Hi- I have a '79 with stock points distributor- I adjusted the timming as specd in the manual for the leading plugs but when I switched to the trailing plug wire- it was firing at the same leading "yellow" timming mark on the pulley (pulley has two marks- yellow-leading and red-trailing)- according to the manual- I moved the trailing vacuum unit to advance or retard the trailing timing but there is no change? please help!!!

 

Is the trailing timing the same as the leading?- does anyone know?

 

I'm not an expert, but I just got a '79 about 2 weeks ago. I think you have to set the dwell angle to 58 degrees +/- 3 degrees. Then you set the points according to the stock timing marks on the pulley. I'm really not sure that what I'm telling you is right, but based on the Haynes manual I have, it seems about right. Sorry I can't help more. Good luck.

 

the trailing ignition sucks anyways. advancing it can only help with your power/economy.

but it seems odd that it would fire exactly when the leading fires... are you sure you're testing it correctly?

 

Check the vacuum line for the trailing unit. Vacuum test the trailing unit valve. While the valve is off, push/pull on the arm and see if the trailing timing changes.

 

Thanks guys- I removed the vacuum line to the trailing valve & there was no change in idle rpm? should the idle change or be rough?

n0pistons can you tell me the correct gap for the points from you Hanes manual?

thanks again guys! I will troubleshoot this again tomorrow.

 

With inductive timing lights, sometimes they will pickup the leading signal even when connected to trailing. Try to move the pickup close to the distributor cap or try a different light. Good luck.

 

check that you are not triggerig your trailing coil with your leading point set