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Old 05-31-2019, 02:47 AM   #8
47 dodge
Junior Member
Join Date: Mar 2019
Member Number: 9642
Posts: 10
Default Re: Holley pro jection 2d off idle stumble, poor gas mileage

Put the air fuel meter on with it own O2 sensor. It shows,
First 1/3 throttle movement very rich about 11:1
Mid range throttle 13:1
Last third 12:1

So rich across all. I disconnect the O2 sensor for the projection system, and started re tuning it to get at least close to 14.7. Then plugged the O2 sensor back in . Works much better now.

A few notes, getting the light throttle to 14.7 is not happening best there is 13. That is with the dial turned as far as it will go to the minimum. I am running it in small block mode, and did verify the throttle position sensor is set correctly.
Mid range does dial in to 14.7, however any change in throttle and it looses track and then takes a second to readjust to 14.7. Must be a rather slow processor.... Have the top end set about 13 now. So clearly only on mid range does the computer read thr O2 sensor on this system. I did not remember that from others of these I have used, but it has been some time since I have used pro jection.

Fuel mileage has improved, and the part throttle stumble has mostly gone away. Might try setting the throttle position sensor a little different to see if I can can bring light throttle in a bit closer.

Last edited by 47 dodge; 05-31-2019 at 02:51 AM.. Reason: misspelling
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