What to look at, for fixing lopey idle and running rich?

[Supercharged111]

What makes you say it's running rich? Lean exhaust stinks to high heaven and a lean AFR will cause a lope. On the other hand, misfires will make it idle like crap and dump unburned fuel into the exhaust and you don't need a rich or lean condition for that. We need more info here.

 

[0xDEADBEEF]

Check for exhaust leaks upstream of the O2 sensors.

 

[monsterwake]

I just started having a simalar issue. Starts and run fine. I can drive 75 on the interstate. But someimes on excelleration it stalls and goes. I did AC work on it this past weekend so maybe i messed something up with the vacuum. It does this with or without AC turned on. I am worried it is something in my fuel tank. I am going to see if I can check the fuel pressure. I don't have a code reader but I don't get a service engine light.
Plugs, wires, cap, rotor, fuel pump and fuel filter all changed in November. Been running great since then until yesterday afternoon.

 

[monsterwake]

Fuel pressure was good. Replaced the fuel filter and dumpeda bunch of rust out of the old one. I had just put that one in back in November. But, I think my issue was actually my gas cap. I went to add fuel and when I removed the cap, the tank released a lot of pressure.

 

[HotWheelsBurban]

Fuel pressure was good. Replaced the fuel filter and dumpeda bunch of rust out of the old one. I had just put that one in back in November. But, I think my issue was actually my gas cap. I went to add fuel and when I removed the cap, the tank released a lot of pressure.

I'll check the fuel filter too, once it quits raining and I'm off work.

 

[someotherguy]

Fuel pressure was good. Replaced the fuel filter and dumpeda bunch of rust out of the old one. I had just put that one in back in November. But, I think my issue was actually my gas cap. I went to add fuel and when I removed the cap, the tank released a lot of pressure.

Your cap is designed to not vent tank pressure to the atmosphere. That's a smog regulations thing. Sounds like a problem with your EVAP system.

Richard

 

[monsterwake]

I agree with EVAP. My truck is a mud wasp magnet so I am sure something is clogged up somewhere. I just need to find the problem without buying a bunch of parts.
I appriciate all of the info from everyone.

 

[Sean Buick 76]

Start by putting a timing light on each of the 8 spark plugs to confirm they are all firing consistently. Also run the truck in the pitch black with the hood open and watch for spark plug wires shorting out as they will spark visibly. Then ohm test each spark plug wire. Also remove each spark plug and replace if they show signs of cracks or have over 60,000 miles. That would be my first set of tests.