[NeighborsComplaint]

Assuming your analyzer is working, your points have closed up. Dwell should be 30 degrees. Your points either vibrated loose or are burned and bridged momentarily, forming a pointed tip which results in a less than optimal point gap. Your spark intensity drops and you foul your plugs when this occurs.

Pick up a cheap ignition file at the auto parts store and run it between the points contacts to smooth them. Reinstall your rotor and cap and re-adjust your dwell. You can do it with the engine running or pull the coil high tension lead and have someone just crank the motor over while you adjust the dwell with an allen key inserted through the window on the distributor cap into the adjusting barrel on the points. That will get you running fine until you can buy a new set of points.

If you don't know how to do this with the dwell meter, then leave the cap off, bump the ignition until the rubbing block of the points is on a high point of the distributor cam. You can insert the rotor and rotate the distributor cam slightly by hand to a high point. Then adjust the point gap with the adjusting barrel screw until you have a 0.016" gap between the points contacts.

A bad, shorted-to-ground condensor will give a no spark, no-start condition or if failing, it will be reactive to heat and intermittently kill the motor. Following a cool-down the engine will fire again and run until it shorts again as it is heated up by the motor and current flow. It will fail in completely in short order after this starts.

Also not sure where your condensor is mounted, on the outside of the distributor housing maybe? They are typically affixed to the points breaker plate like this set. The canister coming off the back of the points is the condensor.

[racerboy]

Here are what the points look like. Should there be a hole through the fixed base or should that be solid?


Here you can see through the base to the paper towel



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[Joe's Garage]

You've found at least part of your problem.

And, yes, the hole is there on some manufacturer's points to ventilate them and keep the points cooler.

[Schurkey]

Originally Posted by racerboy

I set the Range Selector and Function Selector to ‘Points’.

Originally Posted by NeighborsComplaint

Assuming your analyzer is working, your points have closed up. Dwell should be 30 degrees. Your points either vibrated loose or are burned and bridged momentarily, forming a pointed tip which results in a less than optimal point gap. Your spark intensity drops and you foul your plugs when this occurs.

NO. His meter is not measuring dwell. The meter is measuring point conductivity, as shown on the "Points" scale farther "down".

He'd have to turn the selector knob to "Dwell" to measure dwell. (Which would be a good idea once it's reassembled, and after that, verify initial timing.)

Originally Posted by NeighborsComplaint

Pick up a cheap ignition file at the auto parts store and run it between the points contacts to smooth them.

For fook's sake, DO NOT file, sand, grind the contacts to make them pretty. They're Tungsten-plated for heat resistance, any abrasive will remove the Tungsten, AND "filing" points removes surface area of the contact. The contacts will degrade quickly after they've been "filed". These contacts are showing poor conductivity, perhaps they've been burned due to lack of proper ballast resistor, or a low-resistance coil. Maybe there's some other reason--lack of a good PCV system, worn distributor bushings, or excess blow-by could push oil vapor up the distributor shaft, the oil mist under the distributor cap could cause points burning. No matter what--those points need to be replaced (assuming the Craftsman Analyzer is accurate in showing the points have substandard conductivity.)

GM service procedure was to NOT remove the cone of metal transferred from one contact to the other. The point set was usable until the cone of transferred metal was taller/wider/bigger than the point gap--and then the point set should be replaced. The metal transfer is still contact area that shouldn't be removed.

Look, folks--I haven't held a set of points in my hand in thirty years. I use "Points" distributors as oil pump primers, after I yank them out of the engine and replace 'em with HEI. So my eyes are not calibrated to see problems with points--but--those points don't "look" bad to me. Maybe they are bad, maybe I'm senile, but I remember used points looking much worse than that. The only reason I question them is that crappy-looking point sets came out of cars with 12,000 miles sometimes more; and these came out after 250 miles.

Originally Posted by NeighborsComplaint

Also not sure where your condensor is mounted, on the outside of the distributor housing maybe? They are typically affixed to the points breaker plate like this set. The canister coming off the back of the points is the condensor.

