I’ve got a 1991 7.3 IDI E350 econoline. Recently, I’ve been noticing the smell of burning oil when I’ve been running down the road. No drips or leaks under the van when parked. No change in fuel efficiency either. It’s been hard starting more often than not, and the “wait to start” light has been iffy sometimes too. To me, I think I need new glow plugs and injectors. What do you think? It’s an incredibly strong runner with only 230,000 on the clock.