Can't figure it out...
 

I am new so bear with me. I have a 2002 with 2.3 and 5 speed. Just recently purchased. When mass air flow sensor is plugged in it will NOT run right... throttle is unresponsive...when RPM does pick up and you push in the clutch the engine roars and finally settles down. .Just runs really strange. Stop, get out and unplug mass air flow sensor and your ready to run the Indy! No miss.... throttle very responsive and just runs like a top... for about 5 minutes and then like flipping a switch, runs terrible. Have changed all sensors, found several vacuum leaks... even unhooking all vacuum hoses... nothing changes how it runs. Oh and NOT ONE ENGINE LIGHT OR CODE.

HELP!

Welcome to the forum

2002 Ranger will have the 2.3l DOHC Duratec engine(Mazda L engine), much different from the earlier(1997) 2.3l SOHC Lima engines in Rangers, just FYI

The CEL(check engine light) should come on while driving if MAF is disconnected and set a code for that

Does the CEL work?
Should come on with key on, before starting engine

P0100 Mass or Volume Air Flow Circuit Malfunction
P0101 Mass or Volume Air Flow Circuit Range/Performance Problem
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input
P0104 Mass or Volume Air Flow Circuit Intermittent
There are more MAF codes

P0100 would come up if MAF was unplugged, every time it was unplugged and key was turned on

So you probably have a computer issue
Sanity test for engine computers is to unplug a main sensor, like MAF, and make sure it sets a code for that

I would unhook battery then pull out the computer and have a look at its 104 pin connector, it can have water damage, and open the computer up and look for any obvious damage, there is no "computer test", as Ford doesn't publish those documents
Clean up connector/computer
Then reinstall
See if it works better

Replacing the computer is not that hard, but you do need to deal with PATS, passive anti-theft system
So cross that bridge after the other tests