Hey guys, I just bought a 1993 Chevrolet S10 Blazer Tahoe LT with the 4.3 V6 that's running to rich. I'm already in the process of replacing all the sensors since it recently hit 150k miles. Any suggestions on what I can do to fix the problem?

 

I'm not an expert on fuel systems, but a previous experience of mine might help.

I had a 92 and got a check engine light that turned out to be associated with an O2 sensor. I dutifully replaced it, it was covered in carbon, but the problem only came back soon after. I had it checked by a mechanic and learned that there was a fuel leak under the intake plenum that was dumping fuel directly into one side of the intake. The price to have it fixed was way too much so I decided to try to fix it myself. Turned out it was not too hard. If I remember correctly there is something called a "nut kit" I had to get. Basically it replaced the plastic tubing that connected the fuel supply lines at the back of the intake plenum to the fuel injector spider.

Looking at my notes, I did replace the injector too.


Before



After


I forget the label for the engine, but here is a picture of it for identification purposes.