cold running O2 readings

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Coops
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cold running O2 readings

Post by Coops »

what sort of readings should i be aiming for when starting from cold?


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DaveEFI
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Post by DaveEFI »

I'm not sure just how reliable an O2 sensor reading is at idle on a cold start.
I suspect not very. Mine reads about 11:1. But found the cranking pulsewidth the critical thing for a cold start.
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stevieturbo
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Re: cold running O2 readings

Post by stevieturbo »

Coops wrote:what sort of readings should i be aiming for when starting from cold?
As lean as you can that allows the engine to run nicely.

There is no correct AFR, and every setup will be different.
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sidecar
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Post by sidecar »

Here's a theory....

The AFR should be the same as when the engine is hot, the amount of fuel that you need to feed the engine will be more than when the engine is hot due to a lot of it sticking to the cold inlet track walls along with some of it returning back into a liquid form from its vapour form.

I run an Eddy 500 with no choke fitted at all, when my engine is cold the lambda probe show all the mixture circuits to be a bit leaner than when the engine is hot due to the loss of fuel burnable fuel in the inlet manifold.

Of course the above could be a load of old...
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JSF55
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Post by JSF55 »

sidecar wrote:Here's a theory....

The AFR should be the same as when the engine is hot, the amount of fuel that you need to feed the engine will be more than when the engine is hot due to a lot of it sticking to the cold inlet track walls along with some of it returning back into a liquid form from its vapour form.

I run an Eddy 500 with no choke fitted at all, when my engine is cold the lambda probe show all the mixture circuits to be a bit leaner than when the engine is hot due to the loss of fuel burnable fuel in the inlet manifold.

Of course the above could be a load of old...
Mines the same :D
So thats where it went !
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