'62 Chevy II tune up gone wrong


#1

Hi,
Here’s my tune up journey: I changed the oil and filter. The filter was a bear to get off. After using all other methods, it ended with using a very large crowbar and a hammer to drive it off. I changed the radiator fluid. I also changed the spark plugs one at a time. I set the gap to .035 like my manual said.
After doing so, I drove the car and it bogged out in first and second. It would make an air spitting sound (like from an air hose) and then go. The power seemed to hardly be there at all. The car was also leaking oil. Despite this car’s age, it has never leaked a spot of oil until now. Super annoyed, among other things, I took it to a mechanic who has his own classics. (Mine is just an old beater.) I wanted to get an overview of what all needed to be done after the tune up.
He re packed the left wheel bearings , replaced the driver side wheel bearings, and said the oil was leaking from the head gasket and replaced that too. I picked it up and it bogged a little but not much. I got it home and the car was still leaking oil. It was on my paperwork that I mentioned those concerns but I wasn’t billed for servicing those concerns.
I drove the car about 6 miles to see how it drove and there were bogging problems the whole time. When I was leaving the store, it didn’t want to crank. It kept bogging out. I had to floor it just to go a little faster the whole way home. I cleaned the plugs one at a time, concerned that I may have gotten plug lubricant in the gap. I also loosened the distributor cap to turn it a little to listen if the car would run better. (Under the advice of my dad. I clearly have no clue about this stuff. This is my learning car). I also adjusted the carb. It was 7 in the rich and the book specified 1 in the lean. After doing this it sounded and rode a lot better. I drove it a few miles at 50 and then stopped to make a u-turn and go home. The car shut off and wouldn’t start. I sat there for probably 5 minutes and it finally started and I was able to get it home.
Fast forward a few weeks to today, started the car with the help of some starter fluid. It was idling high so I adjusted it 1/4 to the left. It sounded much better. My husband drove it the same course as I had the last time and a little farther. He said it was fine and didn’t shut off. I decided to change the fuel filter, which I had yet to do. It was a clear universal one. After I changed it and cranked it, it sounded horrible. Back to adjusting dist cap, carb and idle, trying to find the best sound and feel. I think I see a timing light purchase in my future. (The Dad said I didn’t need because I should be able to hear it.)
The concern I have now is that even after starting the car and giving it gas, the oil light dims and stays on bright (the oil is full) as if it doesn’t want to stay cranked. I don’t know what I did wrong in the initial work to cause all this. Any ideas?
Thanks :slight_smile:


#2

Forgot to mention this is the straight 6, tot


#3

maybe the engine has sludge and needs to be cleaned? also sounds like you may have a carb problem. You may need to rebuild carb.


#4

How old are the spark plug wires?

The act of removing old spark plug wires from the spark plugs to replace the spark plugs can damage the old spark plug wires.

Think about it. The last thing that was disturbed before the engine started running like crap was the spark plug wires.

I’d do a complete tune-up. Cap, rotor, points, and wires, along with the plugs.

Tester


#5

You need to find out all the tune up specifications for your car and get instructions on how to

  1. install and adjust the points (either a feeler gauge or a dwell meter)
  2. adjust the timing with a timing light
  3. adjust the carb mixture and idle speed with a tach

A newcomer has no ability to adjust any of this ‘by ear’. I wouldn’t, even with lots of experience.


#6

First, the plugs should probably be gapped at .032, not .035. You should also replace the points and the condenser at the same time. Gap the points as recommended in your manual. You’ll almost certainly need a dwell meter for that. Replace the plug wires unless they’re already new.

Get that timing light, and use it. It’s a pretty safe bet that you’ve retarded the timing so much that the engine is running so slowly that it’s not generating enough oil pressure to turn the oil pressure light off. It should be idling at about 650 to 700 RPM in Drive. You can check that with your new tachometer, the one that is part of your dwell meter.

Only after you get all this other stuff sorted out should you be fooling with carburetor adjustments.


#7

If the carburetor is flooding periodically all the adjustments and tune-up in the world are not going to help even a little. One of the reasons we don’t have carburetors anymore is that their performance is inconsistent.

Certainly finish the tune up as suggested, that’s good advice. But when it comes to the carburetor, you need to find an old-timer mechanic (no less than 50 years old) to inspect, adjust and overhaul as needed.

Replace oil pressure switch and retest. If the oil is loaded with gas, change the oil and use 10W40.


