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Main Fuel Screw and Idle Speed
#2
Driving a stage 1 tuned xud with a Bosch I can tell you that often when turning the max fuel screw the throttle arm stop screw needs to be wound out somewhat. I do refer to the stop screw on the back side of the LDA on which the throttle arm should rest when the engine is idling.

Try doing this when the engine is at normal running temp (not super hot, nor stone cold)

-Adjust the max fuel to the desired amount with the engine running and tighten its lock screw.

-Slacken the lock nut on the throttle stop screw and wound out the screw good two or three turns just to make sure it doesn't affect the idle RPM (make sure the throttle cable has enough slack for the throttle arm to 'follow' the stop screw.

-Slacken the lock nut for the hot idle on the back side of the pump. Adjust the idle to the desired RPM (tends to idle the best between 875 and 900 RPM at least in my case). Tighten the lock nut for the hot idle screw.

-Now, slowly wind in the throttle stop screw until you just hear the idle rpm's rising. Then back off the screw 1/2 to 3/4 of a turn and tighten its lock nut.

After this you should have rock solid idle and anti stall. When you rev the engine to about 3000 rpm and release the throttle abruptly the engine should within 2 to 3 seconds smoothly transition into idle, without any shaking or sounding like its gonna stall.

If you still have your problem than your bosch pump is probably knackered or worn internally.
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Messages In This Thread
Main Fuel Screw and Idle Speed - by ally406 - 03-05-2022, 05:42 PM
RE: Main Fuel Screw and Idle Speed - by johnny625 - 07-05-2022, 02:16 PM
RE: Main Fuel Screw and Idle Speed - by ally406 - 09-05-2022, 07:47 AM
RE: Main Fuel Screw and Idle Speed - by ally406 - 18-05-2022, 09:28 PM
RE: Main Fuel Screw and Idle Speed - by johnny625 - 20-05-2022, 11:42 PM
RE: Main Fuel Screw and Idle Speed - by ally406 - 26-05-2022, 10:13 AM
RE: Main Fuel Screw and Idle Speed - by Martin306 - 28-05-2022, 10:20 AM

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