Quote:
Originally Posted by jd4614
The guy that owned my 300SD (83) decided his ALDA wasn't right so he removed the crossover canister on the firewall and routed the pressure line from the manifold directly to the ALDA. The car is sluggish and I can't feel turbo boost at all, but I do see smoke at full throttle. Any ideas what having manifold pressure going directly to the ALDA will do?
I suspect the vacuum is a bit wierd too as the transmission shifts very hard (especially into 4th gear at any throttle position). Any chance they are related?
Any thoughts would be appreciated.
Joe
83 300SD
82 Bluebird Wanderlodge FC33 (3208NA Cat)
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I've run directly from the manifold to the ALDA for years with no problem, but I finally nabbed a switchover valve from a wrecked car and installed it back like the factory intended it, to protect the engine if the Boost gets too high. If the switch gets activated it reduces fuel to the injectors to prevent possible damage to the headgasket, etc from excessive boost (over about 14.5 psi).
Proper Vacuum is necessary for proper transmision shifting. Harsh shifts are an indication that vacuum levels is too low (meaning not there).
On the rear of the Inj Pump is a vacuum modulator valve, its plastic and has some vac lines running to and from it. These valves can get leaky internally, the best thing is to replace it if your vacuum is proper at the vac pump but shifts are getting harsh. Check to see the vac lines are all in place and verify that you don't have a vac leak somewhere. Are the door locks operating OK? If not then you may want to temporarily plug the line that supplies vac to the locking system (at the firewall) to see if that is involved. Welcome to the world of vacuum stuff as it relates to the Mercedes. Troubleshooting this can be a challenge if you don't have a vac gauge and a Mity Vac (hand pump) on hand.
Also, has your ALDA been un-capped? A picture of it would help us see if soemone has cracked the seal thereby allowing the adjustment nut to be adjusted, that can, if overdone, make the engine belch some pretty black smoke.