moved the coil to the spot where it is in your photo, instead of in front of the points service window where it used to reside).

Sadly, I do NOT see a ballast resistor. When I converted from PerTronix back to points and plugs, I had to make a "lead out wire" to go from the points to the coil, but I did not see a ballast resistor anywhere under the hood. Is that something that might be removed when PerTronix is installed? Or is it apt to be under the dashboard as opposed to the engine compartment (I have looked under the dash and saw nothing that looked like the ballast resistors that I have seen in internet tutorials).

Before I go to the trouble of rearranging all the distributor wires, I am going to get some long overdue work done in my business, and see if I hear back from any of you regarding the ballast, the plug wires, etc, etc. Also, if the plug wires were arranged as they are in your photo, would the rotor still point to the number one plug at TDC? (I'm not sure I understand about rotor position from your last post).

BoDill

 

[Vettehead Mikey]

To VetteHead Mikey and Tom Bryant,

Thank you both for your patience and advice.

Now, I did the "Remove spark plug #1" method to confirm TDC, and double checked with the timing mark the second time around to confirm that I had it right (Second time around I could blow air into the plug hole).

If #1 piston is at TDC and you can blow air into the plug hole, the piston is at the top of the exhaust stoke, not compression. Turn the crank another 360 degees.

 

[Bo Dillingham]

To VetteHead Mikey,

"Sorry if I confused you. The way that I wrote my post was intended to convey the idea that I checked for TDC by putting the crankshaft at Zero and trying to blow into the spark plug hole, and it was airtight. Then I RECHECKED by rotating the crankshaft 180 and blowing into the spark plug hole, which was easy. I assumed that the only time that I would not be able to blow air into the hole is during the compression stroke, and I picked TDC to try it out. At about 180 degrees away, I could blow a little air into the hole, so I assume that one of the valves must have been open at least a little bit.

Also, I have spent a little time (I can't do much as I have to get some business work done) looking at ballast resistors on the the Internet, and I definitely do NOT see one in my car. I read that the ballast resistor only comes into play after the engine starts, so I assume that it is not the problem (although I intend to replace the ballast before I drive the car anywhere; IF I ever get it started!!!!).

When I get some more time, I will try to check voltages as suggested before.

BoDill

 

[Vettehead Mikey]

T
Also, I have spent a little time (I can't do much as I have to get some business work done) looking at ballast resistors on the the Internet, and I definitely do NOT see one in my car. I read that the ballast resistor only comes into play after the engine starts, so I assume that it is not the problem (although I intend to replace the ballast before I drive the car anywhere; IF I ever get it started!!!!).

When I get some more time, I will try to check voltages as suggested before.

BoDill

It's very possible that someone removed the ballast resistor. Some models of Pertronix do not require them.

On your other question of 'where should the rotor point while at TDC on the compression stroke', the picture I linked to was how GM did it at the factory. The rotor in that case would point at the number 1 cap tower, and the spark plug lead would got to #1 plug.

The idea that the rotor MUST point to the number 1 cylinder confuses the subject. The rotor can point anywhere you like- as long as the wires are arranged accordingly.

 

[Bo Dillingham]

To VetteHead Mikey,

Again, thanks, and especially thanks for a quick reply. Without overstepping by bounds, I kind of assumed that the orientation of the rotor, etc. was not dependent on the #1 cylinder, although virtually every "Tune up" tutorial that I have ever seen for small block chevys assumes that. For that reason, I guess I migrated to that orientation. Also, my vette has a high-rise manifold, so the "Point service window" would be inaccessible in the orientation in the photo. With my distributor rotated about 75 degrees clockwise from the position in the photo, my number 1 plug wire is in the port where #7 wire is in the photo, and points directly at the #1 cylinder.

Again, at TDC, the rotor points to number 1.

ALSO, I just noticed an empty screw hole in the firewall next to the brake fluid reservoir, and I assume that is where the ballast went.

Again, thanks, and I have to go back to work (at 70 years old, I now work at home), but I still plan to try to check the voltages (probably tomorrow).

I REALLY REALLY appreciate your help and especially your patience. I'll let you know if I learn anything....

BoDill

 

[Bo Dillingham]

To VetteHead Mikey; Thank you for the compliment on that last post!

