Topic: Tune up - timing
in Forum: C3 Electrical
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Made some progress on my tune-up today.
Background : new spark plugs, distributor cap, rotor and contact point on a non-HEI 74, Quadrajet carb with solenoid and automatic transmission.
1) I adjusted the RPM to 600 (in park) with the vacum plugged. When I put the vacuum back, I get about 900.
2) The feeler gauge wouldn't fit (too wide!!), so I adjusted the dwell to a point where the car would start and then correctly set it to 29 using the meter (again, with the vacuum plugged).
This is where I'm confused : I get about 3 different reading from the timing light. It randomly hits 16, 4 and 10 BTDC. (It should be 10 in my case with a 454).
Am I reading it correctly ? I did not try any distributor adjustment yet. To get to the hold down bolt, I will have to shut the car down, remove the distributor cap, make an adjustment (rotate left or right), put the cap back and try again.
My 2 questions are :
1) is it normal to get multiple reading; concistent on the same 3.
(the light does not seems to flash at a regular internal either).
2) how do I know to turn the distributor left or right and by how much ?
On another note : I am very happy with the progression (remember it is my first time looking under a hood) and replacing all the contact/electrical points already makes a big difference.
Just hope I get get the timing right and get back on the road.
Don't know if it is related, but there is a lot less smoke (at startup) and a lot less smelly emissions now.
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The erratic timing light can be caused by interference jumping from one wire to another. A small amount of this is normal. Try connecting the timing light lead closer to the plug, and away from the other plug wires. Sometime rerouting the plug wire will help. You may have worn out wire insulation.
Thanks for the input Ken.
I think I might know what happened. I will confirm Thursday.
I powered the light using the distributor coil. I think I should have used the alternator. I also have an extra battery that might still read 12 volts, but wasn't cutting it at crank amps. If it reads 12, I will use that battery.
I think the lead wire of the timing light was positioned correctly around #1, but the wires at the cap might have not been set correctly which, I think, could also cause some interference.
I will make sure I get 12 volts to the timing light, set the wires like they should be and test again.
Can you give me a rough idea of which direction and by how much I should turn the distributor if I'm not 10 BTDC? I will probably figure it out by trying, but right now, I have no clue at all.
If you turn the dist in the direction the vacuum advance is pointing from the dist, the timing will advance. The opposite way will retard the timeing. How far will be determined by the reading on the timing light. Make sure the engine is idling slow enough. The mechanical advance can cause you to set the timing wrong if the engine is running too fast.kstyer 38531.9050231481
I'am lovin this, 74-454 has some ball's to try something it sounds like he's never done before, hang in there buddy you'll get it, they make a right angle distributor wrench 1/2" on one end and 9/16" on the other, this might make it easier for you to tighten down the dist. bolt, if you have an inductive timing light some lights require that you put the spark plug adapter facing the spark plug, it should say on the spring loaded adapter "this side towards plug", so far so good, before you can time an engine with a point dist. you have to set the dwell first.
I have set the dwell to exactly 29 (my book says 29 to 31, set to minimum for new points).
I only had to turn the carburator solenoid screw about a quarter turn to get 600 rpm in park with vacumm disconnected.
I might have a chance to go try again tonight using a better power source for the timing light and see if there's a "this side up" on the adapter. This is the one I have; it is inductive.
Thanks anips, I will look for a right angle wrench. That will save a lot of time.
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74-454, that looks like a 'dialable' t-light, meaning you can 'dial in' the amount of advance you want to see. If it is, set the numbers on the light to "10 deg BTDC(advanced)", and then all you have to do is twist the dist. until the groove on the balancer lines up with the "0 deg" mark on the timming tab. (Clockwise is retard, c-clockwise is advance) I love that type of light, because it's so much easier to use. Mine (Crap-On) has a " - " mark on one side of the clamp that goes around the plug wire, but I've never seen any difference in the readings with it either way. 
btw.... If you're getting erratic readings with the light, it could just be a dwell problem, or the dist. might have enough slop in it to cause the points to not be able to keep a solid gap. See if the top of the dist. shaft has a lot of side-2-side movement. You could also have advance weights that are worn, where they fit over the little 'posts' on the shaft. All of these things can be repaired.Adams' Apple 38533.7911111111
btw.... If you're getting erratic readings with the light, it could just be a dwell problem, or the dist. might have enough slop in it to cause the points to not be able to keep a solid gap. See if the top of the dist. shaft has a lot of side-2-side movement. You could also have advance weights that are worn, where they fit over the little 'posts' on the shaft. All of these things can be repaired.
Joel Adams
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Thanks for all the info. I was supposed to do that last night, but I finally received my speedometer cable (the old one not only broke, but melted and twisted on itself; thanks to the headers!) and it took me longer than I thought to replace it. By the time I was done, it was too late to play with the timing. Hopefully tonight.
Is it the actual advance weight that would be worn, or the little springs that holds them ?
The springs are the more likely wear to cause a problem, but the weights can wear at the piviot points and cause some problems as well.
I reset my timing last weekend and my timing light was acting exactly as you describe. Why? Because I forgot it was a dialable light and it was set at "32" when I was trying to get the balancer mark to hit the "12" BTDC mark on the timing tab. Once I hit my forehead with my palm "Doah" and reset the light to "0", everything began working as advertised. Sounds obvious but something easy to check for us newbies.
Good luck
Neil
in Forum: C3 Electrical
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