SAiamNE

Looking to disable my cold start warm up.
Is there a write up anywhere or a simple wire to unplug?
Looking for the easiest way to disable it.

Syonyk

What are you trying to disable? The 3000 RPM for 15 seconds or so? Start it in gear.

The ~1500 RPM cold idle that gradually drops down as the engine warms up? Pain in the rear without it, leave it. If you want to remove it, bypass the coolant lines going to the throttle body and remove the idle cam from the back of the throttle body. You'll need to reset your hard idle screw as well.

-=Russ=-

My88Se

iTrader: (10)

You could always just unplug the thing, It should be on the plenum. I agree with ^ though. Its a bitch in cold weather without it.

apreludem

"The 3000 RPM for 15 seconds or so? Start it in gear."

this doesnt work for me.

HAILERS

It sounds like your NEUTRAL switch is kaput or disconnected. Put a meter on the pin at the ECU that is for the neutral switch, then go in/out of gear to see if the circuit makes/breaks.

EDIT: On a series four it's pin 1G. You should see less than a volt when in neutral and approx 12vdc when in any other gear.

Series five? Got me. They probably have plastic pins in the ECU.

EDIT: If you look at the series five FSM, the Fuel section, and the Relationship Chart, you'll see that the NEUTRAL switch has an effect on about seven functions of the engine management. How much it effects each remains to be seen.

SAiamNE

I want to disable it because around ~1500 RPMs the idle bounces up and down about 300-500 RPMs everytime..
It's annoying as hell..

It has been doing it ever since i installed a new used TPS. Does anyone know what my problem could be?

HAILERS

Oh. Not the accelerated warm up but the cold start. Cold Start works off a thing called a Thermowax, fast idle cam etc (forgot what else = etc, sort of like someone using filler words like ^know what I mean* every other breath).

It's probably a idle/timing/vacl leak issue rather than the thermowax.

Fully warm the car up and forget the bounce for now. Once warm and idling, pull the plug off the bac. If the idle is good, the car will idle at approx 750 give or take a few. If it does not idle there, then look for air leaks by spraying starter fluid on the vac hose and mating parts of the intake manifold. And don't forget to spray around the injectors (leaking grommets). Then remove the airpump feed line and spray into that hose. The idle should not change. IF it does then a function of the acv is leaking unauthorized air into the intake and the acv needs fixing.

You should put a timing light on the engine when it's fully warm and the idle is below say 900rpm. Preferably closer to 750. Adjust if required.

The up/down rpms at idle should not be attributed to the thermowax/cold start system. A download of the free fsm off the internet might help. Fuel section. Forget the rest.

HAILERS

You know a tps should be, NEEDS to be set only when the engine is fully HOT? It will output approx 1vdc to pin 2G on a series four ECU when set right (fully HOT engine of course).

SYNOYK did describe how to disable the cold start system if that's the way you want to go.

apreludem

thanks a lot hailers.