8a8mfh

This is a screen shot of my stock 1993 fan settings using TunerCat.
The fan low/high mph threshold is 0 meaning it doesn't use the high mph fan settings?

8a8mfh

I'm just looking for a second opinion.
To me it looks like fan 1 comes on at 104 celcius, and fan 2 comes on at 109 celcius. And thats the only thing that turns the fans on in this chart. MPH has no effect on fan operation.

It that what it looks like to you?

ps my chip adapter is in the mail so I can't go test this on the car yet.

bjankuski

What this means is that you have the option of setting the temperature of the fans to come on at different temperatures depending on if you are going slow or fast. Currently you have the low to high threshold set at 0 MPH so the fans will come on at the high mph settings of 109 C. and 113 C. If you set the low to high MPH threshold at 35 MPH the fans would come on at 104 C. and 109 C. at speeds below 35 MPH and 109 C. and 113 C. at speeds above 35 mph.

You can use this on the highway to turn yours fans off at speeds above lets say above 50 mph because at 50 MPH you should have enough ram air to keep the car cool. To do this move the fan temps up to the highest setting you would want to ever want to see at the high speed settings and move the highway threshold to 50 or 55 mph.

8a8mfh

I see now, it says for speeds less than this value the low mph settings will be used. Theres nothing lower than 0 so it has to use the high mph settings.

BTW this is the factory eprom, BDBK broadcast code, in my '93. 1st read before I modified anything.

pkincy

Interesting. I am away from my computer, but will check my stock and several modded bins to see where they set the low/high constant chang when i get to my computer tonight and will report back.

I would think something in the 40-50 mph range would make sense.

I quite often make my fan on/off temps the same and generally much lower than stock. My 93 Y Bod cruises at 77 F. That is with a built 383.

pkincy

177 F, sorry

pkincy

Interesting, the stock file I have for a 93 is also 0 mph, as is most of the tuned files I have done as well as one file that I have from one of the well known OBD1 tuned chip providers.

So only the Hi MPH numbers are used normally.

8a8mfh

Thanks for checking that out, I appreciate it

I noticed on TunerPro the values are slightly different,,,, like 108.4 while tunercat says it's 109. I hope no other tables are like that, like fueling, etc.
I'm doing the most basic of all tunes. Shutting off egr and air, adjusting fan temps. But if I load the stock calibration off the eprom, make the changes above and load it back on a chip everything should be exactly the same right? Except for what I changed.

Maybe I'm worried too much, my only experience in "making" things that weren't preloaded in the software is when I used HPTuners for a 2002 f body. I used the factory not used egr part of program to connect a wideband, in doing this I realized a .2 or so has a huge effect on the actual reading. A lot of people were doing this at the time so help was available.

See I'm not even sure if that paragraph makes sense to anyone else

pkincy

The file should remain the same except for the few values you change

8a8mfh

Thanks, I just got the chip adapter in the mail. I know I'm not going to see much if anything, but....

I do appreciate the help.

8a8mfh

Well it drives around the block ok, the placebo effect is amazing! it's so much faster!!

Seriously though, it does run smoother without that blown out old egr valve on it.

FWIW the dash gauge shows the low fan turn on 1 degree higher than the program and it shuts off 3 degrees lower than the program.

Heres how that part ended up. I really wanted to tune the other stuff, and when I realized I could do the temps it took me forever to decide. I still don't know why I didn't keep this stock. But it only cost me $60.

Cliff Harris

Be aware that the coolant temperature sensor used by the ECM/PCM is not the same as the CTS used by the dash so they will never agree exactly. I've heard that they are usually about 10 degrees different. I never checked. I go by what the tuner program is showing because that is what the ECM/PCM is using.

You need to watch out for false precision. 8 bit binary numbers only go up to 255, so the ECM has to cheat to get the numbers to fit. For example, RPM is divided by 25, so the smallest increment will be 25.

8 bit binary numbers do not have fractions, so any number with a decimal point was calculated by the scanner program and is not what the ECM/PCM is actually using.

8a8mfh

The digital readout must somehow come off the same sensor that the ECM uses. When I got the car the end of the sensor in the cylinder head was broken off and the needle gauge didn't work. It ran fine and the digital readout was close when the fans came on (for an example).

I firmly agree the needle gauge is nowhere near close, but its easier to see. I dug a sensor out of my collection and installed it.

As for the the other stuff, I do know what you're refering to since I bought the Moates APU1 with TunerPro RT 8 years ago. I was dissapointed to find most of it very basic unless you wanted to get into binary programming to add more parameters. I was used to using HPTuners at the time.

I think if anything I was happy to dust off the old APU1 because I could use it again. But I knew I wouldn't be doing much, the car is going to stay stock.

But getting back to what you were saying Cliff, if the scanner program reads a little off thats just how it appears on the screen. If I just read the chip side of the eprom, made basic changes, and burned it back to a chip everything else would remain identical? Like what pkincy had said.