FI cold start Options

[cal44]

The car, 1974, retains its original FI. Fires up no problem, but, until it warms up it almost dies as the rpm is almost zero, or, it almost dies until the temp bumps up.
When warm it is a nice 800/900 rpms and idles nicely.

I tried to do a search but it never works for me as the website is beyond my mortal understanding.

Best

[McMark]

The cold start valve on a stock D-Jet FI ONLY operates when two conditions are true.

1) When the temp is below XX degrees. The thermo-time switch below plenum handles this, not the ECU, not the head temp sensor, not the air temp sensor.

---AND---

2) When the starter is cranking. Ones the engine fires and you let go of they key, the CSV turns off.


To put it a different way, the CVS has two wires -- power and ground. Power is supplied through the yellow starter wire. If the starter is turning the CSV has power. If the starter is not turning, the CSV has no power supply. Ground for the CSV is through the Thero-time switch. This is a simple temp controlled switch. If the thermo-time switch is below XX degrees then the CSV has a ground connection. If the temp is above XX then there is no ground and the CSV can't spray.

It's a pretty smart system that simply evaluates two conditions, BOTH of which must be true in order for the CSV is open and spray fuel. Most people consider it a fuel injection component, but to my way of thinking, it's a completely independant, stand-alone system. You could remove the ECU completely, and the CSV system will still operate.