87 not warming up

So I have been nitpicking and tuning and playing with this jeep for a year now. Its an 87 wagoneer 4.0. From what I started with it is a completely different animal, however it's still not quite there. First off I have replaced the water pump, thermostat, and heater core. I also replaced the radiator with a new one for a 94 and added a ford escort overflow bottle (its what I had laying around). I eliminated the heater core bypass valve as well. All the hoses are new. The heat has never worked very well, and while all of these changes have helped it is still not that great. I ohmed the temp gauge sender and it checks out. The damn thing will just not warm up. I can't ever tell what the stupid factory gauge is supposed to be calibrated at but I never get over the big line between 100-210. It is also still running rich at idle and getting less than great fuel mileage. Now, the question is is it not warming up because it is running rich or is it running rich because it is never getting out of open loop? I tend to believe the latter. I don't have a radiator shroud or an aux fan on the radiator right now but I will have both soon. I was thinking it could just be massive airflow over the radiator but I blocked it off entirely with cardboard and it still wouldnt warm up. The only time I have seen it get near the 210 mark is when I was stuck in a snow drift and working the throttle pretty hard. The heat was great then!! I was wondering if I could have a partially blocked water passage in the engine not allowing the coolant to flow properly to the head or the heater core but I think I would have other issues if that were the case. I had also considered the clutch fan being stuck and pulling too much air but I would think blocking off the radiator like i did would have nulled the effect.....I was considering removing the fan and seeing what it did. Any thoughts?

What thermostat? Stant SuperStat Premium are all I recommend, and should be 195 degree in the XJ 4.0, I recommend nothing but the Stant and won't install anything but the Stant.

After about 20 minutes of operation you should not be able to comfortably hold your hand around the upper radiator hose. Unless you are a masochist, that is.

Think about it this way--in a Green house the hot water heater is usually set on 120 degrees (mine is 110, but I'm a cheap bastid). Can you comfortably hold your hand under the hot water? Well, your engine should be one heck of lot hotter.

Yeah I just read another post on the cheapo t-stats. I do indeed have the cheapo oreilly's version and will promptly change to a stant. I will let you know if it changes.

It might be helpful to verify your actual temperature as gauge circuits can be inaccurate.

Find a point and shoot infrared laser thermometer. They have really gotten cheap in the past few years, I bought a Raytek mini for less than $50. Great tool for troubleshooting automotive and around the house. Point it directly at the thermostat housing itself. You want to be in the 200-210 range.

I like the Stant Superstat. I also have never had a problem with a stat purchased directly from Jeep and that is where I normally buy them.

As for your running rich/open loop issue, below is a great link to testing of RENIX sensors. The MAP and COOLANT sensors are directly involved in the equation and testing can verify their operation (also be sure vacuum source to MAP is GOOD)

http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

Curtis_H said:

Yeah I just read another post on the cheapo t-stats. I do indeed have the cheapo oreilly's version and will promptly change to a stant. I will let you know if it changes.

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Central Iowa could be pretty damm cold this time of year. I was there from March until December 20, 2007. My XJ would get to just under 200* on city streets. Get on the highway and the temperature will drop to just about 160*. I have the OEM thermostat and no mechanical fan.

Get a good quality thermostat and see what goes from there.

in regards to the running rich issue you can pretty much eliminate any of the sensors or wiring under the hood as every last sensor on this rig is brand new, tested, double tested, re-wired, tested again, then run and tested one more time. Also new are the injectors, alt., intake/exhaust gasket, all the vacuum lines, the EGR valve and transducer, IAC, computer, battery, battery cables (1/0), new cable from alt to bat (4/0), added ground from battery to body, replaced ALL the weatherpack connectors on the loom side of the harness, replaced the metripack connector on the IAC, new distributor, fuel pump, fuel filter, plugs, wires, and exhaust. I have spent quite a bit of time and cash under the hood. I didn't replace everything because I had to, but after testing most of my sensors and finding them on the limits of their accepted ranges I decided that I like this rig enough to just replace everything and have a good dependable machine when I am done. It runs absolutely fantastic really, just rich. Gas mileage could be better as well, but it is as smooth as butter from idle to WOT with plenty of power. No more high idle, rough idle, sputtering, bucking on the highway, no starts, stalls or anything like that anymore. This is just the last of my little issues before I move on to the rest of the rig