1999 Ranger

My Ranger suddenly ran very rich then the check engine light came on - diagnosis was the ECM (computer) was dead - had it rebuilt and the engine ran for approx 10 minutes then ran very rich again. Tried disconnecting the Air flow meter and it made no difference - the check engine light is back on - any ideas on what to do next would be extremely welcome.

I have never had any luck with rebuilt "anything". I have learned to buy new parts. It's still alot cheaper than a new vehicle.

- the check engine light is back on - any ideas on what to do next would be extremely welcome.

What are the trouble codes from the check engine light. I have worked on Fords for years and have not seen that many ECM's fail. Usually it is a wiring problem somewhere else. Post codes and we can help.

running rich usually is the coolant temp sensor or oxygen sensor's

running rich usually is the coolant temp sensor or oxygen sensor's

Here's the NOW situation. From cold the engine runs smoothly. Hold it at 3000 rpm and after about 5 minutes it suddenly drops to 2200 rpm without assistance and black smoke pours out of the exhaust. Then the check engine light comes on about 5 minutes later - HELP