#8

Your car was designed long before any thought of ethanol being in the gas. Ethanol will really screw up an old carb. Messing with the ignition timing and all the other things you are doing is just getting you further off course. Your car likely has points and you didn’t mention doing anything about the points in your “tune up”. Start with a new set of points. It is best to set them with a dwell meter, but you can use a feeler gauge it that’s all you have. Then a new distributor cap, rotor, and condenser. Next is setting the timing with a timing light. Next is new plugs, but you’ve done that.

Once you have new ignition parts and they are set properly, if the car is running poorly still it is the carb you go to next. If the jets and seals in the carb are bad you can screw all the adjustments you want, but not get anywhere because the inside of the carb is messed up. The ethanol can actually cause the metal to corrode and flake off inside the carb. This causes the same symptoms as dirt in the carb. Bogging down could mean the accelerator pump isn’t working. This is a little pump that squirts a bit of gas when you press down on the accelerator. You check it for function by looking down the throat of the carb and push hard on the accelerator, you should see the squirt of gas clearly. No skirt, no function, and that will cause the bog down symptom. But, that’s the easy fix, likely your whole carb is a mess and the best option is to pull if off the motor, take it apart, clean it, and reassemble with new “rebuilding” carb kit pieces. This really isn’t easy, and most carbs should be rebuilt by a knowledgeable mechanic, and modern mechanics just don’t work on carbs anymore. A small motor shop is more likely to have a carb guy working there now.

If the carb is fine and still you have problems, then you go to the distributor. There is a vacuum advance and a mechanical advance on that distributor. The vacuum advance is to rapidly kick up the spark advance upon quick acceleration. You test it with a strong timing light. At an idle you watch the timing mark as illuminated by the light. When you give the accelerator a quick push the timing mark should literally jump very fast about 10 to 20 degrees to the advance side. If it doesn’t jump then that will cause the bog down feeling. If the spark advances slowly the mechanical advance is working, but you need the vacuum advance to work. The fix could be replacing the distributor, but first you check for vacuum pressure and the vacuum diaphram that is mounted on the distributor. The diaphram is right where the rubber vacuum hose attaches to the distributor.


#9

@Uncle Turbo’s advice sounds good but I believe you face a steep learning curve, @stenotab. And although I am often successful in reading between the lines here and in your case feel sure that the oil leak was at the valve cover and not the head gasket, it can be a hit and miss situation to decipher the problems when we aren’t working from the same program.

However, it is common to find the spark advance on the distributor mistakenly attached to manifold vacuum which causes severe hesitation. An experienced old school mechanic should recognize and correct that problem within a minute of opening the hood. Of course, if the vacuum advance diaphragm is leaking it won’t function and again that old school mechanic should catch that within seconds. And, the ethanol will cause some problems if it hasn’t already and you might expect that the carburetor, fuel pump and all rubber fuel lines would need replacing.

So, please continue on if you have the patience and persistence. There is a light at the end of the tunnel for those willing to walk the extra miles.


#10

I learned to work on engines with this very engine type. The 1 barrel carburetor is based on a 1932 design with few updates. With the ethanol in the fuel, you are likely shedding crud into the carburetor. The lean fuel condition caused by ethanol means that hesitation you feel might be a lean air/fuel condition. If the car is lean enough to backfire through the carb, you will likely need to rebuild it. Kits used to be cheap and the carb is very simple. Usually its is just a bit of carbon in the air slots below the throttle plate in addition to the ethanol crud. If you don’t know what I’m talking about, get a manual for this engine and read up. With ethanol in the fuel, the car is likely running lean. It wasn’t designed for this. You can drill out the jets slightly to help this but fix all the other stuff the posters mentioned FIRST.

I agree with others here that you NEED a dwell meter and a timing light. Get a vacuum gauge, too. All will be needed to keep this thing running. Welcome to vintage cars, they need constant service!


#11

Thank you all for your advice and tips. This is a huge help.


#12

Most of the points have been covered already but I saw one thing worth pointing out-

I cleaned the plugs one at a time, concerned that I may have gotten plug lubricant in the gap.

Well, actually two things. How did you clean the plugs? If it was by using a wire brush, don’t do that anymore. This used to be a more common issue when people regularly pulled and cleaned plugs but with the new plugs and cleaner running engines it has gone away. The steel wires in the brush are softer than the ceramic of the plug insulator and will pollute the insulator. Cleaning is best done using a sand blasting apparatus or just replace them, they are cheap enough.

