Engine won't rev past 1700 RPM's

[GKS]

My friends in haiti have a diesel mazda bt 50.It won't rev past about 1700 rpms. fuel filter is new. i think it's not getting fuel...anyone knw about these things? Any ideas?

Someone said maybe an O2 sensor...i dont want to just start replacing parts...help please

 

[GKS]

whew! this post turned out to be Great! all the help, ideas...I can't thank you enough...We got it fixed! great ideas! Lot's of help! I know where to turn when I need Mazda help!

Thanks again. I hope my explanation of the problem was as helpful as the replies I got!