cold start valve

[dwinthrup]

i got my 280z and the cold start valve it wired with a toggle switch and i was woundering if that is a good fix the reason why i ask is because when i flip the switch one way if idles at 1000rpms and when i push the gas it gets doggy but when i flip it the other way the rpms hit a bout 550 and sounds realy low but revs out fine. any thoughts

[webdawg1]

First of all if I was you. I think I'd see about getting a FSM (Factory Service Manual) for your model year. I'd also maybe see about getting the 280Z EFI Theory/Troubleshooting manual. (PDF Format so it's free) Send me your email address via PM and I'll send it to you so you can try to figure out why in the world the PO (Previous Owner) hooked it up that way??? Sounds like your idle speed is set a little low also.

webdawg1

[dwinthrup]

i have a manual for the car but it don't say much about it i was told its like a choke but i want to know is it a bad thing to be like this. and the idle wont change i tryed to change it not much luck

[sblake01]

The cold start valve puts extra fuel in the system to start the car when it's cold hence the name. It is supposed to get a signal from the thermotime switch for 8 seconds when the coolant temperature is below 35C. If it runs after that all it is doing is richening the fuel mixture and therfore making acceleration 'doggy' as you put it. I can't fathom why someone would hook it to a toggle switch. It defeats part of its function. I works in conjunction with the thermotime switch, the temperature sensor, and the air regulator to sustain a high enough idle speed to allow the car to reach operating temperature. If turning the idle screw (atop the throttle body) has no effect, you have other problems. I guess you could say the cold start system is like a choke but not the cold start valve itself. I have two cars with this system. A number of sensors are used to read the engine speed, throttle valve postition, water and air temperatures and aid flow through the intake. This info is sent to the ecu which generates the fuel injection pulse. The system is complex. I could try to explain but it would be easier for you to check out the items that webdawg1 suggested as this type of thing is tough to diagnose without actually seeing your car.

[dwinthrup]

thanx webdawg1 for the efi manual that was a go pice of info thank you much