Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Marrs on April 05, 2012, 20:25:12

Title: FI Pump Screw "click"
Post by: Marrs on April 05, 2012, 20:25:12

I'm trying to adjust my idle at "park" since it has the familiar hunting between 700-1,000 rpm when warm and at idle. I tried turning the adjustment screw on the back (the one with the spring beneath it) but heard no clicking so returned it to where it was. I marked it and turned it one full turn to be sure you didn't have to go quite a ways to get it to click, so returned it to where it was again, and then turned it 1/4 turn clockwise to see if that helps. Can anyone tell me approximately how many "clicks" per full turn of the screw?

Title: Re: My FI pump screw does not "click", how many clicks equal one full turn?
Post by: Marrs on April 05, 2012, 20:34:58

Nevermind, I was being too paranoid to push it in too far to properly engage, but once I did I got it to click. Starting off with 3-clicks to see how it does, will adjust incrementally from there.

Title: Re: FI Pump Screw "click"
Post by: ja17 on April 06, 2012, 03:43:00

Hello Marrs,
Six clicks on a full turn.

Title: Re: FI Pump Screw "click"
Post by: Marrs on April 06, 2012, 04:26:30

Thank you for the info. Also, if it helps others down the road (literally and figuratively) by advancing clockwise 3-clicks it ran poorly, so I did another 3-clicks clockwise and it was even worse, returned to original position (-6 clicks to return) and then continued by turning 3-clicks counter-clockwise to lean the mixture a bit. It was counter-intuitive as I assumed I would need to add fuel to the mix, yet there it is, so don't always assume you need more fuel if you have a low idle.

Title: Re: FI Pump Screw "click"
Post by: glenn on April 07, 2012, 00:44:39

Marrs,  Welcome to FIP/warm idle/fuel management, MB style.  With the engine warmed up to operating temp, 1)idle at 750 rpm (with 50 rpm of rich), 2)WRD air shut off, 3)WRD heat element has extended to move the FIP WRD/barometer lever to max(no fuel enrichment), 4)CSV closed, 5)venturi butterfly closed.  This means the FIP is pumping just enough gas to run the engine at 800 rpm with optimum idle air at elevation.   Closing the idle air screw will decrease rpm(close idle air a little to get 750 rpm).  Opening the idle air screw will increase rpm to 800 then further opening will decrease rpm.
ah ha,  FIP nirvana!