No, it dosent have a Holley 4 barrel...

The screw on top of the IP that functions to richen/lean the mix... does it tune like a power valve.i.e, meaning does it directly effect part throttle mix/acceleration?

The car has a part throttle bog, which is accompanied by nailing and puffs out the tailpipe. I'm thinking its going too rich.

If I wanted to experiment ( which is how I became exceptional at tuning Holley 4 bbls), and lean it out a bit, I would turn the screw CW correct?

I have a feeling someone tweaked it before. Never assume, right.

Actually , my first question is most relevant, this is some sort of enrichment circuit governor that effects part throttle fuel flow?

And thnx for ur patience on teh noob questions; I do run searches before I ask for ur time.

The part you are looking at is called the ALDA and in short, it is an aneroid compensator that alters fuel delivery based on boost pressure. Tweaking the ALDA can improve off-idle performance and a plugged pressure line from the manifold to the ALDA can affect overall performance. Do a search in here on "ALDA"...plenty of stuff already written about it.

BTW: Diesels don't adjust mixture, they change power settings by altering the amount of fuel delivered to the combustion chamber after it is charged with air.

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Never a dull moment at Berry Hill Farm.

Sir, I love your bouncing avatar. Love it love it love it. Tasty, yet tastefully done!

Uh, I did'nt think this n/a mill had an ALDA? Why my searches weren't producing fruit I suppose. Was looking for a mechanical adjustment for these "power settings" you refer to.

What year is your car? I am not sure about the 1995's, but I know the 1996 and 97 uses electronic rack modulation, and I personally would not start turning screws on the injection pump unless I wanted a good reason to have to take it to a diesel shop.

There is no rich/lean adjustment on the pump that can be adjusted externally.

I would start by having the injectors pop-tested.

My mistake. Didn't realize that your's was N/A.

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Never a dull moment at Berry Hill Farm.

INjs all rebuilt. Trying to learn more about the various components of the engine. THNX!

I would leave that IP alone unless there was something drastically wrong. The OM606's are pretty much maintainence free when it come to adjusting things of that nature. No valve adjustment's needed etc....

Those things are expensive to repair/replace... Just my $0.02

Perhaps the intake resonance flaps are sticking, resulting in the engine being starved of air when the pedal is pressed. Because there IS no ALDA to adjust amount of fuel based on charge air/amount of air, too much fuel is injected for the low amount of air being allowed in through the stuck flaps. Just my 2¢.

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99 E300 TD -- sold
01 540i 6 spd

Resonace flaps were causing some surging at a steady rpm. They were cleaned, as was the intake when I had the injectors out. The system is now disabled until I sort it out. It must be the transducer ( the electro/vaccum box). Also shut down the EGR.

Yeah, its either bad chamber/bad ring seal, or an outside chance ( way outside according to the guy who rebuild the injs) that the IP has one cyl out of time.

And then there was that two pin connecttor which was part of the new pre glow harness which had no place to go! I dont like enigmas.

THNX for the assist folks, the enigma continues.

I assume it IS possible to have one bad GP w/o the GP light coming on ( sometiems it will come on for a few seconds, flicker and go off), and with the GPs all testing at .4 ohm ( batttery was low in the VOM).

GP I dont look forward to, its called pulling the head on the 606.


The only air/fuel mix is that ALDA "hat" and the air valve just upstream from the filter. Linkages seem to be mechanically/geometrically OK, IP goes "WOT" and all.

For now, I'm forgoing any more Italian tuneups (the tranny bears the brunt of that abuse) and driving the car with a light foot so as not to cause the acceleration rattles and related smoke.

Biopower, how about a "cartridge style" GP for these twin cam heads that's easy changed out. ?