I had a flat spot on throttle application and slight "run on" on throttle reduction with my 20v. It also combined with intermittent periods (several days) of lower power running.
It turned out to be a problem with the HT wiring. One HT lead was open circuit (but still obviously allowing the plug to fire as the motor didn't run that rough) and the contacts inside the distributor cap had a thin oxide coating that didn't conduct well.
After cleaning the contacts inside the distributor cap with a small file (being careful not to file off any more than nesessary of the oxide coating - if virtually flaked off), I got the biggest improvement. The leads were not replaced for a few more days as it took a few days to identify the replacement lead set from Repco (Toyota leads were $290 a set!).
Clearly the spark was not strong enough to get good burn under load (such as when I put my foot down). The higher the load, the harder it is for the air-fuel mixture to burn and hence the better the spark is needed. That is why modern high compression motors have such good ignition systems.
Wed, 02 March 2005 21:17
