i am having trouble with my jeep. it idles rough at times for no apparent reason. i did a bg fuel injection service and changed the fuel filter cause the jeep has 160,000 miles on it. the car was having these issues before i did the fi service. in fact, the reason i did the service was to try and fix this problem. i also removed the iac and cleaned it and removed the throttle body and cleaned that too. any help would be greatly appreciated. thank you