Technical My Engine is Cursed.....I need to consult a Wizard.

Lately, I've been attempting to start my Pontiac, to no avail. At first, I thought it was a coil problem. There was power going to the coil (from both from the starter and the ballast resistor) but my testing light didn't show any power coming from the big plug on the coil leading to the distributor. I had a brand-new coil, but I was sure that this was the problem with the car, so I tried 3 different coils and had the same results every time. I then read on the internet that the big wire on the coil is just "a path to ground" and shouldn't have power.......is this right?

I then checked the #1 sparkplug for power while cranking the engine...nothing. Is this a distributor issue? I should mention that I did some work on the distributor (points (.020 gap) condenser, and rotor), but I have checked it and I'm pretty sure I have it right (it seems simple enough).


I'm really stumped here, so I really appreciate the help!

 

Gap may be a tad wide. This link shows the tune up specs for a 55 and says 16 thousandths on the points. http://www.secondchancegarage.com/c...cs/1956-pontiac-316-205hp-v8-engine-specs.cfm
You are setting the points with the rubbing block on the Tip of one of the lobes of the distributor?
This is obviously not a Pontiac v8 distributor but it will serve to show that you need the rubbing block on the points on the tip of one of the lobes of the distributor cam to set the points right. You can see the lobes and where the rubbing block or what's left of it is against the tip of one an that the points are open. If you set the points at any other place they won't close when the distributor turns and if you set them too wide they won't close.

I used to live in McGregor and worked in Waco in the 70's and still have some friends around there.

 

Side note, you won't get any voltage that will turn on a test light out of the secondary tower of the coil. You can test a coil with an ohm meter reasonably accurately though.

 

Hmmmmm......I have been setting the points on the tip of the lobes. I just tried a .016 gap and the plug wire didn't set off my test light. Here's a picture of what my distributor looks like inside:

 

That isn't one of those drug store condensers is it? Try the old one if necessary.

 

You will not have voltage if the points are closed. Remove the wire to the distributor and check for voltage if you have voltage to the battery side and none to the distributor side bad coil if you have voltage there is a short in the distributor

 

Here's a good introduction to the workings of conventional points-type ignition systems. If the car is negative ground system, do you have the negative coil terminal wired to the points and the positive terminal wired to the ignition source?

http://www.jalopyjournal.com/forum/threads/hot-rod-technical-library-basic-ignition-systems.983424/

 

Current to/though the coil is as follows.....current from ignition switch via stater solenoid and/or ballast resistor into + terminal of coil......through the primary winding in the coil and out of the coil - terminal. From there to the distributor housing terminal (the terminal with the blue crimp connector in your photo) to the points terminal. When the points close, the circuit is completed to ground and resulting current flow in the coil primary winding creates a magnetic field in the coil. The points open as the distributor rotates, the coil primary current flow is interrupted, the magnetic field collapses across the secondary winding in the coil, creating and induced voltage spike in the secondary winding that seeks ground through the large coil wire...to the distributor cap coil terminal, through the rotor and out the cap by the spark plug wire attached to one of the spark plugs....jumps the plug gap to ground, creating the spark that fires the fuel/air in that cylinder.....engine runs if all else is correct.

Common obstacles to this path can be the condenser and the wiring in the distributor from the terminal coming from the coil to the points terminal. If that wire is touching ground before the points contacts, the coil will have uninterrupted current flow on the primary winding and the coil will not 'fire' when the points open.

Your problem is likely something very simple....something that looks right at a glance, but is not, in fact.
Another common problem with points is dirt or oil on the contacts themselves. Not necessarily visible to the naked eye, but there nonetheless and prevents current flow. With the points in the closed position, insert a clean business card or similar (3 x 5 card) material between the closed points and withdraw the card stock. you may very well see a smudge of 'something' on the card stock. If so, repeat another time or two, and electrical continuity of the points will have been restored.

Ray

 

Thank you for the link! The my car is negative ground, and the negative on the coil is wired to the points. I am starting to suspect the distributor cap. It looked really new, so I didn't replace it, but I probably should have as a precaution...it is a bit loose.
Engines make me feel like this :

Thanks!

 

the point gap is measured between the contact points, not at the lobes! When you turn the distributor, you should see the points opening and closing.



(if you already know this...sorry...but I get the feeling you might not? since you also don't seem to understand that a coil puts out 10,000 volts or more out the big terminal, and test lights measure 12 volts)

 

Did this start after you installed the new points and condenser? If so, try the old condenser


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What Jim posted in post 10 is what I tried to say in post 2. I guess I had ***umed a bit much as far as your knowledge on setting points. You put the feeler gauge between the contacts on the points and not between the rubbing block and the cam. When the distributor shaft rotates you should see the points open and close. That goes back to Hnstray's post in post 8 that gives an excellent explanation of how the ignition works an is right on with what I taught in auto mechanics cl***es.
I'm saving Jim's diagram for my library as that is a simple explanation.

 

Thank you, Mr48chev. My post was worded badly; I had meant that the rubbing block was on the tip of the lobe and I had been inserting the feeler gauge between the points, like squirrel's graphic. When I get the chance, I'll test the plug wires the right way with a grounded screwdriver.

