Ok, help diagnose this rich running please

[ARSmay]

Now that I finally have the parts money to throw at the thing, it's time for the definitive "diagnose the rich running 3fe" thread.

Lets start a to do list of everything it could possibly be. I've got the idle screw all the way adjusted 'slow' and it still idles at 800 give or take when hot. I have an exhaust leak right under the drivers door that will be getting fixed, and I'm wondering if o2 sensors would be a good idea to replace before I mess with anything else.

HIt me with some ideas!

 

[RockDoc]

A search of the 80s section will net lots of opinions on O2 sensor replacement. They will throw a code if they are really out of whack, but there is a fair bit of leniency in the system from what I understand. The FSM details how to test (within the range of error) the function of the sensors. If you are running rich and getting poor milage, the O2 sensors would be high on my list of potential causes.

Other things I would wonder about are the AFM (the air part of the air/fuel ratio), fuel pressure issues, and perhaps injector or injector control issues (cold start injector remaining on after warm up?). My $0.02 having never dealt with any of these issue personally.

 

[ARSmay]

Thanks RockDoc, I also forgot to mention that I have replaced the fuel pressure regulator.

 

[RockDoc]

Do you have an FSM? It may have good trouble-shooting in it, but I am away from mine right now.

 

[cruiser88]

Check for codes.......pull the intake off clean the EGR and the works.....i promise you it needs done.

Adjust valves

02 are preventive maintenance so i would swap out

That would be a good start