Not every bad part is noticeably broken under normal circumstances. Today's post focuses on a performance complaint which the customer described as a fuel injection problem. Everything was fine at idle, but there was a distinct miss under load.
Proper diagnoses is critical to fixing cars quickly and economically. There are plenty of explanations that would have accounted for the customer's descriptions. The right one, however, had nothing to do with the fuel system. The spark plug wire set was several years old, but the car was cleaned regularly. So, they didn't look suspicious.
At idle when vacuum is high and combustion pressures are low, they performed fine. There was a halo of electricity around two of the spark plugs under load. The cause? The spark plug boots were loose fitting and allowing an easier path to ground when combustion pressures were high.
In the end, a little observation made for a quick diagnoses... One that pleasantly surprised the customer too.
New or old, our long history servicing rotaries provides our customers with the right diagnoses on time.