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This morning it was sorta chilly...well about 45 degrees(hey thats cold here in La.)and I had to crank my '78 280Z...19 times (I counted) before it started. I assume this is a problem with cold start valve...but can someone tell me how to check it and\or fix ? Does anyone else have this much trouble? Runs fine once you get it going
 

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Simple system. Thermotime switch controls whether the CSV opens or not. If cold enough, it allows voltage during cranking to be applied to the CSV. When ignition is released from START, the voltage stops. So, two conditions have to be met. Cold enough that the Thermotime switch is closed, and key in the START position.

Some probabilities/possibilities:

CSV malfunctioning, will not open. (unlikely, but possible)
No fuel in fuel rail, CSV opens but not spraying fuel.
Thermotime switch bad, not applying voltage.
Wiring b/t Thermotime and CSV is bad or corroded.
Wiring b/t Thermotime and FI relay is bad.
FI relay is bad.

Some of this is easy to check.

The easiest thing to do is first pull off the connector of the thermotime switch, and check the contacts of the switch when the engine is cold. Switch is located in the thermostat housing, and should be the one directly under the one wire temp sender unit (so, the lower passenger side switch). As long as the temperature of the engine water is below the range of 57 to 71 F the switch should be closed. Be warned that if you leave the key to on, the switch will open. There is a heater built in to the switch to keep the CSV from continuing to dump fuel in after it starts and runs. An open on a cold morning would indicate a faulty switch.

Leaving connector off of the Thermotime switch, jumper the switch connector with a paper clip or something suitable. Make sure it doesn't contact any grounds. There should be voltage present. Take off the two bolts holding your CSV to the intake. Get a glass jar, and stuff the whole valve in there. Get in the car and crank on it. You should see fuel spray into the jar. If you do, disconnect the jumper, and plug the connector back in. Crank again. You should see fuel again. If not, the switch is bad. If you didn't see it the first time, try tracking down your wiring, back to the FI relay. Use your FSM. It will tell you exactly what to look for.

That should get you started. Let us know how it goes.
 
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