Rough idle/check engine light

[TomsAero]

Ok, so i put a new engine into my van(1993 4WD, 4.0L). It has always idles rough since i baught it about 6 months ago, but now the trans went, and the morons at the shop are trying to tell me they cant set up the trans because it idles rough. Anyway, the check engine light keeps coming on then going off, so i checked the code and it said it was the throttle body temp sensor. I replaced that, it ran smooth for about an hour, then it went back to its old self. Well, now the check engine light is back on(comes on, then turns off, comes one...), but when i check for codes, i get nothing. Tomorrow i am replacing the engine temp sensor(for some reason the temp gauge works sometimes, sometimes doesnt since the old engine exploded).

has anyone had anything like this happen to their van? any ideas on the problem?

[TomsAero]

Problem solved. It was the MAF sensor. It only took replacing every sensor to figure that out. Oh well, now she runs like a champ.