Now, I got out my antique volt meter and measured 12 volts at the coil positive with the key "On" and a little less than 12 at "Start". Not that you asked, but I got around 75 volts on the coil negative (if I did it right? and read it right?). I was considering putting the volt meter at the end of a spark plug wire and fooling with the start button to see if I got a reading, but decided against it until I checked with someone to see if that's a smart thing to do (and what voltage to expect). Is that possibly on your list of "Next suggestions"? If so, can you tell me what to expect?

Also, I went to the nearest auto-parts store (Autozone) with the idea of buying a Ballast Resistor, but they did not have one in stock. As a matter of fact, the young man showed me the selections available on his computer and I had a choice of a standard ballast resistor and a heavy duty ballast resister. I did not want to tell him to order one for me until I find out what a heavy duty ballast resistor is for (regarding a small block chevy).

So, I've got 12 volts at the positive, and I'll put in a ballast within the next few days; probably a standard ballast.

Any more ideas in the meantime?

By the way, and not that anyone has asked, but when I try the starter, I've got plenty of spin. I mean the engine makes a lively effort to start.

Thanks again,

BoDill

 

[Tom Bryant]

I don't think it makes much difference where you get your ballast resistor but it needs to be 1.8 ohms. Some places list replacement ones for our cars that aren't the right ohms.

Tom

 

[Vettehead Mikey]

Now, I got out my antique volt meter and measured 12 volts at the coil positive with the key "On" and a little less than 12 at "Start". Not that you asked, but I got around 75 volts on the coil negative (if I did it right? and read it right?). I was considering putting the volt meter at the end of a spark plug wire and fooling with the start button to see if I got a reading, but decided against it until I checked with someone to see if that's a smart thing to do (and what voltage to expect). Is that possibly on your list of "Next suggestions"? If so, can you tell me what to expect?

Getting 12 VDC with the key 'on' sort of confirms that there's no ballast resistor upstream of the coil but at least you're getting juice that far. Getting a little less during 'start' is to be expected, this coming from the starter load.

No idea why you saw 75 volts at the coil neg. terminal.

Putting a VOM on a spark plug wire will indicate and prove nothing. Try putting a spare plug instead.

Is the current from the coil negative interrupted when the points open?

Do you have a dwell meter to see if your points are anywhere close?

I swiped this diagram from the interwebs, it might help:

 

[Bo Dillingham]

To All;

This"ll make your day..........

A friend of mine "knew a guy who knew a guy" who "REALLY knows Corvettes", and put me in touch with him. He showed up this afternoon in a beat up old car, wearing rather well-worn clothes.
He had NO TOOLS other than a screwdriver with an indicator light built into it (you know the kind; with an alligator clip on a wire coming out of the handle). He simply smiled at me and said, "Don't worry, I'll have this running in a few minutes".

He checked a few things with screwdriver/trouble light, and then pulled the distributor cap and took out the BRAND NEW POINTS!!! He cleaned the points contact surfaces with a rag and some spit, and reinstalled them.

The Corvette FIRED RIGHT UP!!!

He smiled and said, "You did a good job with everything except cleaning the points. Back in your day (he saw all my tools and spare parts laying around, so I told him that I was an active gearhead about 30 years ago), when you bought distributor points, they were probably rather new equipment. Nowadays, points might sit on a shelf for years, and develop a sort of invisible film on the contacts. If you don't clean 'em real well, you wont get current through them. When I saw that you had voltage at the coil, but not at the spark plug, I figured that the glazed points were the problem."

After that, I felt bad because he gave up his afternoon and traveled to my garage to help me, plus he stuck around and helped me tune up the whole engine, etc. etc. When I asked him how much I owed him, he answered, "Ten bucks will by me breakfast", so I gave him $20.

I don't know what he's having for breakfast, but I'm having humble pie!!!!

I'm putting the ballast resistor in tomorrow after breakfast.

BoDill

 

[Mac]

Those kind of "diamond in the rough" guys are rare. I hope you grabbed his contact info in case you need him again?

