I can't get my 2006 Nissan Navara d22 to go past 2000rpm. This issue only started when I changed the battery. I've since changed the fuel filter with no change to performance. Also the glow light only comes on for a slit second whereas before it would come on a bit longer. Auto electrician says diagnostic tool says overheating but it isn't overheating and never has. Auto electrician and mechanics don't know what is wrong