1G help with lean idle

[alexs' tsi]

so i've got a 91 talon with a 2g maf, stock injectors and ecmlink v3 to run it, as well as a 3 inch exhaust, problem is when i go to adjust the biss screw to set proper idle using dsmlink to monitor isc position, the car will run lean (about 16:1) when you drop idle to a reasonable rpm (1000) but if you set idle too high (around 1400) it'll idle much better around (15:1) afr's. I'd like to firgure out why dropping the rpm's at idle to a reasonable value will cause the car to go lean? any help is appretiated

 

[jimsgsx]

Have you checked your iac?

 

[h8r_makr]

Any exhaust leaks? That with throw off the wide band

 

[alexs' tsi]

yup i have checked it with a multimeter and it has appropriate resistances, and as a matter of fact there is an exhaust leak i have just found today where the turbo elbow meets the downpipe before my wideband sensor, would that throw it off?

 

[smills1840]

Yes that will throw it off. I had an exhaust leak in the same spot and my wideband read completely lean (22.4) at idle. As soon as I fixed the leak, it idled at 14.7 exactly like it should.

 

[tmoney20g]

Also, attach a log from cold start until rad fan comes on, then we can see more.

 

[h8r_makr]

I had a leak in the same spot and my air fuel was 15.5-16-5
I fixed it and it went back to 14-5/14-7

 

[alexs' tsi]

sweet well that could very well be my problem am gonna fix it once the car cools off, h8r i have your evil twin

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[h8r_makr]

Looks good my man!