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Hey guys....so I've had the car now for a couple of days and loving it. But I have noticed that it's not a smooth start up in the morning. It seems to be idling way too low for a cold start, I have to keep my foot on the throttle for like 30 seconds. Then it's fine. Isn't it supposed to have some kind of idle ramp up on cold starts then gradually come down??
 

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Three things to check. The cold start injector itself tends to gum up. It probably needs cleaned. And there is a cold start injector time switch that powers that injector for like 30 seconds or so when the coolant temperature is cold at start-up. Those sometimes fail and need replacing. And yes, even if the cold start injector is completely toast, after it stumbles to life, it should idle quite high. We have sort of the electronic version of a choke plate called an idle air control valve which is a little stepper motor that opens and closes a bypass. A relay is supposed to close it down, like a choke, when you shut off the car in preparation for the next mornings cold start. If you listen close, you can hear some clicking after you shut off the engine, or you should be able to hear clicking as the stepper motor steps down like 256 times. There's threads on here with instructions how to check, clean, test them all. But its all just typical stuff for the age of the car.
 
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Ok then.... sounds like work.
Are these parts easy to access and readily available? Do you know much do they typically cost? Thanks
 

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They are 34 to 38 years old. I started losing my hair at 21 and its been all downhill since. My Supra is holding up better than I am. ;)
 

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from the problem description given, it sounds like the cold start time switch on the thermostat housing/neck.

Although the cold start injector could cause this if not operating nominally, in the several cars I've owned, the fault was the cold start injector time switch. Measure its resistance per the TSRM using the link others provided. If you can't or do not know how to do that, I would suggest to remove the connector from the time switch and put a paper clip in the connector. Then start the car and if the time switch is the ONLY issue, the car will start up after a crank or two. Only do this once or twice as you are actually shorting the circuit, and don't think you can just leave a jumper in the connector and be done with it.

NOTE: don't just try to pull the connector off the switch or it will break. There is a silver wire that loops around the plastic connector that has to be pulled away from the connector to release it from the switch. If you are not familiar with your supra yet, you will find many electrical connectors are held in place with this type of wire. I use a dental pick to pull the two sides of the securing wire away from the connector... sometime you only need to pull one side and the connector can then be pulled off.

Rick
 

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IF you break a connector or both, pigtails can be had at a NAPA on line store. Mine were corroded and not making good contact. One is the time switch and the other one tell the ECU what the coolant temperature really is. See the TSRM to
check them both. The one on the right can and will affect your fuel mileage numbers!


 
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