1992 Ford Crown Victoria DTC 189 rich adaptive limit reached /system lean

Your 1992 Ford Crown Victoria could be showing a DTC 189 for several reasons. The problem is simply a lack of fuel reaching the combustion chambers. You want to look into things which would restrict fuel delivery such as dirty fuel injectors, dirty fuel filter, low fuel pressure due to defective fuel pump... the list goes on. These are just a few of the mechanical faults which can cause low fuel delivery (lean fuel) issues. Once these components are inspected for proper operation, the diagnosis should continue on to your Ford Crown Victoria's electronic sensors.

Defective fuel feedback sensors will disrupt fuel delivery as well. Our best recommendation would be to allow only a smog check repair certified mechanic inspect your vehicle for a lean fuel mixture problem.

One important diagnosis point we should mention however is since the problem appears to be teprature related you may want to inspect the ECT. If the ECT (coolant temperature sensor) is not operating properly (not sending the correct voltage signal to the Engine Control Module) the ECM will not be able to properly calculate how much fuel to deliver to the combustion chambers. When the engine is cold the ECM is programmed to deliver a richer fuel mixture (more fuel). As the engine warms up, the ECM will lean out the mixture. Insuring the ECT is sending the correct voltage to the ECM is important for correct air/fuel ratio (optimum is 14:7).