4.0L overheating and running lean

[plainsranger]

When you put in the electric fan, did you use the fan shroud?

 

[parkrangerjeremy]

yes the fan came with a built in fan shroud

 

[AllanD]

Systematic component replacement with used but "Known Good"
parts from another vehicle is as valid a diagnostic proceedure as any...

Infact when you've got a problem and it MOVES to the other vehicle
you have proof positive where the problem lies...

AD

 

[parkrangerjeremy]

yep exactly and it cuts down diagnosis time by alot... still haven't figured anything out really hooked up a scan tool and watched the live data and everyhting seemed to check out ok and the timing was at about 18 degrees advance so still trying to diagnose this issue

 

[weirdunclespongebob]

Please let me know what you find. I'm having the same problem with a 94 B4000. Everything is new (including 2 row radiator) and the thing still heats up under load.

 

[parkrangerjeremy]

ok will do ... hopefully this weekend i will have it figured out its really starting to make me mad lol

 

[parson2008]

So what was it? Im having the exact same problem.... thanks
Nu

 

[parson2008]

any luck on finding out what was wrong?

 

[ronclark]

i just started having my truck overheat. it doesnt sky rocket it just slowly starts going higher and higher while i am driving on the highway... when i let it sit there and idle it starts to slowly come down which doesnt make any sense at all. I checked to make sure the water pump is circulating water which it is and the thermostat is also opening and my radiator is clear. i pulled the spark plugs to check the compression and i have good compression the only weird thing is the are white and showing i am running lean.... i hae been also getting real bad gas mileage and it also smells like it is running rich which really confuses me...any ideas what could be going on??? thanks in advance

I am assume you are working on the 93 you have in your bio.
before you spend anymore money i would read this
http://www.therangerstation.com/tech_library/OBD_I.html
and give us some codes.
Once you have your codes, work on the lowest number and work your way up as you fix each code.

 

[Kona]

Head or head gasket........