Runs RICH when cold! Really rich

[nofear365]

I noticed this just before I put the car in storage last spring. When I fire the car up (cold, car sitting for a few days) it starts right up but smokes my driveway out with unburned fuel. Runs fine after it warms up.

I had this issue about 5 years ago and Grady resolved it. If I remember correctly it was my cold start valve. Does this sound right?

[DMC5180]

If your CS valve was stuck ON, I would expect the engine to load up so bad it wouldn't run at all. But since I've never experienced this condition, I'm only speculating.

That said, you could have a full throttle (flap) switch that is stuck ON. Under normal conditions it enriches the fuel mixture during full throttle, but if it is stuck on during idle th engine would tend to load up some and run poorly.

Btw: Why are putting the car in storage in the spring? This is when most of us seasonal driver owners are taking it out of storage.

[nofear365]

I use my DeLorean during the fall and spring. My Jaguar XK8 comes out during the summer months because it's a convertible.

[David T]

Could be one of 2 things (or possibly both but unlikely). The Cold Start Valve is squirting in too much fuel for too long or the Control Pressure Regulator is bad. Check out both systems. The more likely cause is the CPR.
David Teitelbaum

[DMCMW Dave]

That said, you could have a full throttle (flap) switch that is stuck ON. Under normal conditions it enriches the fuel mixture during full throttle, but if it is stuck on during idle th engine would tend to load up some and run poorly.

.

It's not that much of an enrichment, and there is actually a cold-sensing switch that parallels that switch to provide the same enrichment when very cold.

[David T]

If it was the enrichment circuit (the switch or the sensor) it wouldn't "fix" itself during warm-up. Of course it can't hurt to check it, you should check all of the systems active during warm-up but the CPR and the CSV are the ones that make the biggest difference.
David Teitelbaum

[DMC5180]

It's not that much of an enrichment, and there is actually a cold-sensing switch that parallels that switch to provide the same enrichment when very cold.

I did not think it was that much enrichment either, but I have had the switch stick ON. More so I was just thinking of things that could contribute to a RICH condition.