help with warning light

[RING RACER]

i did have an inkling to the fact that it could well be an injector problem because when my dad started the car for me to look at i noticed that when he revved it, it only went to 4.5 grand on the RPM and so i told him to take it for a blast and see what it or if it could go any higher under load. it did do but i still thought it very odd that when stood idle it would only go as far as 4.5 rpm? is this normal behavior for mercs???

 

[izzi613]

yes they are rev limited when not in gear.