Hello, this is my first post but spent the past 5 days searching the forum for most of my answers.
Anyway, picked up a 1985 with an automatic and 103,000 miles 5 days ago and have a few questions that I couldn't answer on my own.

1) The car runs right about 160* while moving and going up to 203* stopped. Would this indicate a 160* thermostat? I haven't removed it yet to check but why would a 160* be used in place of the 195*?
Is the 195* the correct one?

2) The cooling fan on the engine side of the radiator comes on at 203* and goes off at 175*. It is my understanding it should not come on until 235*. Could the sensor that triggers the fan been changed?
Is this the only cooling fan?

3) Pulled the spark plugs, that were recently installed, and they are AC-R43TS, the Haynes manual (yes,Iknow) calls for AC-R43CTS is this going to be a problem? Gaps were set to .035 as per sticker under hood that says the spec has been changed to .035 gap.

4) Can I do the minimum idle/tps adjustment with the engine running around the 160* ?

5) Is there a way to visually confirm if an other than stock chip/prom or whatever there called was installed?

I apologize for all the questions as I am waiting for a FSM to arrive but I was hoping to get some things figured out in the time being.

Thank you.

 

It sounds like the thermostat was replaced and the computer was tuned to make the fan come on faster. If you pull down the computer, take a picture of the chip inside the computer. There should be a little cover that has 2 bolts on it on the side of the computer, the cover is about 2" x 5".

With my computer on my '85, I had to cut the computer holding bracket so the computer would fit in place because the chip protrudes out more than the factory chip. I also was not able to re-install the 2" x 5" cover because of my chip.

Remove the cover under the passenger side dash board, the one that is directly above the passenger's knees.

If you look up in there, there should be a yellowish box in there. There are 2 10mm bolts. Remove them and the computer will slide out.

 

I think the CTS are copper core, no biggy. The .35 gap is right, even with a hot coil. You might have a replaced temp sensor that's setup to get the fans on at a cooler temp. I think you need the min idle at 180 +. Welcome to the 80's.

 

That 30+deg will give more power and some people (self included) prefer the engine to run cooler.

I run 160 deg year around and have no issues with setting IAC & TPS. I like to set my TPS at 0.65Vdc instead of the factory 0.54Vdc for little snappier throttle response.

 

The L98 will run at about 160 degrees if you have no thermostat ,
I like my car to run cool too, but my chip goes into its final closed loop tune at about 180 (its actually 81 celcius which is a bit under 180) so I run a 180 thermostat and everything is good.

You have 2 fans, the first one should come on at just over 195, so that sounds about right in your car, the second higher (around the 235 you mentioned)

just be aware that talking thermostats and fan settings seems to set off some "spirited" conversation on her for some reason

 

I almost started it going when I read the op say it should not come on before that temp. Any thing I ever saw just said on by that temperature.

Not really trying to start it but where did you hear it should not come on before 235.

 

welcome to the forum....I have an 85, quite a few regulars do too....getting a fsm is a good thing....you'll be needing it....when you post, always tell your year....searching threads , as you have indicated, will answer a lot of questions without posting....the 85 had iron heads so i'm thinking cooler the better.....I replaced mine with aluminum heads...still run 160, have the fan on at 175......aux fan is on a manual switch...otherwise it would never come on....i think 228 normally.... normal temps for your car can be 220-230......won't hurt, just scares you....most of us old school guys have cooled them down, but you don't have to if you don't want to....have fun....it's a great car....

by the way....daniels directions for removing the chip was exact but he left out the part about twisting like a pretzel to get at it.....

 

You have a modified chip in your car. Maybe this one....
http://www.ebay.com/itm/STAGE2-CHIP-...-/130207926555
I remember I needed to get a 165 degree thermostat. Cooling fan goes on earlier, like 185.

 

I had a chance to poke around on it today and I discovered that the sensor that is between spark plugs 6 & 8 had a single wire connector tucked on the side and a double wire sensor that has a blue and a green wire coming out of it and going to the wire harness by the battery where the blue and green wire both tie into a factory green/white wire. There is also a relay connected there that the PO said was some kind of aftermarket fan relay.

Is this what is turning the fans on at a cooler than factory temp?

If anybody understands what I have going on here I would appreciate your input.

Thank you.

 

Hi local2ed

You should have a 190f or 195f thermostat, the ecm will turn on the cooling fan at around 220F.

Do you have the booster fan option? that uses a temp switch on the passenger side head, to run the booster fan at around 230f that is independant of the ecm.

The cars without the booster fan used that temp switch as an emergency overide i believe.

Now you do not need to get your chip changed, just fit an adjustable coolant fan switch, see below what it looks like. You can get them a lot cheaper.

http://www.ebay.com/itm/DERALE-ADJUSTABLE-FAN-THERMOSTAT-32-F-240-F-WITH-RADIATOR-PROBE-16769-/161045763030?pt=AU_Car_Parts_Accessories&hash=item257f1353d6#ht_3829wt_696
Once youy have one of those, you can set the coolant temp to what ever temp you want to run, i have mine set to turn on the cooling fan at 190f. Works great and easy to fit.

Just run a wire from the frame to one contact and the other contact you run a wire to the green/white wire that goes to the cooling fan relay terminal B, the green/white wire that the ECM grounds to run the cooling fan.

See cooling fan wiring diagram below. Simple hey
You can see my adjustable temp witch below the top radiator hose in the last picture. That way you keep the standard fan relay wiring.

 

they actually sell manual fan switch setups but its just as easy to buy a simpy dble pole switch at ace, ground the middle pole and run a wire from both sides of the switch to the green wire coming out of each fan relay..assuming you have the aux fan too...then you can turn one or both on when you want.....wouldn't cost 5 bucks....

 

You are correct about the 160*. I found out the thermostat that was in there was a 180* but was stuck open.
Replaced it with another 180* and the temp. swings are way less and the fans seem to work just fine the way they're set.

In all my years wrenching I have never had a thermostat stick open.
Is this a fail-safe mode?