Quote Originally Posted by EagleMark View Post
I'd like to hear what timing is with/without bias, will be a shocker to people!

The oil burning can really mess up an 02 sensor reading.

Most people couldn't find a vacuum leak if you told them exactly how to. Carb and choke cleaner does not work, brake clean does not work, even nowadays something has changed in starting fluid and it does not work where old starting fluid was fantastic! But spraying flammable fluid around an engine is not a safe procedure anyway... I'm back to propane soldering tourch and a long rubber hose. It's about half as good as old starting fluid. So harder to hear engine change when propane finds vacuum leak, even harder if it's a big vacuum leak because engine is running so bad you can't hear/feel a change. There was a home made way to make a smoke machine I read somewhere. At first I had a laugh at how they made it, then anyone who tried and improved the build all had great results.

No your not going to get 30 degrees advance at idle without a large cam/low vacuum, that is the indicator. The only reason it works on large cams is the overlap and exhaust gases getting into fuel air mixture at idle. EGR effect. As soon as engine increases RPM and flow is returned the high advance used to make it idle needs to go away! Your truck should be fine at 20-21, you already proved 25-26 is max and getting worse, this proves the 4-6 degree retard when finding detonation.
slight derail here.... but you can get cylinders of starting fluid that your propane soldering torch head will screw on to. These are the cylinders made for ether start systems for diesel equipment. It works better than any starting fluid in a can than I have been able to find.