The data has been collected by dspace and save into matlab format. Experiment description: This data is to provide information for multiple laser ignition project and prove the effectiveness of dual pulse laser ignition in lean air-fuel ratio. The engine has been run at two different lambdas 1.3 and 1.5 for varying the dual pulse laser ignition effectiveness. For comparing between single laser igntion pulse and dual laser ignition pulse, a series experiments has been taken. The initial single pluse starts trigger at 22 BTDC, then the second pulse has been separately tested at 21, 19, 17, 15, 12, 9, 7, 2, 0 BTDC. Each experiment has around 200 engine cycles. Meanwhile, for comparing the stability, the cov of imep information has been proved. The folder name singlepulselambda1.3.mat and singlepulselambda1.5.mat are the pressures of singlple pulse laser ignition. The folder name dualpluselambda1.3 and 1.5 gives the pressures of different lambda at varying BTDC. The folder name covimepvalue gives the data of engine covimep stability data. Any questions, please contact my email hua.cheng@liverpool.ac.uk