1987gt40ttop

i have a turbo set up that i recently made the switch from draw through to blow through. the meter is calibrated for the injectors and all and ive even had it dyno tuned. i have had this irratic idle that is almost like a surge from a vacuum leak that i havent been able to sort out. on the dyno we got it close but not perfect, but we figured the meter was to far away(in fender) and to close to a bend so we let it go and went on with the tune. ive now moved it to about 6'' away from the throttle body and in as straight pipe as possible and i still have the issue. i did switch throttle bodies at the same time from 65mm to 75mm but i set the tps to the speced .90 ohms. at this point im not sure wat else to try, the meter is the 05 style with the adapter same size as intercooler pipe with no reducers or anything.

holyshift

Try clocking the meter in different positions?

1987gt40ttop

yea i tried clocking it with no real change. i turned the idle up to about 1100-1200 rpm and it smoothed right out. the problem i was having was when it would come off fast idle from initial start or after coming off a load the idle would drop real low and surge up and down. i know some guys with bigger throttle bodies drill holes in the throttle plate to get more air through just at idle, which it seems to be my problem since the higher idle smoothed it out, but have you ever heard anything like that?