Nissan Repair: 1995 nissan quest, computer control devices, mass airflow sensor

Question
My Nissan Quest was a gift from a great friend. It's a 1995 and it sat about 7 months outdoors with a bad water pump. He said it hadn't over heated and had run fine when parked. When I jumped it and drove it home, about 3/4 of a mile, it wouldn't go above 15 mph and 2500 rpm. I changed the water pump and timing belt. Cars sounds great, idles fine, nice and quiet, no lights on, but still I guess in limp mode from what I have been reading. I read that their are only certain things that will cause limp mode but can't find out what they are. The owners manual talks about a Elcetronic Transaxle Control Module on page 270. The Haynes doesn't even mention a limp mode or causes. My friend kept the vehicle in great repair until it became the 3rd wheel and wasn't needed, hence no urgent repair. Any ideas would be great. Thanks so much and God bless.

Answer
Alan,

First, disconnect the battery for five minutes and see if the codes clear.  Get a Haynes Manual, it has the codes and how to check them if they come back.  Any of the computer control devices can set limp mode.  Now, if the transmission is good, which it sounds like it is the problem is usually the mass airflow sensor or a cracked or loose intake hose from the air meter to the throttle body.  Email me back and let me know what you find.