Can't figure out

[LNL92]

Have a 92 4.0 Liter ranger 4x4. In the last month i have been having problems, one day my check engine light would come on and off. It was running rough and exhaust was smelling rich. I was getting terrible gas mileage. I changed the fuel filter (got tiny bit better) changed spark plugs and wires (got a little better), i put in KN air filter (got alittle better) I cleaned the MAF sensor, it got little better and checked the throttle body sensor (it was fine). Took truck to truck to get codes read, (got a code saying i was running too lean on O2 sensor. So i replaced it got better for a little bit and the check engine light would still come on sometimes. Got the codes read again same code. Put new catalytic converter on got better fuel mileage and power. Still not getting great fuel mileage and check engine light still comes on sometimes. Any ideas anybody? (did a compression test 2 cylinders at 132, 1 at 140, and 3 at 150)

 

[4.0B2]

1. You can read the codes yourself... should be an article in the tech library about how to do this. I'll see if I can find it in a minute.
edit: here you go. http://www.therangerstation.com/tech_library/OBD_I.html


2. check for vacuum leaks.. check your IAC valve, clean it. The IAC has been a big issue with me overall on the 4.0 OHV motor.... it'll make all kinds of codes show up. Check the PCV valve. any of those small things can cause weird issues..

 

[doorgunner]

Let us know what you find wrong next so other members can use your info.

 

[LNL92]

Ok thanks for the help guys. I will try looking into that and going from there. I will let you know what i find.

 

[feellnfroggy]

Sounds like a prob with EGR. Valve stuck open possibly or opening when it shouldn't.