Hi everyone,
this is my first post on this forum since the t4X4 one died. It's nice to see so many of those regulars here.

I will have lots of questions this spring, as I plan (tentatively) to swap 3.0v6 engines in my truck (I have one in a wrecked 4runner that I ran yesterday, and it has 200K km less than my truck's engine).

Today, though, I'm just looking at getting things running in my truck a bit better. Looking back at some old posts on this site, I see one guy saying that his v6 was getting terrible gas mileage in colder weather, and normal gas mileage in warmer weather. This is my problem, too.

4Crawler suggested:
1/ check cold start injector time switch
2/ check ECU coolant temperature sender

Any advice on how to check these two items? I believe I can find them both, but how to check their performance and specs? I have multimeter and some know-how...

I also wonder if it's possible to test the O2 sensor, either on or off- vehicle. I have two of them on vehicles, but both could come off for testing.
Can anyone point me to procedure/specs? Is it even possible?

Thanks very much in advance,
Scotty.

sinkut,
First - invest in / get a copy of the FSM (Factory Service Manual) - this manual would answer your questions.

The ECU coolant temp sender needs to be checked against a defined range of resistance at a specific temp.
If you want a more accurate test, you pull it off, test it in ice water, at room temp, and in boiling water.

The 02 sensor is best tested while active/hot. It will "dither" or produce a specified range of voltages, back and forth X times per specific unit time...

Again, the FSM has the specifics.

FYI there is a FSM stickied to the top of this forum.

Thank you, I have the FSM now and just need to run it through Acrobat Pro on my other machine to put all those little pages together.
Scotty

Thank you, I'll check it out and see how far I get!