Simplifying engine harness

[Bax]

I've stripped my engine harness and I'm in the process of building a new one. I have also remove some stuff that I don't need (both prc solenoids, purge control solenoid and charcoal canister , isc valve , water thermosensor).
In the manual it doesn't state any consequences as a result of all of these missing.
Do you think I must keep any of these for correct engine behaviour?
I also have emanage blue to fine tune if necessary.
So far I've kept:
Vaf
tps
knock sensor
oxygen sensor
clutch switch

[almighty4wd]

the car uses the water thermo to know when to turn the radiator fan on and off, and when to lower the idle. the ISC is needed for idle control as well.

The purge keeps the tank in a neutral air pressure state by venting gases into the motor. Helps if you don't like the smell of gas floating around. The charcoal can is just part of this.

The clutch switch on the tranny? pointless. You drive a manual, not an auto.

I'm going to assume you're setting this up for racing ONLY because what you've ditched doesn't make it driveable anywhere but on a track. Unless you like no control over your idle. There is very little you can strip from the engine sensors and still maintain a good functioning engine.

[matt_fulghum]

You can actually live without an idle vale fairly well... but it'll idle around 1000 rpm or so. It'd be best to keep it, and it's only a couple extra wires.

You REALLY wanna keep the charcoal canister. It vents the gas tank, as almighty4wd pointed out. Not only does this likely protect you from exploding into flames, but it also chops gasoline vapor emissions from your car by about 90%. It weighs very little, so if you don't keep it in there you're an asshole

Not to mention you'll really notice that it's missing.

I can't remember whether you should leave the vacuum port on it open or route it to a vacuum port on the engine. It does affect cold drivability a bit, but not THAT much. I just left everything in there and run it when the FSM said to.

[therieldeal]

i have no idle control, and my car idles at about 1200-1500 depending on the situation, with the adjustment screw cranked all the way in. i'm thinking about plugging the inlet of the IAC and adjusting with just the screw... just to see if i can get it to go a little lower. either that or actually getting the idle control working.. haha.

i left my charcoal canister in, with the vent open.. nothing connected to the motor. seems fine.. no odors or anything

oh yeah and you definately need the coolant temp sensors... both of them. one is used to adjust the air/fuel mixture based on temperature... good luck starting in cold weather without it. the other turns the fan on and off directly (well, through a relay).

[matt_fulghum]

I think he meant the thermoswitch for the fan.

... I *hope* he meant the thermoswitch for the fan

[Bax]

The thermoswitch (the one on the thermostat ) of course is there.
I mean ditching the water thermosensor (the green 2 wire one). I had it already off for a year.by having it unplugged the ecu thinks that the coolant is cold (20C) so no problem with starting in cold weather.
I'll see what I will do.
I decided to move the diagnostic port and the fuel pump relay inside the car. Less cables running through the engine means less trouble and better looks.

[therieldeal]

yeah and when the ecu thinks the coolant is cold, it makes the car run stupid rich... wasting gas and wasting power.

[Bax]

Which I can Tune with the emanage and my wideband

[therieldeal]

no, no you cant. because then it wont run rich enough to stay running when the engine is cold. you need that sensor.

[Bax]

ok. I'll see what I can do. I lived without it 1 year now. Didn't have any probs..

[therieldeal]

thast because its always running rich. so when its cold... its rich enough to stay running. and when its warm... its just, well, really rich. an engine can run at very rich AFR's but if it gets too lean it will not run.

pull up the megasquirt site real quick and read about warmup enrichment

[GrEg]

I just hope you die and you let me have that sweet bpt....