GM called the point sets with integral condenser "Uni-Sets", if I'm remembering right. We hot-rodders dismissed them as "junk" probably due to the stiffness (or lack thereof) of the spring not permitting high-RPM use. They saved time when doing a "points and condenser" replacement on "ordinary" cars for Dad and Grandma.

HOWEVER, the previous system was to install the points, with the condenser mounted separately on the breaker plate--NOT on the "outside of the distributor housing", using a single screw and hold-down bracket. The condenser lead was tucked under the points spring just like the coil lead. Once somebody installed a "Uni-Set", the car got Uni-Sets from then onward, because the condenser hold-down bracket and the machine screw were long gone. The "mechanic" wasn't about to waste time removing the old condenser from the bracket, and then re-attaching the empty bracket to the breaker plate with the screw. All that went into the garbage can.

I'm reasonably sure the condenser of this distributor is behind the mainshaft, invisible in the photo--but he should check to be certain.

https://www.summitracing.com/parts/a...make/chevrolet

Originally Posted by racerboy

Here are what the points look like. Should there be a hole through the fixed base or should that be solid?

The hole in the stationary contact allows for cooling airflow. Totally normal.

[NeighborsComplaint]

From the latest pictures, the points are fine.

Filing excessive metal deposited between the points is a temporary measure when the gap is closed up to the point that plugs are fouling and the vehicle becomes undrivable. GM did not condone it in the long run but it will get one to and from the parts store to get a new set of points if excessive electrode transfer (cone) has occurred.

These cars are not driven like they were in the '60's so points don't fail from high mileage. There is usually a resistance issue that causes a failure or just faulty materials.

[racerboy]

Just as everyone said, the condenser was tucked away from view. All of the screws holding the points and condenser were tight and the condenser wire was also tight. There is no abrasion on any of the wires. A friend of mine gave me a new set of points, but if the ones I already have are still good, I’ll just put them back in for now.

I did get a new set of plugs (R45S) and set the gap to .035. I haven’t restarted it since I put the plugs in because I’m not sure that could be the root cause?

As I said in my original post, car was running fine and then I felt this little stumble and everything went downhill from there. I didn’t over-rev it or anything like that. I was just cruising at about 50 mph when it first stumbled.

I did have someone crank the car with the fuel going into a container and it seemed to fill that pretty quick, so I think the fuel pump is probably ok. I’d never done that before and the fuel came out in spurts as opposed to an even flow, but I’m assuming that’s by design of the eccentric.


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[Formulas]

I used to pull 400 grit paper through the points when they were closed 2 times each side got rid of high points from arc transfer

I would do this rather than a file to keep surfaces perpendicular

I usually did this just once in the points life then replaced them the next time I felt like they were long in the tooth usually early fall time I replaced them and early spring time dress them


But I just run HEI's. since about 1983 ish.

[Tom Vaught]

Originally Posted by racerboy

I did have someone crank the car with the fuel going into a container and it seemed to fill that pretty quick, so I think the fuel pump is probably ok. I’d never done that before and the fuel came out in spurts as opposed to an even flow, but I’m assuming that’s by design of the eccentric.

1) The fuel pump "Arm" is driven in a cyclic motion by the "Excentric" located
on the front of the camshaft.

2) As the "Excentric" rotates it compresses a spring in the fuel pump housing.

3) The spring is compressed with the "Excentric" is in one position and is at
installed height in the other position.

4) When the engine is cranking/running at idle speed, the there are "pulsations" in the supply to the carburetor.

So you are absolutely correct that that pulsing at low speeds is caused by the
"Excentric" operating at slow speeds and is apparent. THE "Excentric" IS ALWAYS PULSATING, THE TIME SPAN BETWEEN PULSES JUST SHORTER WITH INCREASED RPM.

Some applications have a small return to bleed off trapped air/pressure.
Mostly on A/C built vehicles.

Tom V.

