ECU temp sensor need advice

[Supraboy89]

Hey guys i have noticed when my motor is cold that it has a good bit more power than when i have been driving it for a while. I was just wondering if i unpluged the ecu temp sensor when i am racing it if it will keep my car running like the motor is still cold. or will it even make any difference. or if any thing is it bad to do this at all. The reason is because i was going to get another sensor and wire a switch to it and the one on the motor so i can switch back and forth between them when i am racing if it will even work. and yes i am going to put the other sensor in the car so it will stay cool.

 

[CPT Furious]

The ECU uses that sensor for lots of things...not just warm up. Don't bypass it. If you want more power, add more mods...

 

[Burntz]

When you drive around for awhile, underneath of your hood gets hot.. so the engine is getting hotter air and making less power.

Maybe?

 

[jdub]

^^^ HUH! :3d_frown:

If you disconnect the ECU coolant temp sensor, it will illuminate the check engine light and will maintain injector volume as if the coolant temp is 80 deg C (176 deg F - default temp). Cold, this will cause a lean idle. After warm-up the engine will run normally...you will see no gain by doing this. You will also defeat the high temp (greater than ~210 deg F) timing retard of the ECU...this helps prevent detonation.

 

[Burntz]

He said it feels like he loses power after the car warms up.. and I said its prolly because underhood gets hot, so his IC pipes get warm, air gets warm.. etc.

 

[jdub]

Well, that should have nothing to do with it...it's OAT that can have an impact. In fact, you do not want to run the car hard cold...your oil, coolant, tranny fluid, LSD, etc all need to be up at ops temp before you get on it.

 

[Supraboy89]

i am still going to use a sensor but i will have it in a cool place so it wont get hot. i heard that the car runs rich when its cold not lean. also i was going to use a switch to switch back and forth from the one on the motor to the one i have remotely placed in the car so when i race it will put more fuel in the motor

 

[jdub]

LOL...that's a getto rig if I ever saw one. Let me get this straight...you're going to have two ECU coolant sensors. Switched to fool the ECU into staying in warm-up enrichment. Have you considered the effect this will have on timing advance? Did you even know the ECU controls advance based on coolant temp? Not to mention injector volume.

You're screwing with something you have very little knowledge about. If you want to control fuel, get a MAFT Pro or SAFC. This is not the way to do it.

You asked what would happen if you disconnected the sensor...I told you...straight out of a book on the TCCS. Do what you want...I'll watch for the "My car is running like crap" thread".

 

[Supraboy89]

all i am wanting to do keep the same power when my car is cold after the car warms up . the reason i am asking these questions is because i dyno nearly 30 more hp when the motor is cold than hot. And yes i know it controls timing

 

[Poodles]

it's NOT gonna happen, you shouldn't be running the car hard until it's warmed up anyways!

way to destroy your turbo...

if you make it think it's cold, the timing won't be retarded, stock pistons don't like detonation...

 

[tekdeus]

Btw, has anyone solved their cold starting problems by replacing this sensor? If it is faulty, what is the usual default?

 

[Dunckel]

are you doing dyno runs when the engine is cold, or cool. my guess is that it is cool. sure the car will make more power after it sits for a while. i usually wait 20 minutes or so between pulls. so i guess you are confusing us. are you saying you get in your car first thing in the morning and go balls out?