I'm hoping somebody can help me out with this. My '89 740 wagon initially ran very rough when first started, but ran OK after warming up for 10-20 seconds. After a couple weeks, engine began losing power even after warming up. By 'rough', car sounded like it was running on 2 cylinders, pretty much. Car would generally stall if you tried to drive it before the engine smoothed out.

Eventually, car wouldn't start at all. Had it towed to my mechanic, where I'd hoped an hour or less would be sufficient to diagnose, thinking the engine codes might give up the culprit. No such luck. Codes are for O2 sensor and mass air flow meter. Sensor is only a few months old, air flow meter was replaced once, and we tried a new one just in case. Plugs show that cylinders are getting flooded.

Put in a new fuel pressure regulator. Plugs and cap. Recently got new timing belt and tensioner. Timing double-checked and is fine. Ground pulse to injectors is right on. ECU was swapped out for one from the junkyard, at which point car came closer to starting, but still wouldn't. Engine turns over fine, and fires, but not enough to keep running. Next try is to swap out the ignition computer, as well.

Normally aspirated, has crank sensor, which has also been replaced, though quite a while ago. Prior to this problem car ran well.

Any thoughts or suggestions would be much appreciated.


Thanks,
Scott