Cold Start Valve

[CharlesBrown]

Having a cold start issue. Car will cold start but it's not very happy about it. This just started. Before, would start right up and run at fast idle 'till warm and then slow down as it should. Now, on cold start, it chokes and coughs but in a few seconds will run at the higher rpm with no further trouble. Reading in my FSM, they talk about a "cold start valve." But I've also read that the '84 Vett was the only one that has one. But they do mention it in my '88 FSM and show a picture, but I can't find it where they show it i.e., attached to the drivers side fuel rail. Question: Does the 1988 have a CSV? If so does the above sound like a problem a defective one would cause? If neither of these could be a problem would the next place to look be the Throttle position switch?

 

[muddywaters]

On my 88 there is a ninth injector for cold starting, I replaced injectors with the BoschIII's and all my starting problems went away.Check and see if fuel pressure is holding at the fuel rail.

 

[vetteoz]

: Does the 1988 have a CSV?

Cold Start Injector commonly know as the CSI on C4 Forums

Injector is in drv side of intake ( at end of steel line from end of rail )

Brass switch in intake next to CTS is cold start switch.There is a wiring harness betwen the two

 

[vetteoz]

Now, on cold start, it chokes and coughs but in a few seconds will run at the higher rpm with no further trouble

CSI is only operational when cranking cold engine (switch does not operate above a set engine temp )
It adds extra fuel like the choke on in a carb car.

If NOT working ( elec problem ) would expect longer crank time before firing
If injector leaking ( mech problem ) or on full time ( faulty switch ) , would expect rich condition all the time including while running

 

[CharlesBrown]

Thanks to you all. Sounds like this CSI is the problem and now I know where to find it.