Timing woes, I wish I wish I hadn't killed that fish! Options

[mike_the_man]

Hi all,

My car was running like piece of poop recently (74 2.0L with F.I.), but backing off the timing a little made it run a fair bit better. Today I took it for a little drive, got it nice and warm, and decided to try and re-time it. It turns out that my timing was correct when it was running poorly, and now I'm very confused. I checked top dead center on the fan and on the fly wheel, as well as looking at the position of the rotor. Everything points to top dead center. I then put a new mark on the fan at 27 degrees as per the PP tech article. I also found the 27 degree mark on the fan, and it lines up with the mark that I made.

When I rev my car up to 3500 rpm and set the timing to the 27 degree mark (I disconnected the vacuum hose from the dizzy) the car runs like crap. But if I set the static timing (not revving the car up, but setting it at idle) to 27 degrees, it seems to run pretty good. I'm totally confused. Could it be that the mechanical advance isn't working? Is there any way to test the mechanical advance? What would the symptoms be?

I hope this all makes sense, and I'm sorry for the long post.

Thanks for all ideas. A (IMG:style_emoticons/default/beer.gif) to the first person that gets it right.