Coolant temp sensor mod (old trick could work?)

[Statik]

Hey guys,
My brother-in-law owns a 1996 accent(AKA:brio) and one of the many mods he has put in is a potentiometer (I think its 10K range) on one of the lines that plug into the coolant sensor. With this mod he can make the ECU think that the engine is below operating temp. which in turn the ECU richens the A/F mixture..
(sorta like when you drive the XD in the morning but then bogs down once it gets warm.)
You guys think this will work for our XD's?
I know that supposedly our cars already run rich, but its the only thing that explains that extra power that I feel in the morning.
I will be the guineapig for this mod anyway. I'll let you guys know if I feel anything different.

[FordFasteRR]

well, honestly... I dont think you will gain any power by doing this mod.

In fact, running overly rich will reduce your power output.

Last week when I was on the dyno, I tested my air fuel ratio 3 times..

#1. Stock map setting...11.4 a/f ratio = 128.5 whp.. (very rich and safe)
#2. -4 on the fuel tuner.. 12.1 a/f ratio = 130.2 whp (that is + 2.x whp ! by going 1 point leaner) (still rich and safe)
#3. -8 on the fuel tuner.. 13.3 a/f ratio = 129.8 whp (that is a loss of 1 whp by going TOO lean..) ( too lean, not as safe... )

so my point is that the car responded to leaning out the a/f ratio on the top end... so doing this mod of hacking the temp sensor is only going to yield less hp and carbon deposits due to running to rich..


Save your time on real mods :) Get a blower or a turbo or nitrous and have yourself a ball !

[azwildfire]

http://www.hmaservice.com/webtech/iindex.asp?id=394891514#_394891514

short answer. no. the reason the other car runs rich is because the ECU stays in OPEN LOOP mode until the coolant temp reaches operating figures. this is common on most obd-2 vehicles ...

however our ECU waits a bit of time and if the temp never changes, it sends an Error code and says *hey! fix the temp sensor damn it*

[FordFasteRR]

:phone: ......................

however our ECU waits a bit of time and if the temp never changes, it sends an Error code and says *hey! fix the temp sensor damn it*


I dont know if that will happen.. since the signal will change, only difference being that it will read a constantly lower temperature.. as if the outside temps were SO COLD that the coolant never reaches typical operating temperatures.. just on the lower end of the operating temperature... as long as the resistor is installed _in_line with the sensor, it will still send varying voltages to the ecm.

[azwildfire]

using obd-2 readers while tuning my turbo... my car stays between 190 and 210 ECT

i am in arizona so imagine that it is on the high end of heat if anything, however the fans dont kick on till 205°f and kick off at 195°

so my guess would be... anything lower then 190 blah blah and the ECU wont like it...

however, how much fuel can the computer POSSIBLY adjust based on 10-20 degrees of Engine coolant temp?

[FordFasteRR]

not much... in reality its only adding enough fuel for the engine to run smooth when its cold...

it also pulls timing which can lead to the engine feeling "smoother" when you hit the gas..

in actuality, you should not be pushing your car hard when the engine coolant is cold, otherwise you could cause premature wear of the metal surfaces inside.

[Statik]

Ok... scratch that idea of the list..... back to the drawing board...

Hey ford, you wouldint happen to have a spare nitrous kit lying around that you might want to sell me? (I allready have a bottle) all I need is the hardware.

[FordFasteRR]

naaaah.. I sold my last kit too.. but I do have 1 polished nitrous bottle with a new NOS high flow valve :)

I'm keeping that for a special day !