engine cutting out after high RPM's

[beatass4wheel]

Hey guys, just bought a 1988 ranger with the 2.9l. Took it up to the mountains the other day and it randomly died on me a few times.

I would get the RPM's up to 2500-3000 to climb a hill or bounce up a rock and after I let off the pedal the engine RPM's would drop so far that it just killed itself. Kinda sounded like it was flooding itself maybe?

I was at about 4000-5000 feet elevation, so my first thought was that it wasn't getting enough oxygen for a complete burn? But it is EFI so it should have accounted for that, right? Or is it old enough that the EFI wasn't that good yet?

Also, I am running 31" tires on 3.73's, could that have any effect on the engine trying to work harder to turn over-sized tires and then bogging down after i let off the throttle?

Let me know what you guys think because I am stumped on this one.