i recently just purchased a 1990 ranger, 2wd, 2.3L standard ranger with 158,000 miles on it. after some repairs to brakes and other components im beginning to work all the problems out of it. the problem i am having now is that it runs good when i first start it up and for about the first 10-15 minutes i drive it. after that, the check engine light comes on. if i drive more than 20-25 minutes the engine begins to stutter at times and when i shift gears. kind of sputters then kicks back on with power. any advice on what the problem could be or where to start trouble shooting

 

First get the codes read. It's a 1990 so you have OBD I . Got a Haynes manual ? It shows how to pull the codes.
Since it runs fine while cold (Open loop mode) and stutters after the engine is warmed up (Closed loop mode) I'm going to say it's a bad O2 sensor or an ignition coil getting hot and opening up inside.

 

we read the codes and nothing came back. but i have located the oxygen sensor and am going to change it out. the problem is similar to an issue i had about 5 years ago in my 1989 ranger with the same engine and an oxygen sensor did the trick.

 

Warner...did changing th O2 sensors help? My '94 ranger runs good for a minute or 2..then runs rough for a minute...then smooths out. Reading my codes was also inconclusive. I had wondered about the O2 sensors, so I'm curious to hear how this went for you.

 

LOL....why do people not report back????

Looks like I will finally have to buy a manual since I don't know how to pull the codes. sigh.

 

It seems to be the norm with people with low post counts.

Try the search button for OBD1 codes. You may have to wade through a bunch of stuff , but i'm sure the procedure is there somewhere to pull the codes.