I just sold my 85 bronco, and I am going to look at a 1991 4 door bronco, with a 7.3 IDI.

I have never owned a diesel before, and I am not sure what to inspect. It has been parked since January because the starter went out. What should I be looking for, to make sure I am not buying something with a bad engine?

 

Better assume the worst and adjust the price accordingly. A guy who parks a truck because of a $150 and 3 bolt job isn't the type to perform regular maintenance.

 

Make sure it turns over by hand. 15/16 deep socket and breaker bar works(or regular socket+extension)

 

They're pretty solid... check coolant color and condition, oil for coolant, look for leaky head gasket, etc.

I'd have him put a starter on if you're weary...or at least have him buy one and install it yourself.

 

+1; he either should have replaced the starter when it failed, or put the vehicle up for sale at the time. Definitely a major bargaining chip.

The other elephant-in-the-room question is, what exactly is this thing? It's obviously not stock. So is it a Bronco (i.e. half-ton) that's been stretched and an IDI dropped in it? Or is a former IDI truck (i.e. 3/4-ton or up) that's had a custom Bronco body dropped on it? Or some Island-of-Dr-Moreau hybrid of the two? You'll want to know the provenance of this vehicle in as much detail as possible -- frame, suspension, powertrain, drivetrain, build process, etc.

 

If you can't hear it run, treat it like locked up junk and pay accordingly. Just because it turns does not mean that the engine wasn't run out of oil and spun the mains in the block (=ruined). Ask me how I know Even if the engine is fine, non-running condition might be hiding worn out IP and injectors (~$1,000) bad glow plugs (~$100) or pesky air intrusion problems in addition to all the regular automotive things that you cannot check without starting the engine and driving the vehicle. I know how rare these are to find (and to the poster who asked, the 4-door Bronco is an F350 crew cab converted by the Centurion company... they are legit)... so a dead engine isn't necessarily a deal breaker. It would be well worth finding a running drop-in if needed. The guy just can't expect full price without it running.

 

The C350 (custom 4-door Bronco body on an F350 CC frame) is widely known. There's no evidence that the vehicle in question is one such, given that a LOT of DIY-ers have cobbled together similar vehicles. And the OP calls it a Bronco, when there is no such marking on a C350.

In any event, neither one is stock. And the C350, however "legit", is not exactly a premium quality build, given that they didn't do jack about the fact that the wheelbase of the CCSB frame is totally wrong for the body. Throw in the questionable running status of the powertrain and its recent non-service history, the truck (?) is a conversation piece at best.