Adjusting screws

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T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Adjusting screws

Post by T.Hanson »

One large screw on the throttle body, one under the AFM.

I understand ( timed correctly first ) set throttle body screw to idle @ 850.

Swapped in different AFM and in tank pump. Ended pump buzzing, maybe some improvement in throttle springiness, sensitivity. It still feels like it's starving for fuel on acceleration, or if it were a Kart engine I'd richen up the low end.

Can the screw under the AFM be turned out, counter clockwise, to give it more fuel for better throttle response ?

What else ? New O2 sensor coming, cat probably ain't great. Far as I know all the ignition parts are good,...vacuum leak ?

Weird the gas pedal is so springy, jerky compared to '79.
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Post by T.Hanson »

Set idle to 1000. For what it's worth, no stumble or hesitation with hard pedal push down as before.

Maybe I'm nuts. Is your (anybody) throttle very hooked up, snappy, direct ? I mean, let off, it slows down, NOW. Not coasty smooth. And If I pump the gas pedal the engine bounces, boing, boing working on the guibo.

I can drive it smoothly by applying the throttle smoothly, but this car, so far, is much more race car feel than my '79.
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Mike W.
Posts: 2889
Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Post by Mike W. »

Can the screw under the AFM be turned out, counter clockwise, to give it more fuel for better throttle response ?
No, it works the other way. It's an air bypass, not a fuel adjustment, and turning the screw out leans it out, excepting that the O2 sensor should override it if everything is working as it should.
Mike W.



02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
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