In a message dated 3/20/2006 12:50:55 P.M. US Mountain Standard Time, [EMAIL PROTECTED] writes:
I'm seeing a feeling of being pushed back in the seat - smoothly and progressively as rpm's build between 2000 and 3000 rpm. Then it's a steady acceleration. But at times I don't notice the push (for lack of a better term) as the turbo spools up and the scenery starts to go by more quickly. That's my question - it seems to be more noticable at some times while other times, it just gradually adds speed - still quickly, but not with the feeling of being pressed into the seat. When I learned I didn't have an ALDA in my W123 240D, I ignored the posts when it was being discussed. I plan to read the manual to see how it works and what adjustments are suggested but if the list would provide their experiences with ALDA and what they did / how they did it -- I'd really appreciate it as the workshop manual is not always clear. Larry, The ALDA changes the injected fuel quantity as atmospheric pressure and/or boost pressure varies. Below is what I wrote in reply to previous inquiries. I think it is important enough to repeat the main theme here. I, and others on this list, believe that the injection pump calibration shifts towards leaner as the pump ages. To correct this you can spend big bucks, pull the inector pump and send it to a Bosch shop for recalibrating. OR... you can change the setting on the ALDA to compensate. This is waaaay cheaper: I firmly believe that as the fuel injection pump ages, the calibration > goes towards the lean side, due to softening of springs and wear of > various levers and fulcrums. This results in weak off-the-line > performance, especially when starting out with a cold engine. > > Jerking the FI pump and having it recalibrated could fix this problem > but it's expensive. What I believe WILL give you a kick in the pants > is adding to that shim between the ALDA/compensater, and the FI pump. > That will give you more fuel off-idle, before the boost comes in, and > the car will really step out. Especially watch the improvement when > starting out cold. > > The shim measurements are 0.705" OD, and 0.560 ID. You should be able > to duplicate the shim, in various thickness, with a Dremel and some > flat washers. > > You need a 25mm wrench (1 inch works) to turn the nut on the FI pump > clockwise while holding the ALDA with a strap wrench, big pliers, or ? > Once the nut breaks loose it is easy to turn and release the ALDA. > > Watch for shims in the base of the ALDA and/or the top of the FI pump. Use a > thin screwdriver to probe for the shims as they are virtually invisible. I > would return all existing shims or their equal, plust .040 to .060 > additional shims, to compensate for calibration shift in the FI pumps > due to age. > > There is no way of knowing how much each individual car will need-what > we are looking for is a much improved jump off idle, before the boost > comes in, and especially when the engine is cold. All this without > excess smoke at WOT on a sunny day, and no big increase in fuel > consumption > > Typically, those that break the seal on the turbo ALDAs to get to the > adjusting screw get about 1 1/2 to 1 3/4 turns CCW before they hit the > thread limit--at .025" per revolution, that would be about like a > .040" shim. I have not heard of anyone coming back CW off the max, but I have heard of > people twisting off the screw, trying to get "more"! Hence the reason for > shims-the screws can be used for fine tuning, if needed. Regards, Jim Friesen Phoenix AZ 79 300SD, 262 K miles 98 ML 320, 141 K miles
