CIS System

[Presco]

Hi all, another cis dilemma here.
I have to turn off my fuel pump in order for the car to start, then once it catches, turn the fp on.
I have heard of this b4, but cant recall if it was here.
We split the airbox apart at the seam & siliconed and rescrewed it back together so we could rule out leaky airbox. (the screws were loose so im guessing it had a blown airbox previously, but now has a pop-off valve).
Cheers in advance!

[Walt Fricke]

If the car sits overnight, there normally is zero pressure in the fuel system. Zero pressure means the cold start valve really can't squirt anything, nor can, of course, the usual fuel via the injectors flow.

For an hour or so after a running engine is turned off, there is residual pressure, so the cold start valve can inject some fuel without the fuel pump running. And that can start the engine - but it won't run for very long.

If your CIS is set up way way rich, and you try to start in the normal way, maybe the combination of cold start extra fuel and too rich a mixture won't catch?

So, like all CIS issues, testing is the way to start troubleshooting - what are the cold control pressures, and what are the warm ones. What is the air/fuel mixture when it is running? Or the CO value? Or, lacking a way to measure those two, what do the plugs look like.

Good to note the year of the engine, and stuff non-Kiwis may not know, like is this a US spec car for its year, or rest of world/euro, or maybe from Japan?

[Presco]

Oh yes theres no doubt its running rich, you can smell it and the plugs are black, black smoke out exhaust.

[Presco]

Also i checked the numbers, its a us/canada car