coolant temperature sensor renix replacement 4.0

[a bum with money]

my mj is getting lousy mpg, and hard start when warmed up. I have the renix engine monitor v2 and going through the check list of readings everything checks ok except the coolant sensor ( engine block ) temp doesn't move above 104 degrees when at 200 =/- degrees warm, also its in open loop and running rich. doesn't look too easy to get to behind the left engine mount. before I go through all that work to replace it is there a way to test the sensor while it's still in the engine?

 

also is there a best, better, or worse brand for this animal? part #'s would be great.

 

also is it possible to upgrade to the H.O. system w/o doing a complete renix to H.O. swap?

 

1988 MJ 4.0l, AT, 2WD, no A/C

 

thanks

Bryce

[89 MJ]

1 hour ago, a bum with money said:

also is it possible to upgrade to the H.O. system w/o doing a complete renix to H.O. swap?

 

You can switch to an HO throttle body, but I believe that is all you can do before doing a full HO swap.