[389]

Go on e-Bay and get a set of Accel 8104 32 ounce points. Get the 110128 points and condenser kit. Look for the vintage accel points that are from the seventies. There the best.

Those points you have are, well, just get the points I suggested. If you can't find them I have a set I can sell you..

Set the dwell to 30. Make sure you have the vacuum advance plugged and keep it plugged through the troubleshooting process..

If you have a return line from the pump to the tank the gas line will always be empty when removed.. If you don't have one I would get one. Just tee the line going to the carb and run a 1/4" line back to the tank and install a piece of 1/4" tubing next to the other connections in the access plate.. But it's not the issue your having.. The return line keeps the fuel cooler and mixed up, we especially need this with todays moisture attracting Ethanol.

I really think its the points..

Also when its idling, Check the voltage at the coil + positive. It should be around 9-10 volts. When started it should jump up a volt or two then settle back down under 10...

What ever you do keep the distributor you have, its a very good unit. Frankly, you all ready have one of the best ignitions going.. If you want a more powerful ignition connect a Vertex Z-6 CD box to it.. But for now, I would put the NOS Accel 32 ounce points and condenser in and keep on trying..

Don't start throwing money at it. no matter how tempting, take your time with it and enjoy the detictive work.. It's not like you need the car to go to work or anything..

[racerboy]

So I tried putting in the new points. That didn’t work. I followed instructions to set the gap at .019 when the rubbing block was on the peak of the cam. Engine wouldn’t start. Figuring I didn’t set the gap right, I put the old points back in. Still no start.


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[Schurkey]

Originally Posted by racerboy

So I tried putting in the new points. That didn’t work. I followed instructions to set the gap at .019 when the rubbing block was on the peak of the cam. Engine wouldn’t start.

GAP is CRAP. Set points by DWELL, always. And you have a dwell meter; although there's no guarantee that it's accurate.

"New" GM-style external-adjustment point sets are nearly always close to perfectly pre-set right out of the box. Don't dick with 'em until after the engine is running.

Originally Posted by racerboy

Figuring I didn’t set the gap right, I put the old points back in. Still no start.

Do you have spark at the coil wire?

Is the coil + powered with the key turned to "Run"? You'll have battery voltage, or you'll have ~6--8 volts, depending on whether the points are open or closed.

Did you put the rotor back on?

[racerboy]

Originally Posted by Schurkey

GAP is CRAP. Set points by DWELL, always. And you have a dwell meter; although there's no guarantee that it's accurate.

"New" GM-style external-adjustment point sets are nearly always close to perfectly pre-set right out of the box. Don't dick with 'em until after the engine is running.


Do you have spark at the coil wire?

Is the coil + powered with the key turned to "Run"? You'll have battery voltage, or you'll have ~6--8 volts, depending on whether the points are open or closed.

Did you put the rotor back on?

I have 6v at coil with key on.

I am such an idiot because I forgot the rotor. I put it on with the new points and went to start the car and lost my hearing. Huge backfire through the carb. But then it still wouldn’t start, but it was trying. I put the old points in and tried again. Another loud backfire and then the battery lost its oomph. Now I have it on a charger.

I probably did some damage to the carb with those backfires, didn’t I? I should have just let it sit so that fuel charge could dissipate.


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[steve25]

There’s nothing in a Q jet carb to be harmed by a back fire.

You must have got the firing order wrong for back fires to now happen!

[racerboy]

Hi Steve. I checked the firing order and it looks correct. I’m calling it quits for the night.


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[mgarblik]

Not to insult in any way, but some of the rotors are made so poorly, it's possible to screw on the rotor with the square and round locators on the underside reversed. That would put the rotor out of phase 180 degrees, cause a loud backfire and not let the car run. Check that to be sure.

[racerboy]

Originally Posted by mgarblik

Not to insult in any way, but some of the rotors are made so poorly, it's possible to screw on the rotor with the square and round locators on the underside reversed. That would put the rotor out of phase 180 degrees, cause a loud backfire and not let the car run. Check that to be sure.

