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Main Fuel Screw and Idle Speed
I have an odd problem on my 406 with Bosch and TD04. Car is running great and I'm now trying to dial in some more fuel. I'm using the idle adjustment at the back of the pump to bring the idle speed back down after turning the fuelling up (I usually go with 1,000rpm since that's decent with cold veggie). However, often when I start it, or dip the clutch at a junction, it will start to chug at 500rpm. A blip of the throttle and it will usually come back to normal idle speed. This will persist until I return the fuelling and idle adjustments back to standard, so I'm in the position of not being able to add more fuel  Confused Only other adjustment is a ground LDA, otherwise it's an unmolested pump. Anyone seen this before?
'95 Peugeot 405 GLX with XU10J4RS and ITB's
'97 Peugeot 406 1.9TD with TD04
'05 RenaultSport 182 Cup
Thanks given by:
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.
Thanks given by:
That's some great info Johnny thanks! I'll hopefully get back to it this week and try your suggestions. It's also crying out for a gov mod.
'95 Peugeot 405 GLX with XU10J4RS and ITB's
'97 Peugeot 406 1.9TD with TD04
'05 RenaultSport 182 Cup
Thanks given by:

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