Trouble with my ignition timing

[magnumdust]

Yesterday I spent the day trying to sort out my cars ign. timing issue, but it doesnt make sense to me.

At idle(800-900rpm) with the vac advance plugged it shows 32* then by 3000rpm it would jump to 40-42*.

At idle that's about as low as it will go and still run well. This seems strange considering I was told to set it much lower.

At this point I'm thinking two possibilities: 1. My "new" parts store dist. is set at an "advance" and moves only 10* to full advance? Or 2. The markings on my prof. Products balancer are not right.

 

[Bad Sport]

Yesterday I spent the day trying to sort out my cars ign. timing issue, but it doesnt make sense to me.

At idle(800-900rpm) with the vac advance plugged it shows 32* then by 3000rpm it would jump to 40-42*.

At idle that's about as low as it will go and still run well. This seems strange considering I was told to set it much lower.

At this point I'm thinking two possibilities: 1. My "new" parts store dist. is set at an "advance" and moves only 10* to full advance? Or 2. The markings on my prof. Products balancer are not right.

Have you checked the balancer with #1 cylinder and a piston stop? Have you turned the distributor while watching the timing?

BTW, what exactly are we working on?

 

[magnumdust]

Have you checked the balancer with #1 cylinder and a piston stop? Have you turned the distributor while watching the timing?

BTW, what exactly are we working on?

I have not checked the balancer using a piston stop. I'm gonna order one tomorrow to try it on wed.

I haven't watched the balancer while turning the dist. I would just turn it and re-check it.

This on a 360 magnum

 

[Bad Sport]

If you use a piston stop, it will tell you for sure if your mark is right or off. Then you can go from there.

 

[berlins]

had sort of same issue with mine - think it was something to do with vacuum advance. I bought a rebuilt stock electronic distributor from AutoZone for $40 and put in a spring kit from Summit Racing for $5 and disabled the vacuum advance. With the one spring in from Summit, the dist. is supposed to be full advance at 2400rpm.

 

[my5thmopar]

Hey dust ....I'm not hijacking your thread. I had almost the same issue today. 318, flat top eyebrow and Comp XE256, stock dizzy with Pertronix Ignitor II. I started at 14 and was going to tune and lock distributor. I set idle at 700 rpm. Vacuum plugged. Turned distributor until I got max vacuum at 20". I ended up at 30 degrees advance. I have checked balancer with piston stop. I also checked it during assembly with a dial indicator. The balancer is less than 1 degree off. The engine turns over with no kick back and idles well. When run the rpms up 2500-3k the advance increases another 30 degree to about 60 at balancer. My stock distributor has 30 degree mechanical built in. Not sure what to do. Isn't the aim to get 34-38 total. That means only 4-8 mechanical advance. Maybe someone can jump in and help us.

 

[68dodge]

Do you have a timing light with a dial setting? If you do, set the timing according to the number on the dial timing light you want with the top dead center marking on the balancer at zero on the timing marks. Or you can just disconnect the vacuum advance, plug it, set the timing at full mechanical advance of 34 degrees at say 2800 RPM. Leave it there and see how it runs without the vacuum advance.

 

[magnumdust]

Do you have a timing light with a dial setting? If you do, set the timing according to the number on the dial timing light you want with the top dead center marking on the balancer at zero on the timing marks. Or you can just disconnect the vacuum advance, plug it, set the timing at full mechanical advance of 34 degrees at say 2800 RPM. Leave it there and see how it runs without the vacuum advance.

I picked up a timing light w/ dial earlier today. The piston stop should be in tomorrow and wed. i'll be doing everything i can to figure this out.

Though from what i read, changing the amount of advance on a stock dist. is a big headache involving welding. So i may pick up an aftermarket dist.

 

[BillGrissom]

Turned distributor until I got max vacuum at 20". I ended up at 30 degrees advance. I have checked balancer with piston stop. I also checked it during assembly with a dial indicator. The balancer is less than 1 degree off. The engine turns over with no kick back and idles well. When run the rpms up 2500-3k the advance increases another 30 degree to about 60 at balancer.

Intriguing. The only check you haven't done is verify that your timing light is accurate. I assume you are using one with an advance dial. I have read that many are notoriously inaccurate. One check you might make is to mark 30 deg advance on the balancer and check with a basic non-advance lamp, or could do the same with timing tape.

My 69 Dart was similar. It idled best at ~30 deg advance, and never idled well, slowing way down and wanting to die when you shifted to drive. I also verified the mark with the head off. If I set it at 5 deg BTDC, it would like to speed up in neutral where the mech advance gave it the high timing it liked. It finally idled correctly after I installed a 4th Holley carburetor, so I suspect it was running too lean with the others. Consider installing an O2 sensor. Otherwise, you are always flying blind with a carburetor.

 

[magnumdust]

Looks like it was just the cheapy timing light i used before. This time w/ my new cheapy light, it gave accurate readings and i was able to set/adjust the initial timing.

 

[67Dart273]

There seems to be a HUGE controversy around the www about 'dial up' timing lights. I've seen some that were not accurate, and would just as soon not use 'em. Much easier to check your marks (piston stop) and degree or tape the wheel, DONE

 

[magnumdust]

There seems to be a HUGE controversy around the www about 'dial up' timing lights. I've seen some that were not accurate, and would just as soon not use 'em. Much easier to check your marks (piston stop) and degree or tape the wheel, DONE

Well the previous timing light was just an ancient craftsmen model that my dad got in 197* or so and i just think its not working well anymore.

The new one was one of the dial up lights, and seemed to work ok, but i can see where there can be problems. Especially on one like mine where the dial can be accidentally bumped.