92 240sx auto - runs extremely rich intermittently

[alexh]

Hi,

been working on this problem for months - it is dangerous to drive this car and I may have to junk it if I cannot solve the problem.

Basically, this started about a year ago as a mild hesistation on starting from a dead stop. It has progressed to a very bad hesistation and recently the car barely runs for several minutes at a time. When it happens, it's obvious that the car is running extremely rich - I can see black smoke from the exhaust and I can smell fuel. Strangely though, it always idles even when it's in this mode. Then suddenly the problem completely disappears. The car generally runs great.

I have checked basically every system in the car according to the manual. The last thing I checked was the ECU. I opened it up and it looks pristine - no water damage or discoloration etc. Of course it could be that the ECU has an intermittent failure mode and in that case I may junk the car.

The only thing left that I can think of is injectors - Can injectors get stuck in the open mode? I'm doubtful. I have had injectors serviced/cleaned before on another car and I might try that as a last ditch effort.

Think I'm on the right track?

Thanks

[MaximA32]

If you think it's the ECm, I'd check the classifieds because there are always guys parting out cars from swaps and I'm sure someone has an ECM sitting around for cheap.

[SturgeonGeneral]

sounds like an injector to me. One of my s13's had an injector crap out and stuck open. Could also be one of the injector o rings.