John Thorne - Photo Credit: Chris Gurton Photography

John Thorne's car has had little running already this season due to the misfire - Photo Credit: Chris Gurton Photography

British Touring Car Championship outfit Thorney Motorsport has withdrawn from the upcoming rounds at Oulton Park and Croft, due in part to an engine misfire that has dogged its season so far.

The team's Vauxhall Insignia has had the issue since it introduced the car at the end of 2011. It tested at Silverstone last week and made progress on handling issues it was suffering, but was forced to end the day early due to the persistent misfire.

The team said it has dropped Swindon Engines as its supplier with immediate effect, though it will continue to use the TOCA unit and develop its own ECU mapping for it.

“The team is gutted, we’ve worked so hard to get to the BTCC, in testing last week we managed to improve the cars handling ten-fold over the course of the day and I was starting to push the car harder and harder which is a huge improvement over Brands and Donington, but this misfire is just soul destroying,” said a frustrated driver and owner John Thorne.

“We come out of Maggots with 6mph more speed than we recorded at the media day then cough and splutter our way up the straight.

“We are stuck with the engine, NGTC regulations are clear on that and our alternative engine will not be ready for this season so we have the choice either to simply withdraw for the 2012 season completely or develop our own mapping for the TOCA control engine, sadly that will take more than the couple of weeks we have before Oulton Park so we have no choice but to withdraw.

“TOCA have been very understanding on the whole issue but consider the matter as one between the team and Swindon Engine. ” added Thorne.