Thank you, everyone for all of the help!

 

First thing is to get spark to the distributor cap,forget testing the wires till then. Pull the coil to dist wire out of the dist. and fix it so it's just 1/4 " away from a good ground and either crank the engine over or open and close the points manually, you should get a blue spark and a snap noise if points.condenser and the coil are good. Don't forget to turn the key on...

 

And don't forget to turn the key off as that can burn up the coil.


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well..........I have good news and bad news . The good news is that I seem to have ignition now! After I changed the distributor cap, I shoved a screwdriver in a spark plug and cranked the engine. With the key in one hand and the screwdriver in the other, I moved the screwdriver towards a good ground and heard a couple satisfying snaps! The bad news is that the engine still doesn't start. I have a line running from the fuel pump to a gas tank (and the fuel pump seems to be working) I've also been pouring gasoline into the carburetor (I tried to fill the float bowls too, but I don't have a giant syringe) AND using 3 second squirts of starting fluid, but the engine never fires. Even if my carburetor rebuild was messed up, I would expect that much fuel to make some noise? On a brighter note, I did notice that the engine cranks faster when it has starting fluid. I've seen this happen in video's of people starting cars that have been sitting. One of them explained as the engine firing, but very weakly. I seems like this might be happening here?


On a side note I found this thing:
A little bit of smoke comes out when I crank the engine. do you think it's a problem?

 

Buy a bottle of some kind of Lucas product that will help you with one of your vehicles and empty it.
Save the bottle and top so it can be used as a temporary fuel container. You can put a little bit of fuel into the carb bowl vent with this simple tool.
The smoke you speak of and the part appears to be some kind of crankcase vent. I'm picturing where a draft tube may have been used, pre PCV. A person might even be able to adapt a PCV valve into this, if that is what it is.
Have you performed a compression check on this engine yet? This may explain a lot more problems, and some you may not want to know.

 

If it's like many old Pontiacs. It probably jumped time from a bad timing chain. They usually do when you are cranking it. Put the engine up on #1 and see where the rotor is pointing. Turn the motor back and forth with a socket and breaker bar to see how much slack is in the chain. I have moved the plugs wires around to get one running enough to get me home , but it jumped again as soon as I tried to crank it after I got home. The plastic cam gear is usually the culprit.
Former Pontiac dealership mechanic ,but what do I know? Just a suggestion of where I would start looking.

 

Thanks, Southcross. Always check the chain first when your V8 Pontiac quits.

 

Thank You!!!! I just tested it and the timing is trashed.

 

Your welcome. Too many timing sets changed in my career to not check it first. Saves buying parts you don't need .

 

I agree with southcross.I have a couple Pontiacs run fine then shut them off and come back and they wont start.It was a jumped timing chain.Darn plastic gears.Check it as he said. P.S. I just read you last post. I am glad you found the problem. Bruce.

 

^Since my last post I've installed a new timing chain, have steal gears, and had the starter rebuilt. I also did a compression test (the motor manual lists compression at cranking speed, so I decided to try it) and I got a result of 0 PSI. I'm not sure I believe that, so I'm going to blame a broken gauge. When I unbolted the valve covers, I found the rockers almost unbolted, so I tightened them until the pushrods just started to feel firm, plus half a turn. Once I did this the engine developed a slight tick during cranking....I'm going to blame lifter problems for the noise.

I have checked the timing, rotor, firing order and carb adjustments carefully someone else has looked them over also, so I am reasonably sure that those aren't issues anymore. I have read that low compression engines tend to backfire (and this garbage definitely backfires).....

do you guys think this is a valve problem, or a compression problem?

I have a sinking feeling that a rebuild is in my future.............

Thank you, all for the help and advice.

 

Describe how you adjusted the valves, what order etc.


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It's not cursed or haunted....just outta time. It's actually showing signs of life! If it was mine I'd first:
Back off the valve setting that 1/2 turn extra you gave it after the push rods got snug...you may have them too tight.
It sounds like it's 180 out of time to me..something I'm very familiar with on old Pontiac engines..
I'd pull the distributor, marking the direction the rotor is pointing first. Turn the distributor shaft and rotor 180 degrees [1/2 turn] and drop the distributor back in. You may still need to turn the distributor forward and back to get it close enough to start. Don't give up on it. You're almost there!
After it starts you can then tighten up the valve adjustments as needed. 55 is the only year Pontiac that you can actually adjust the valves..you're lucky!
By the way.......Pontiac distributors turn counter clockwise. #1, then #8 [clockwise] then #4 etc etc...some guys get confused and wire them the opposite direction like a chevy V/8. You'll get it!

 

You didn't just tighten them all down as you found them when you pulled the valve covers, did you?

There is a specific sequence to follow, beginning with #1 at TDC, I don't know the Pontiac sequence, but a shop manual would sure help you out.

 

I made sure that each valve was closed when I tightened it. I'll do them properly with a torque wrench later.

 

Sounds like you're getting close. Valve problem and compression problem can be one and the same. Hopefully the timing chain set solved the ignition problem.