OK so I got a 94 ranger 2.3l manual and cant get the damn thing to get to normal temp. So my truck stays in closed loop mode and now I cant pass smog because its not opening the EGR valve. Does anyone know the resistance that the TEmp sensor is supposed to give. I am just going to put in a resistor to atleast pass my smog. As for long term I guess Im going to try and change out my t-stat again. I did it once but maybe i didnt do it right and its leaking past. Well thanks for the help.

 

I will just add this little bit of exerience, and then disappear from the forum. Just finished a too long trip searching for the answer to water temps being a bit too high in summer, and far too low in 50 degree weather. First found out the water temp gauge was inaccurate. Replaced it. Then found the problem of not going above 150 degrees with ambient of 50 degrees. Finally decided something was going on at the thermostat. Either it was leaking around the thermostat housing, or it was sticking open, or not completely sealing. Best guess is it was a combination of all three. Found a little galvanic corrosion on the face of the aluminum intake, which would result in some coolant getting past at that point. Also found pitting and poor fitting of the stat in housing. Then noticed the cheapo thermostat didnt completely seal even when closed. Checked the stat's opening temperature and it began opening at 172.
So, bought a Robert Shaw all brass and copper stat, after doing a lot of searching to find one. Replaced the thermostat housing and sealed the corroded area on the intake where the steel bodied thermostat had been in contact with the aluminum.
Final outcome is yet to be seen, but if all of this doesnt work, it will have to be the cardboard in front of radiator trick for winter driving.
Maybe some of this will be useful info for a 4 cylinder. My motor is a 1956 Ford292.

 

Thanks for the input Mike. I think you're pointing in the right direction, I too suspect thermostat problems.

Prerunner, the modern Ford EFI engines are designed to operate at around 195º F, many people don't realize this and put in thermostats that are too cold thus causing the problems you describe. Also, there are so many cheapo thermostats available that a lot of them are bad right out of the box, or quickly go bad. Most simply stick closed causing overheating, but some stick open causing underheating. I'd yank that puppy and replace it with a Stant SuperStat or some other good T-stat rather than go messing about with resistors.

 

i've already tried changing the tstat and it didnt make a difference. My engine just runs to cold for some reason. Even if I put cardboard in front of the whole radiator it still never warms up. Even if I feel the radiator after about a 20min drive on the freeway with the cardboard the radiators still cold. So im done messing with it. Nobody knows the resistence of it. Also whats the fuel pressure suppossed to be. I think I might test that next. thanks for the help

 

Fuel pressure should be 35-45 psi.

 

so nobody knows the resistance of the temp sensor. nobody??

 

The resistance of course varies due to temp, check this out and see if it's of any help, there's a chart at the bottom of the page:

http://fordfuelinjection.com/index.php?p=28

 

ok I put in the resistor and got some more codes. Now I have code

72-insufficient manifold vacuum change detected during dynamic response portion of engine on self check.

32-EGR valve position (EVP) sensor or pressure feedback egr (PFE) sensor signal voltage is below closed limit or has gone beyond set limits.

65-engine control system never went into closed loop fuel operation

38-Idle tracking switch (ITS) circuit open.

I also checked the EVR solenoid and got these specs

at 800rpm i got 46kohms

at 2000rpm I got 53

and at 3000rpm I got 63

Does this sound right. I dont have any pressure on the egr valve at all when I rev the engine but have good pressure to the evr valve

Please any help is greatly appreciated. I havent been able to use my truck for 2 months b/c I cant pass smog. I would take it to a mechanic but got no $$.