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Decided to do complete tune up to my 71 s b. Changed usual wires,plugs rotar,cap, points. One problem. Vette won't start now. I've been over the wire placement to distributor, starting with #8 on distributor clockwise around cap. Set points to .016 open on the high cam spot in rotar shaft. Coil has spark and car getting fuel in carb. What am I missing here. Car pops when start is attempted. I'm thinking wires are crossed some how. Any suggestions would be welcomed. Vette has mild cam. Not sure what type. Would that matter? Thanks.
I suggest you find TDC, see where the rotor points, and make that 1, then go 18436572 clockwise.
Check your work on the points/condenser wiring. Maybe turn on the key, open the closed points with a screwdriver, and see if you get spark at the coil wire.
Normally, the points are set to at least get the car running right out of the box. Sometimes, they are not. Open the the points a little and it might be the problem. Get it running, then set your dwell. Even if you have a wire out of order, it would probably start. I'm betting on the points. You could even put the old set of points back in to see if it starts.
I bet your wires are crossed if it was running before. Here is a video for finding TDC. Big2Bird gave you the firing order here is a pic to help as well
Assuming you did not pull the distributor, at that position the rotor should point to 1 on the distributor cap. follow the diagram and make sure the wires are connected from the number on the DC to the correct plug.
If you pulled the Dist and it is not pointing at 1, pull the Dist and reinstall it with the rotor pointing at one when fully seated. if it is off once seated pull it and move one tooth until it is correct. when set correctly the dist will be near the middle of its timing adjustment with the rotor pointing to 1 on the DC. This leaves room for adjusting the timing.
Normally, the points are set to at least get the car running right out of the box. Sometimes, they are not.
I had a new set of points once that would not start the car. Very annoying! I ended up using a different new set.
One other time I couldn't start the car after my DIY tune-up. After much frustration I started to un-do what I had just done and noticed..... that I forgot to install the rotor!!
Assuming you did not pull the distributor, at that position the rotor should point to 1 on the distributor cap. follow the diagram and make sure the wires are connected from the number on the DC to the correct plug.
If you pulled the Dist and it is not pointing at 1, pull the Dist and reinstall it with the rotor pointing at one when fully seated. if it is off once seated pull it and move one tooth until it is correct. when set correctly the dist will be near the middle of its timing adjustment with the rotor pointing to 1 on the DC. This leaves room for adjusting the timing.
Ok. I've found TDC. However rotor points to # 7 on the distributor. I did not install distributor this way. Prior owner or whoever did that. Reset new wires accordingly 18436572 stating at 7, Dwelled new points and it really runs nice now. Will it affect performance if I leave it the way it is set up? As stated car has a mild cam.
It shouldn't affect performance, but you'll have to refer back to this thread every time you work on your ignition system in the future to remember how you set it up. It's best to get it set up the way everyone expects it to make future diagnosis and work easier on you. It's not hard at all to pull and reset the distributor. There's only one bolt securing a clip that holds it into the engine.
I just thought of an issue where the distributor could be clocked to a different position to relieve the pressure on the tach cable. There was a GM Bulletin someone posted on the CF about that. When the distributor is clocked in this way I dont think the wire diagram will align in the traditional way that we think it should. I seem to remember it will be off by +/- 1 spark plug wire position all the way around.
Would this be similar to the question you had about the spark plug wire position in the distributor cap.
Prior owner or whoever did that. Reset new wires accordingly 18436572 stating at 7,
Ok. I've found TDC. However rotor points to # 7 on the distributor. I did not install distributor this way. Prior owner or whoever did that. Reset new wires accordingly 18436572 stating at 7, Dwelled new points and it really runs nice now. Will it affect performance if I leave it the way it is set up? As stated car has a mild cam.
Wow, other than being a little unorthodox and confusing the next guy I see no reason it would have any affect. Someone else may have a different opinion but if you put a timing light on it and get her sit I believe things are golden.
To fix it you would have to pull the distributor, rotate it to position, reinstall, then reset timing... not a huge project. It is amazing that someone was able to accomplish this feat, had to have been on purpose :-)
Glad the information was helpful, I would have never guessed that
Last edited by TX-Techman; Sep 15, 2015 at 09:41 PM.
Ok. I've found TDC. However rotor points to # 7 on the distributor. I did not install distributor this way. Prior owner or whoever did that. Reset new wires accordingly 18436572 stating at 7, Dwelled new points and it really runs nice now. Will it affect performance if I leave it the way it is set up? As stated car has a mild cam.
I just thought of an issue where the distributor could be clocked to a different position to relieve the pressure on the tach cable. There was a GM Bulletin someone posted on the CF about that. When the distributor is clocked in this way I dont think the wire diagram will align in the traditional way that we think it should. I seem to remember it will be off by +/- 1 spark plug wire position all the way around.
Would this be similar to the question you had about the spark plug wire position in the distributor cap.
Prior owner or whoever did that. Reset new wires accordingly 18436572 stating at 7,
kdf
Interesting bulletin. I'm not sure if this was done intentionally to my vette for tach cable issues. I personally think whoever set or reinstalled distributor didn't know factory spec install procedures.
Ignition Problem
