ECT Sensor replacment question - Toyota Nation Forum : Toyota Car and Truck Forums

JetspeedCamry · 12-08-2005, 06:52 PM

I'm going to change out my ECT (Engine Coolant Temprature for the noobs

) sensor this arvo. It's the one located on that "bypass pipe" going into the manifold...there's 2 of them. I have no idea what the other is, but the one I have is definetly the ECT. I was wondering if I need to drain my coolant a bit...i think the sensor is positioned lower, so i don't want it to spew out. Anyone done this before?

Gary_602Z · 12-08-2005, 07:12 PM

My thoughts!

If it is in place you can get at quickly, disconnect the wiring for the old sensor. remove old sensor, install new. Do this when the engine is cold (no cooling system pressure). Do NOT remove radiator cap ( this will keep the coolant from running out as quickly as it wiil not be able to vent).

Gary

RedPhoenix · 12-08-2005, 09:11 PM

do a radiator flush all at the same time?

88 LE · 12-09-2005, 10:01 AM

I would drain some of the coolant.

And make sure you replace the copper crush washer too.

Mike Gerber · 12-09-2005, 10:46 AM

I agree with Gary. I would just change it quickly and like 88 LE says, be sure to use a new crush washer.

If the other plastic connector on that outlet is light brown, then that sensor is the "Cold Start Time Switch". On some of these older Camrys, Toyota used this seperate sensor to activate the cold start valve, rather than the ECT sensor. I never understood why they did it that way.

Mike

JetspeedCamry · 12-09-2005, 05:03 PM

Ok, changed it last night. I didn't drain any coolant..i was waiting for something to start coming out, but nilch. So, that was good. The sensor i got came with a crush washer, so i just used that.
As far as the color, theres two of them on the bypass pipe. The one I replaced was Green, and as it states on the wiring diagram and on sensor packaging, it's the ECT. The other one, is brown, and I have no idea what it is...perhaps its this "timing switch".
In anycase, the ECT that I replaced was SOO gone...the top plastic part could rotate freely around and was wobbly a loose. After a few twists it simply came off! So..it definetely was the time for replacement! Havn't tried the car yet, doing that later!

88 LE · 12-09-2005, 05:10 PM

The sensor with the green top is the ECT. And the one with the brown top is the start injector time switch (cold start timing switch).

From a 3S-FE:

JetspeedCamry · 12-09-2005, 05:15 PM

Ahh thanks 88! What exactly does this "time switch" do??
Can you tell me what the things are with the 2 vacuum lines coming off it??
I broke one of the ports, so i had to stick it back on!! Mines got 2 of them, totalling 4 port/4 vac lines....

88 LE · 12-09-2005, 05:38 PM

Quote:

Originally Posted by JetspeedCamry

Ahh thanks 88! What exactly does this "time switch" do??

It triggers the cold start injector based on coolant temperature. No sense in the cold start injector turning on if the engine is warm.

From my Toyota ewd manual:

Cold start injector:

2-1: 12 volts while start injector time s/w is closed and starter cranking

Start injector time s/w:

Points open above 35C (95F)
2-1: Approx. 20-40 ohms below 30C (86F)
2-1: Approx. 40-60 ohms above 40C (104F)
2-ground: Approx. 20 - 80 ohms.

So if the coolant temp is above 35C (95F) the start injector time s/w is open.

Cold start injector only works when the start injector time s/w is closed (below 35C (95F)) and the starter is cranking.

Quote:

Can you tell me what the things are with the 2 vacuum lines coming off it?? I broke one of the ports, so i had to stick it back on!! Mines got 2 of them, totalling 4 port/4 vac lines....

Their VSVs (vacuum switching valves).

Not sure what their for.

JetspeedCamry · 12-09-2005, 10:44 PM

Cool Thanks 88LE.
I might need to get those VSV's replaced, as 1 of them is holding, but the other broke, again :P...Dunno what they do! Theres nothing in the manual about it.

Anyways, the car ran perfectly. Much better cold start and the popping at idle has disappeared. So, perhaps, it was running rich..dunno. I have yet to try it out a second time after a reset, but ill do that later today.