Cold Start Switch - Where to buy?

[88AW11SC]

Hi Guys,

1988 AW11 SC

I need a new cold start switch/sender, well that's what I think its called - its the sender that grounds the cold start injector. It sits inline with the cooling system just above the trans axle, underneath the intercooler.

Anyone know where to get one for a reasonable price? I called Toyota spares - $147!!! They are not kept in Australia and needs to be ordered in.

Thanks for any help ppl!
Matt

[TooF]

id hazzard a guess tridon will have a suitable switch for you, just need to pick the size and temperature profile you want.

"TCS024 Coolant sensor 10/1987 08/1988 Coolant Sensor TCS024 replaces original green part.
TCS032 Coolant sensor 08/1988 1989 Coolant Sensor TCS032 replaces original green and grey parts."

may be the part you need,

are you sure the switch is dead ? what is your current symptom ?

[88AW11SC]

Hey Toof,

Yeah Im pretty sure the switch is dead, she cranks for a good 15-20 seconds and splutters into life when cold, when warm she fires up perfectly.

The cold start injector is definitely working still - scared the hell out of me when I grounded her out and got an atomized spray of fuel in the face.

Otherwise there is a break in the circuit somewhere but there is continuity from the cold start injector back to the switch. Didn't go further than that.

Any other ideas?

Great info, thanks mate, the TCS024 looks to be the go. I'll double check the color of the connector.

Matt.

[TooF]

before you change the sensor have you thought about rigging a wire such that you have manual control over the CSI and see if it fixes things when cold ? cold cranking problems can be a list of things.

the other thing to check would be remove the sensor and hook it up to a multimeter then put it in some water on the stove and heat it up. see what the resistance of the sensor is as it heats up. should give you an indication on whether its working properly.

[88AW11SC]

The temp rigging of a wire to fire the CSI is a great suggestion. I'll give it a run tomorrow and see what happens. Im at work all day today so it'll have to be then.

You are right, cold start switch is just a number of things that could go wrong and its not like there are moving parts in the switch to stuff up - it *should* be operational.

In regard to the cold/hot water test, am I looking for a continuity change between the pins or a resistance change? I would have guessed continuity?????

If I find the switch to be OK (after the hot water test) and we assume the wiring is OK what next? A trouble shooting plan is always a good thing...

Thanks mate, appreciate the help....

[88AW11SC]

Sorry to be a ignorant but 12v to the CSI is OK? Or does it get 5V?

Just thinking about how to wire the temp switch. Can I simply supply some power from the battery or rig a switch to ground the injector, if so which pin???

Understand I'm asking some detailed questions and dont expect you to have the answers - just hoping...

[Chrisso]

pretty sure that sensors get a +5v feed and output ranges between +5v and 0v.

[RA35GT]

Hey dood, the CSI time switch and the CSI itself gets 12V from the starter wire.

The CSI is grounded through the CSI time switch.

They both have two pins, one pin on each will be connected to a Starter +12V wire. (Work out which pin this is from your wiring, if you have a multimeter you can measure the voltage as well to be sure). (You may need some help to crank the starter and measure the voltage).

The other pin on each will be connected together. (The switch earths this wire to inject fuel from the cold start injector). To check the csi switch, check that this pin is earthed when the engine is cold and the engine is being cranked. (Its not active for very long so you need to be quick when looking).

More info here on page 20.
http://www.autoshop101.com/forms/h22.pdf

[wilbo666]

pretty sure that sensors get a +5v feed and output ranges between +5v and 0v.

BZZ.

Coldstart injector is +12V.

7M-GTE MX73 --> FTW

Cheers
Wilbo

[Chrisso]

autoshop101.com <--That's what I should have read first.

[parrot]

If you have a pickapart place near you, have a look for a late 80's EFI toyota and get one off that. As long as the plug is the same, which it will be, bobs your uncle. Worse case scenario, take the plug too. Doesn't need to be a 4AGZE

I would be very surprised if they were different.

[Cuzzo]

Hey Toof,

Yeah Im pretty sure the switch is dead, she cranks for a good 15-20 seconds and splutters into life when cold, when warm she fires up perfectly.

The cold start injector is definitely working still - scared the hell out of me when I grounded her out and got an atomized spray of fuel in the face.

Otherwise there is a break in the circuit somewhere but there is continuity from the cold start injector back to the switch. Didn't go further than that.

Any other ideas?

Great info, thanks mate, the TCS024 looks to be the go. I'll double check the color of the connector.

Matt.

Have you thought that your injectors could be leaking. Leaking fuel onto the valves and then making it harder to start? When warm they dont sit for very long therefore not leaving a heap of fuel on there. Is there a fuel smell when you finally kick it over?

[Chrisso]

If you have a pickapart place near you, have a look for a late 80's EFI toyota and get one off that. As long as the plug is the same, which it will be, bobs your uncle. Worse case scenario, take the plug too. Doesn't need to be a 4AGZE

I would be very surprised if they were different.

If you're around brissy north/west I've got a spare one sitting on the window sill in my kitchen. You're welcome to come and pick it up.

[Joshstix]

Does it actually get cold enough when you say the engine is "cold" to have the CSI come into play? I thought they were more designed for arctic type usage.

[88AW11SC]

Joshstix and cuzzo,

You guys may be onto something. I live on the Gold Coast so it wouldn't get colder than about 10 degrees C. I have no idea what temp the CSI is supposed to fire at, it wasn't firing when I had it pulled out and cranking with a cold motor. I assumed it was supposed to be....

Working on your theory cuzzo, if I manually fire the CSI, adding more fuel, she will be even harder to turn over. If she fires up quick then the CSI is supposed to fire?

I'll have a play after breaky and report back....

Thanks for the generous offer Chrisso, Im a bit far south so probably wont take you up on it but again thank you.