The engine idles rough and the check engine light comes on?

1986 Oldsmobile 98 regency 3.8 litre mileage: 133, 00 KM. When I start the car when it is cold it starts okay and idles for about seven seconds than stalls. The third time I start it it stays running and idles okay. When I drive the car it runs and idles okay. If I shut the car off when it is hot and start it back up in five minutes it idles very rough and sometimes the check engine light will come on. The computer code is 44 - lean exhaust when it is idling rough I take out for a drive and it runs okay. I had the fuel pump changed and same problem. I changed the MAF sensor and same problem. I changed spark plugs and fuel filter six months ago. Any suggestions.