Hey guys, On this 97/98 MPI 502 I want to know what the voltage range is on the ECT Sensor. its not warming up enough to get the motor out of warm up enrichment mode. If I can put a resistor in line at the sensor then it should fool the ECM in to thinking its warm and would run correctly. I don't have time right now to get the ECM re tuned and don't want to keep taking it out running so rich if I can do this in the mean time.

0-5v

Does anyone know what OHM resistor ide need to put inline? Im guesing ide put the resistor in between the hot and ground in place of the sensor huh? Looks like the yellow wire coming from the ECM supplies the 5 VDC and the other wire is a ground.

Why is it not warming up??? It should have a 160* Tstat.

It's pro charged and has a crossover water system on it. Never breaks 100° and needs to hit at least 105 to come out of enrichment mode. Think I'll try to get a 5vdc resistor with a resistance around 500 ohms give it take.

Hey Will. I will bring down my collection of resistors incase we need them and can figure out the value needed.

Ok cool thanks Rocky! Looking at the temp to resistance values on that sensor it looks like about 1,800 @100 degrees F, 450@ 160 and 185@ 210° so I would assume anything from say 1000 ohms to the 185 would work. Unless I misread something in the computer operating programs, there seems to be a start up program, warm up then hot so it didn't appear that the coolant temp made any changes from the 105 when it comes out of warm up mode to say the high side of 210..

I've got a scan tool so we can make some resistor tests and see what the ECU is reading for temp.

You mean I did all that research for nothing? lol !

hahaha, I didn't know you were posting about it. I have all kinds of tricks up my sleeve, not really, but to work on these without a scan tool is a crap shoot. It's not for nothing, I had no idea what resistance value the ECU was looking for, but I do have a couple hundred resistors that I am bringing down.