One problem related to engine stall has been reported for the 1999 Ford Ranger. The most recently reported issues are listed below.
My 1999 Ford Ranger 4x4 with 3. 0 liter flex fuel engine began sputtering, running rough and overheating two days ago. I took it to haldeman Ford to be checked. They told me today there was water/coolant in at least one of the cylinders and the head(s) may be cracked, and I need a new or rebuilt engine. The truck has just over 95,000 miles on it. I had oil changes, coolant flushes, etc. At regular intervals. From what I have read on your website, and heard from others, this is a problem with the six cylinder engines Ford used in Rangers and explorers. They said it would be $6400 for a rebuilt engine installed. It seems this is most likely a manufacturing defect, but the folks at the dealer said no.