Thanks mgarblik. I actually learned this very thing this morning. I did have the rotor mounted with the 'square peg in a round hole'. Doh. Now my battery is too weak to turn the engine, and the Associated battery charger I bought in June isn't working. This is not my week for anything electrical-related. lol

I am going to pull the battery out of my Trans Am to see if I can get the GTO running again.

[rockdoc]

Originally Posted by steve25

I bet that in your distributor the wire that runs under the breaker plate has totally dry rotted insulation with a lot of it missing off the wire, and when the plate move as you give the motor throttle the power to the points gets shorted out!

I know you've had dozens of suggestions, but I agree with Steve. I had a problem exactly like yours and eventually discovered that the wire to the coil from the distributor was barely connected and frayed at the connector. It is difficult to see the wire in the distributor, but you can see it. Turns out I caused the problems when I replaced the points and condenser. I replaced the wire and all of my problems went away (well, not ALL, but with the car).

Dave

[Rhagolin]

Originally Posted by racerboy

Here are what the points look like. Should there be a hole through the fixed base or should that be solid?


Here you can see through the base to the paper towel



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Did you check dwell when it was running? And you are correct some fuel should have come out when pulling the filter......

[tekuhn]

Dang, I'm getting dizzy just reading this thread. People keep throwing new things out to check when the previous suggestion was never followed-up on. I suggest eliminating possible problems one at a time.

The initial observation was no fuel ran out when the line was disconnected from the carb, and a fuel pump volume test was suggested. Did that happen? I don't find the results of that posted. Remember that a fuel pump might still be bad if it can't maintain the flow rate under pressure. The carb itself has been ruled out by swapping another in with the same results. A very lean condition would certainly cause the poor running symptoms being described and could be caused by a fuel starved carb or a large vacuum leak. Look for stuck PCV and power brake booster leaks. If the RPM is erratic, the timing could definitely be jumping all over the place due to both vacuum changes and mechanical advance input. If the debris that was found in the carb filter passed through the fuel pump it could definitely have damaged or clogged it (or even have come from it). There was a suggestion to fill the carb bowl through the vent tube and see if the engine runs well briefly until the level drops. Good suggestion. Is the accelerator pump stream strong and constant as the throttle is opened? Rule out lean fuel issues before moving to the ignition.

I'm not sure it's safe to criticize the spark plug condition without knowing anything about the camshaft. I've had engines that turned new plugs that black very quickly due to a large duration and overlap profile. If it lopes, it's fouling the plugs - pretty sure that's part of the price to pay for the awesomeness of a great idle . The factory points ignition is perfectly reliable, but will require periodic maintenance. As suggested, the condenser needs to be in spec for long points life. It's job is both in reducing arcing as the points break, but it also increases the strength and duration of the voltage generated by the coil. The red wire in your photo is clearly from the condenser. They are both cheap, so buy a good quality pair if you're not sure if yours are bad. If the restoration was done correctly, the factory resistance wire was retained in the wiring harness. As designed, full 12V is applied to the coil primary + during cranking, but in the run position, the voltage is dropped through the resistance wire to limit the current to extend point life. With the engine running, you should measure somewhere in the neighborhood of 7-8V. If you have 12V running, the points will not live. You can install an external ballast resistor to restore this function, but it needs to be wired so that full voltage can bypass it during cranking. Make sure the coil bracket is tight to both the coil and engine. The coil secondary return ground is through it.

Keep us posted.

[racerboy]

OK, we are back to square one. I got the car running again with the original points. It does have a working q-jet on it.
1. I did check the fuel volume. Had someone crank the car and pumped the gas into a container. It seemed to fill that container quickly. It did come out in spurts, not a steady stream, but I figured this was by design.
2. Checked the brake booster hose, the PCV valve and all other vacuum lines.
3. The black wire that goes from the coil to the points is not worn, but it does feel a little brittle. It also has a little metal clip on it (see photo). Not sure what that clip is for, but just thought I'd bring it up.