boostedyota

i have been having a cold start problem jus in the cold mornings it takes forever to start, so my first idea was to test the cold start injector time switch, i took my voltmeter and put the positive on terminal STA (power) and my ground on terminal STJ (ground) on the sensor, then at 22 degrees i got 53.4 ohms, does anyone know if the sensor is good or not? or what are the specs on testing it?

boostedyota

it is 22 F

boostedyota

why are the ohms so high?, cuz it says 86f and below it should read 20-40 ohms, y is mine reading 53.4 ohms?

boostedyota

no this is the time switch its on the left it was 22 F degrees and it read 53.4 on the sensor

boostedyota

I tested the wires up to the cold start injector and I have 12 volts and I unplugged the coil and turned it over to see if the cold start injector would spray and it didnt, so I figured I had a bad cold start injector I bought a new one and put it on and it still don't start easily, it takes forever, and I am getting fuel up to the injector any ideas????

sam333

What year is your truck?
On the cold start injector, the STA terminal is the hot ( 12v) and the STJ terminal is ground.

When you turn the key to start, power goes to STA, through the cold start injector( opening it and releasing fuel) and to ground through the Cold Start Injector Time Switch. When you do this you also send power to the heater elements in the cold start switch, which limits the time the injector stays open ( only a few seconds( depends on the outside temp). On some models the ECM can overide the cold start switch and keep the injector open longer. If the engine is cold and you dont have ground from STJ through the cold start injector switch, the the switch/ wiring is bad.

When testing, the engine has to be cold enough for the switch to be closed, if you dont do it quickly the heaters will open the switch.

scope103

For what it's worth, my 1994 FSM says:
< 10C (50F) = 30-50 ohms
< 25C (77F) = 70-90 ohms
I doubt this is a difference that makes a difference, so it looks like boostedyota's cold start timer at least passes that test.

sam333

So we know the switch is closed and resistance is close enough, but does he have continuity from STJ to ground?