What value R7 and R8 for CLT sensor?
 

I know this is an Asked-and-Answered question, but the answers all seem contradictory.

Assuming I am building a standalone 3.0 MS-I, and using the stock 1.6 CLT sensor, what values of R7 (the CLT pullup) and R8 (the CLT offset) should I use?

You keep R7 and use the one that comes in the kit 2.49ohm. Keep the R8 thats in there too.

Ah ha- fast edit there, Sam. ;)

Yeah, this is not a piggyback install. There must be some value of R7, just wasn't sure whether the stock value was best, or some other value.

stock ecu coolant is 2490,
R7 is 2490,

so 2490 for bias when you flash it, since you wont have the ecu in place.

So if I followed Braineacks megasquirt build and am using the OEM ecu to control idle because i have AC, I would use 2490 for the bias resistor for the clt because i left R7 out? This is just to make sure.

Also, for the GM IAT sensor i'd use 2490 as the bias resistor also?

yep.

or if you leave r7 installed, use 4980.

What year is your car supersuk. It seems the 1.6s can use 2490. 96-97 need to use 1205 ohms. Not sure about 94-97. Always leave R7 out in a parallel install.
GM IAT use 2490 with R4 installed.


Fill out your sig sometime.

I'm not sure I believe my own post about the 1205 on 96-97. my coolant temp only reads 65* (is was in the 20s this morning) - 215*. It's not so great for my cold start when the MS won't read below 65*

got a DDM? just check the resistance really fast on the harness.

Thats interesting. Saml01 is using your 1205 and says its only like 8* off what his home thermo says.

Thats funny because my car is a 90 and in order to get the temp readings right I had to use somewhere around 1200 for the bias resistor. I did replace the coolant sensor about a year ago with a part i bought from checkers I think. Think they gave me the wrong part?

Oh one more thing, my GM IAT sensor is about 20degrees off. Its reading that much cooler so i had to offset the linear line by about that much. Now after leaving the car to cool down over night i get temp readings that are about 3-5 degrees off from each other.

No no. The GM AIT is the same as my home thermo, its the CLT thats off by 8 degrees. 8 Degrees to low lower then the AIT.

Tonight im gonna go out and check the readings since the temps are in the 20's.

Did you check your low temp readings? I replaced my sensor today after verifying the readings. It is definitely the same values as the RX7 unit so it's not an easytherm value thing. It has to either be a hardware defect of some kind, or wrong bias resistance. Check yours in the 20-30s and let me know what it reads.

Anyone see CLT go over 215*? Mine never has.

Mine never has either.

Check what in the 20's and 30's?

I have seen coolant over 215. Lots of boost during a 95* day with stock radiator, no shrouding or undertray. My coolant readings are balls on accurate with outside temps though.

check CLT temp... make sure your's reads below 65* when it's cold out. It's warmed up here now so I can't see if my reflash fixed it until the next time I can't start it.

All the time. Last week it was like 20 degrees out and it was reading 8 below the AIT as usual.