Teacher motivation has only recently been explored in relation to higher education teachers (Sahakyan et al., 2018; Sampson 2016). This is also true for English for Specific Purposes (ESP) lecturers, who teach specialized English in other disciplines. These teachers often face unique challenges, including teaching content outside their expertise, managing students with diverse and often low English proficiencies, and accessing suitable materials. This study examines ESP teacher motivation as a complex dynamic system, focusing on the interplay between affective, cognitive, and contextual factors in determining the motivational trajectories of these teachers over time. Drawing on a duoethnography methodology, the authors, who are themselves ESP teachers, documented their motivational experiences over a timeframe of five weeks in journals. The data were analyzed using a grounded theory approach, integrating qualitative insights with Likert-scale ratings to identify motivational patterns. The findings reveal how cognitive, affective, and contextual factors interact non-linearly to shape motivational trajectories, with shared and individual attractor states influencing fluctuations over time. Despite transient negative states, the teachers’ systems demonstrated adaptability and resilience, recalibrating through self-organization to sustain motivation in response to contextual challenges. The study concludes with several implications aimed at enhancing support for (ESP) teachers by acknowledging the complexity, dynamism, and individual variability of their motivational trajectories.