BOOST & A Bunch of Bad ALDAs (& "disabled EGR melted that SD's engine") - Page 2 - PeachParts Mercedes-Benz Forum

veg_burner · #1 04-16-2005, 12:54 AM

Spent the entire day on this ...
The whole thing began with me noticing that my 82 was lacking in the boost department compared to the 84 that I sold which had neck snapping boost and thinking I perhaps could turn it up somehow. I scoured the archives and followed the easley procedure as well. I haven't got near the turbo yet...
I cleaned the banjo bolt fitting on the back of the intake manifold to the boost bleed valve. 10 lbs. of boost in the line. Hooked up the pressure gauge to the line going to the ALDA from the bleed valve, 0 psi, found I had a bad valve. Before I went and found myself a new valve I bypassed it and plugged straight into the ALDA, I figured I'd get my boost now but no change in performance. (Though I *did* check my 0-60 and it's at 16 secs.)
Scoured the archives again and found posts suggesting my ALDA may be bad and how to check it: pump it up to 15 lbs and see if it holds. I tested four that I found at wrecking yards and they all were no good. Stopped by a repair shop/dismantler asking for one and the guy wanted to know what I thought was wrong. He claimed that the ALDA had no function except at altitude. From what I had come to understand through all the ALDA posts I've read is the ALDA enriches the fuel according to the boost. (Also we all know adjusting it can take out the turbo lag...) He also looked under my hood and noticed the EGR lines were disconnected (haven't got around to installing the block off plate yet) and he told me it could be causing performance issues (!) He also said "You see that SD over there, we just got done re-sleeving the block and replacing two pistons. The owner of the car didn't want to spend the money replacing a faulty EGR valve so he stopped up the line with a BB. Within 6 months the engine melted. The EGR valve sends cooler (than compression chamber?) exhaust gases across the valves to help cool them down a little. If you sent fresh cold air the valves would warp."
Shows you how little even Mercedes mechanics know! He *did* go out of his way to try & help me but he sure seems to be missing something. (Another dismantler/repair shop I talked to insisted the ALDA was for adjusting the idle)
So anyway is the ALDA integral to boost or what?