The late 80s TBi either worked well, or it worked very poorly. If it worked poorly, since it was "new technology", everyone heard the horror stories, but few every heard (or cared) of how many worked without issues. The truck guys were much worse then the car guys, most didn't like the lack of carbs, or the "computer" at all, in any form, couldn't patch it up on the side of the road was the most used statement. Funny thing, I don't remember having to patch up many Mopars on the side of the road ever, unless I broke something by abuse.

Performance was pretty lame during that time (late 70s & early 80 lean burn HP applications, anyone?), the EFI was "very new", (introduced in 88/89, pretty much across the board). Most factories made yearly updates to improve performance, but offered very little in the "adjustment" the computer process.
At Chrysler at the time, more performance was adding turbochargers to the cars, but the truck guys were stuck with what they could get from Mopar Performance (or was it still Direct Connection at the time?). Chrysler was offering the 75K miles full drive train warranty, so the last thing they wanted was someone messing with their tested computer settings.