Here's the full story and its long.
I thought it would be a good idea to run vacuum advance on my 406 so that I could reduce my base idle at the carb and bring it up with timing. I have a lillte run-on after I shut the engine off and this set up has worked
in the past with different engines.
I bought a Crane vacuum advance limiter to keep the timing to 10 degrees advance. After I installed it all hell broke loose. Previous to this it was 20 initial and 32 total IIRC. Now my base timing is 1.8 deg and my total is way over 40 and bouncing all over the place. I removed the Crane limiter, set all back to stock and still the timing is buggered. I checked for dirt and its clean. I did find one advance srping missing so I replaced it. All I found of the missing spring is the loop that fits over the advance tab so I figure its still in there but I can't see it. One thing I did notice is the distributor will move aprox 1" at the rotor tip before you can feel the mechanical advance springs start to work. It just moves freely. The engine runs good but I can't get it to idle. Its either 1200 rpm or 600 rpm and it is sluggish off the line till I get the revs up. It's a 5 year old Proform HEI that has never gieven me problems before. Timing chain is new last fall when I installed my new cam. New OTC digital timing light. Sorry for the long post but any help would be appreciated.
I thought it would be a good idea to run vacuum advance on my 406 so that I could reduce my base idle at the carb and bring it up with timing. I have a lillte run-on after I shut the engine off and this set up has worked
in the past with different engines.
I bought a Crane vacuum advance limiter to keep the timing to 10 degrees advance. After I installed it all hell broke loose. Previous to this it was 20 initial and 32 total IIRC. Now my base timing is 1.8 deg and my total is way over 40 and bouncing all over the place. I removed the Crane limiter, set all back to stock and still the timing is buggered. I checked for dirt and its clean. I did find one advance srping missing so I replaced it. All I found of the missing spring is the loop that fits over the advance tab so I figure its still in there but I can't see it. One thing I did notice is the distributor will move aprox 1" at the rotor tip before you can feel the mechanical advance springs start to work. It just moves freely. The engine runs good but I can't get it to idle. Its either 1200 rpm or 600 rpm and it is sluggish off the line till I get the revs up. It's a 5 year old Proform HEI that has never gieven me problems before. Timing chain is new last fall when I installed my new cam. New OTC digital timing light. Sorry for the long post but any help would be appreciated.
