We had an Allen scope/analyzer with tailpipe sniffer for years which was OK for passenger cars but a miserable failure on race cars (sprint, super modified). An old timer whose cars ALWAYS were kick butt saw my struggles and solved my problem with the "wet pant leg" approach. He said to fatten the mixture till raw alcohol exiting the collector would make my pant leg wet and then lean it till the temp just started to rise. No more flame from exhaust or injector tubes and several season championships later I was a believer. All this to express that sometimes working under driving conditions is a better approach than hooking to a machine.