You shouldn’t need lubricant at all, especially for an iron head. It’s even more concerning if you’re thinking you used so much it may have inadvertantly polluted the electrodes.


#13

@TwinTurbo‌ I didn’t use a whole lot of lubricant but also wasn’t careful about not getting it in the gap. The guy at the parts store just said to put it all around, my mistake about the gap. I cleaned it with brake cleaner with the straw, and also used a very soft toothbrush.

@JayWB‌ the manual I have is a Chilton and lists .035 for the gap. I will try .032 and see how that goes.

@UncleTurbo‌ @Mustangman‌ We have one station that sells ethenol free, but it’s a pretty far drive. I have used Gunk lead substitute in the past and got out of the habit. What is your opinion on this stuff? Does it help?


#14

Lead substitute might help keep the valves lubricated (one of the reasons lead was in the gas in the 1st place) but your issue isn’t related to valves or octane rating. What you should use regularly is a fuel stabilizer meant for marine use. These stabilizers are supposed to fight the effects of ethanol directly. So many marine motors are older than car motors that is why they need the “marine” stabilizer. With the age of your car, it needs it too. However, using a marine stabilizer will not undo the damage that may already have occurred. It won’t cure the current problem(s), but will help avoid some future problems.


#15

And after you get it tuned up and running right, repeat the points, condenser,and spark plugs every 10,000 miles. We also used to clean and re-gap the plugs in between at 5000 miles.


#16

You can get a timing light on ebay. Since they are pretty much obsolete except for situations like yours, they are inexpensive. They can be divided into 2 types: The adjustable kind that allow you to measure a large amount of advance (if say, the timing is so far off that it’s literally “off the scale”–the little stamped metal scale at the crank pulley/ harmonic balancer). The other type is the non adjustable type which only allow you to determine timing if the timing is within the scale’s range. It’s not hard, though, to bring the timing within the scale’s range by turning the distributor base one direction or the othr. One advantage of a used non adjustable timing light is that as long as the timing light’s strobe is flashing the timing light is accurate. It’s either on or off so it can’t be out of adjustment as long as the strobe is flashing.

Good luck & post back!


#17

Make sure you didn’t get a plug wire crossed. Did you change them one at a time or all 6 at once. Like someone mentioned before, make sure the vacuum advance on the distributor is working.


#18

karl

You’re making me feel old!

I still use my timing light from time to time. There were still plenty of cars with distributors in the 90s, and some of them were adjustable

As a matter of fact, I used it just last weekend


#19

I think it is great you are doing your own car repair. A 1962 is a good one to start with, the diagnosis & repairs are a little more straightforward. Parts availability might be a problem at some point, but sounds like you are doing ok. Good for you.

About tools. Not having the basic tools makes DIY car repairs a super-frustrating experience. A lot of potential DIY’er give up at that point. You have two strikes a’gin you. No prior experience, and incorrect tools. So be on the lookout for some basic tools. You definitely need a way to measure the rpm and a timing light if you want to do tune-ups. Be on the look-out for tools at bargain prices at flea markets etc. And if you need to, just go buy what you need at the time. Last weekend for example I was replacing he clutch master cylinder in my Corolla, and it is in probably the most inaccessible place possible. Sort of at the bottom of a well, to make matters worse, butted up a’gin the brake booster. I struggled for 10 or 15 minutes to remove the hydraulic line, then gave up and went to the tool store to by the proper tool. With that tool in hand, I had the hydraulic line loosened with no problem. It took like 20 seconds.

I’ll make one comment about your specific problem. It is very difficult sometimes to replace the fuel filter without introducing dirt particles into the fuel line, which will promptly clog up the tiny passages in the carb. Next time you do any fuel system work, you could try what I do, before removing anything, clean all the areas I’ll be working, especially the fittings, with a clean rag and some warm soap and water.

Stick with it, yield to common sense when need be, but never give up, and best of luck to you.


#20

@stenotab, I got rid of my leaded gas cars long ago so I can’t comment on Gunk. Ethanol free gas would be the best stuff to use but impractical. Maybe changing all the rubber fuel lines to modern EPDM would allow you to run regular gas with the marine fuel additive. You still might have to richen up the mixture (drill out the main jet), though.