Mac

 

[Bo Dillingham]

To All,

Sadly, I'm not out of trouble yet. This morning I installed a ballast resistor (since there was a splice in the wire that would connect to it, I assume that the former Ballast was removed from that spot when the PerTronix was installed) into what I firmly believe to be the previous connection spot. When started, the ballast smoked, and the engine would not stay running unless at 1500 RPM or more. Any less than 1500 and it would slow down and die (ironically the very problem that I had in the beginning of all this!)

I tried to go on-line to find out if the coil that I bought at Autozone (Part number C819) might have a built-in resistor, but could not find that information. (The man at Autozone couldn't find out either.)

While on-line, I saw a mention of an Ignition Control Module, but again couldn't confirm if my 65 should have one or not.

So, if you know whether or not a 65 should have an Ignition Control Module, let me know, and tell me where to look for it. Also, if you have any ideas as to why a brand new Ballast would smoke, I'd like to know that too!!!

The mechanic who helped me get started is on another job right now, but will call me when he is available. After the last few days, I would rather pay someone who is active right now in car repair rather spend any more time guessing at solutions myself.

I'll keep you posted.....

BoDill

 

[Vettehead Mikey]

It's normal for a ballast resistor to initially smoke, it's just a bit of oil burning off the resistance coil.

All coils have a resistance value on both the the primary and secondary circuits. In digging around, I can find no definite answer in the resistance of the new coil you bought. Is it marked on the package? I believe the stock coil was around 1.5 ohms.

The ballast resistor is around the same 1.5 ohms, going from memory.

No idea what ignition control module you've found. Doesn't apply to your car.

Your latest description of the engine not idling sounds more like carb leaking and flooding the engine, not ignition.

 

[Bo Dillingham]

To VetteHead Mikey and All,

First, Thank you for all your kind attention!!

Now, since I am waiting for my talented mechanic friend to call me, I have another problem that I was going to save for further discussion IF it didn't go away after the engine was running for a few days, but I might as well put it out here now. When we got the engine running yesterday, the timing mark seemed to wander a little. With the engine running, and the timing light aimed at the mark, the line on the harmonic balancer (I think that is the right word?) did not show up as being steady, but would appear to jump around at around plus or minus a few degrees with EACH flash of the strobe light (at various points between about 0 and 8 DBTDC).

"My mechanic", named "Matt" by the way, said at the time that it might be the timing chain, but we were tired and thought we would see what happens after the engine was running for few days. As long as you guys are watching this topic, I welcome any insights that you might offer. Since the engine was rebuilt not many miles ago, I would expect this "timing mark" problem to be more like a malfunction of cheap points, or a loose mounting of something, etc. etc. RATHER than the relatively new timing chain. Obviously, I have not solved some of the other problems yet, so maybe this will go away once the engine is running smoothly?

BoDill

 

[RestoCreations]

Unfortunately, I don't have time to read through the previous posts, but Im going to assume after 3 pages that most everything has been tried to resolve this issue. I've only had the same issue with one car before, a 64, and I literally tossed money at everything trying to fix it. I followed all advice on tuning the carb via Lars' instructions, had the original distributor and carb rebuilt, made custom spark plug wires, etc. and so on. Finally, i just replaced the points with the breakerless ignition kit and the problem was solved. NOTE: you must make sure to use an original style coil as per their instructions. I am now having a similar issue on another car with a 283, even though I had the distributor rebuilt and set up by a pro, and plan to install the same system. It's expensive, but worth the money. I have had several pertronix systems and distributors fail and will never use their products again!
Breakerless Ignition

 

[Bo Dillingham]

To All,

This being Wednesday night, and my business is "open to the public" Thurs, Fri, and Sat (I have a leather shop named "Old Man Leather"), so I won't get much chance to work on the Vette for a couple of days, but I have some questions (or you might call them "comments") in the meantime:

The following showed up tonight after "My mechanic", whom I will call by his name "Matt" from now on, came to my garage only to witness the Vette start right up and run smoothly, with the timing mark steadily on 4 DBTDC.

The car starts up well, and sitting in the garage it will rev until it scares me without a miss, but when I took it out on the road, it missed even at low speeds. It seems to idle just fine, even at street lights and stop signs, and is set at about 750 RPM. As soon as I get going, I get a slight miss. At a stop-light it smooths out again, and is smooth for a little while during initial acceleration, but starts missing shortly after getting going.

