I have a 1994 Isuzu Trooper and since the service the car refuses to start from cold. When you start the engine over, the car will start but the rev's won't go over @ 1000 rev's for around 5 minutes regardless of pressing the accelerator (which has no impact at all) then it will suddenly kick in and rev up. Once going the car is a little sluggish for a couple of mile, even stalling (although it will start straight up when key turned. We had a recall on the injectors around 2 years ago which were replaced by Isuzu, so we don't think it's this but my dozy other half thinks he may have put 15w30 oil in, whereas I've read that 5w30 is the oil to use? Could it be the incorrect oil, or maybe the ORPS? Can anybody advise