All our crate engines are dyno tested - however, the only time 12 volt battery power is in effect is actually starting the engine. The ignition system is powered by the dyno’s 110 volt AC system which generates a constant 13.7 volts DC to the distributor. If a distributor was defective we would know it immediately and replace it to continue the dyno run. Every engine that leaves here has an operating ignition system. The trouble is usually due to a system in the vehicle which is faulty, such as a poorly functioning alternator, weak battery, poor grounds or an old or damaged wiring harness. Check your system carefully and test for at least 13.5 volts at the distributor before calling for tech help.