Tacoma1313

I can hear it ticking away with my stethoscope so i assume that means it is working. It sounds like a quieter injector. The thing is, it continues ticking after the engine is at op temp. Is this normal?
I thought it was supposed to shut off after the motor gets up to temp.
Thanks for any help.

scope103

The cold start injector opens ONLY during cranking. The CSI Timer a) keeps it shut off if the engine is warm, and b) shuts it off no matter what after a few seconds. But the whole shootin' match is powered from STA, so it should be off as soon as you let go of the key.

I can't begin to imagine what would cause the CSI to "tick away." It's designed to open during cranking, then close; it's not pulsed like the other injectors.

wyoming9

iTrader: (1)

Simple matter to check for voltage at the Cold start injector when there should not be.

Who can say just what might have been done in the past to try to enhance engine performance .

More fuel = more speed to some. Having the Cold start injector spraying all the time must be a good thing following this train of thought

AKHeathen

the cold start injector operates when the engine is cold. it shuts off via the "time switch" which, despite it's name, is a temp switch. if it is still operating at higher temps, then i would suspect the time switch is not working right, either being stuck on or not getting coolant to it.

Terrys87

iTrader: (1)

I wonder if you disconnected the Timing Switch, the brown one just forward of the Thermostat if it would stop its ticking.

I have never had a Cold Start Injector to fail. It has always been the Timing Switch that fails. When they failed, they would not fire the CSI. Wonder if a faulty Timing Switch could make it tick like you are mentioning?

scope103

Probably easier to just disconnect the CSI itself. If that stops the ticking, I'm not sure where I'd look. But Terrys87 has the right idea; that would point at the CSI Timer.

Tacoma1313

I disconnected the brown plug that goes into the coolant passage and now am thinking the ticking im hearing with my stethoscope on the CSI body may be resonance from elsewhere. Does the proper operation of the CSI just remain open when cold coolant is detected or does it operate like a fuel injector.

scope103

The CSI IS an injector, so yes, it operates like one. If you are asking "is it switched on an off every other revolution of the crank," the answer is no. It does not "remain" open when cold coolant is detected. For the CSI to open a) you must be cranking, b) the coolant must be "cold", and c) it only stays open a short time, NO MATTER how long you crank.

Not far from the CSI is the PAIR valve. If the screws on the cover loosen, you can hear a "buzzing" sound. You can check that out with your stethoscope, but usually just putting your finger on the vibrating cover will make the sound stop.

Does the "ticking" you hear change with engine speed?