Another thing is that the timing is set at 4 DBTDC because it dies if we turn it higher. It seems to me that I used to set small block Chevies to at least 8 DBTDC in days gone by, but I don't trust my memory enough to argue with Matt.

Matt said that he thinks a carb rebuild is in order, and he has agreed to do it if I don't have the time, etc. I think I'll take him up on it, but I thought I'd mention this "missing" anyway to see if anyone has some ideas. The thing to remember is that the car DOESN'T miss when its standing still in the garage, or at a stop sign, only when it's rolling down the road!

It may be few days, but I'll continue to report.

BoDill

By the way, IF I was going to invest in another electronic ignition, I would want to solve all the running problems first the old fashioned way.

 

[RestoCreations]

I don't believe you have a carburetor problem, especially if your timing is bouncing around.

A few questions

1. Do you have a picture of your engine with the air cleaner off?

2.You say you have a high rise intake, which one? Is it dual plane or single plane?

3. What carburetor is installed?

4. Have you checked your distributor gear?


In the meantime, here are three articles I highly recommend.
How to properly install your distributor

http://www.corvette-restoration.com/resources/technical_papers/Distributor_Installation.pdf


How to set your timing for peak performance

http://www.corvette-restoration.com/resources/technical_papers/Engine_Timing.pdf

How to Tune a Holley
http://www.corvette-restoration.com/resources/technical_papers/Holley_Carb_Tuning.pdf

 

[Bo Dillingham]

To RestoCreations and all,

Since I am in the middle of a workday, I'll have to give short answers and get back to my business......

1. I do not have a photo, nor a cell phone, but I will try to get a picture over the weekend.

2. My highrise is a "Performer 2101", and I believe that is a single plane, but I'm not even sure of that.

3. Carburetor is a Holley 4165.

4. No, I have not checked the distributor gear. I have pulled the distributor and reinstalled it, but did not examine it closely, as I did not suspect it of being the problem. Again, this is something I could do over the weekend, though my guess is that I would have noticed a bad tooth, extreme wear, etc.

As far as the photo of the engine is concerned, my distributor would be about 30 Degrees clockwise from your photo, or the vacuum unit points more towards the #8 cylinder. I put it that way because the distributor "Service window" was completely inaccessible in the orientation in your photo due to the highrise manifold. My number 1 plug wire is in the hole marked #7 in your photo, as it points at the #1 cylinder in my car.

I may have mentioned this before, but I can rev the engine sitting in the garage with no missing, but out on the road, as soon as I get rolling I start getting this slight miss (it feels like I'm driving through a barrier every few yards or so; like a bump in the road but with no up-and-down motion).

As always, thanks for your time and attention, as I realize that this post has become rather lengthy, and frankly, this problem seems to baffle the few people I've talked to so far.

BoDill

 

[RestoCreations]

I don't think the problem is baffling. It's probably something quite simple that is being overlooked. Just because you replaced the pertronix with points, does not mean that the points are not now the problem.

Your intake is actually not a high rise. It's more or less a standard replacement. The good news is that it is a dual plane and not a single plane. Single plane intakes are not good for everyday driving.

When you have a chance, get the exact part number of the carburetor. If I were reasonably close, i would offer to come by, but since I am in central Alabama that is not an option.

 

[Bo Dillingham]

To RestoCreations and all,

Again, I'm working so this will be short...

I'll get the Carb P/N probably after work today, but I thought that I might mention that I replaced the PerTronix with a set of points that have the condenser built in. I have no idea if this could contribute to the problem, but I have NEVER used them before. I don't remember them being available when I was a "gearhead" back in the early 70's. If they were around then, I never used them.

Also, while at work, I glanced at the "TunedByLars" article on tuning a Holley. Tech Tip #4 mentions that the accelerator pump can cause, "hesitation, stumble, or backfire..." so I will likely read all the bulletins that you recommended tonight. This stuff starts flooding back after 40 years and open heart surgery!!! By the time this is over, I might actually remember some basic tune up skills!!!!

In addition, I looked up the intake manifold part number and found it to be a "Low Rise Dual Plane". My apologies for not knowing......

Again, thanks,

BoDill