Yes, thanks for reminding me about this. I saw this some years ago and I foget what Ive done about it. I seem to remember the ALDA not being very dirty, however that was a few years and many miles ago...

I agree with all above,
first thing I'd check is changing the two fuel filters.
then, I'd pull the boost hose off the alda, and verify a clear path to the Intake. soot from the EGR system will turn that oil you see on the turbo blades into a gooey paste that collects in the fittings on that system. (a good reason to disable the alda...)
also, your year vehicle has an air recirculation valve on the turbo. it could be malfunctioning, so disable it as well.
next, if you don't know how long it's been since the valves were adjusted, do them. they need adjustment every 15K, more often with some types of driving.

after these items are checked, next is the injectors, and the timing chain. actually, while the valve cover is off for the valves, you should measure chain stretch and see where you are with it.

how's your air filter?

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Both Fuel filters have been very recently changed. I just undid the banjo bolt, a little dirty but not restricted, same for the hose. So I guess thats not the culprit, (I wi**** was that simple

Where is this valve? And do you mean disabling it permanently or simply for a test? If just for a test, whats the best way to disable it?


I guess Im due for that. Its never been done since Ive owned the car (5 years now and many miles)

[QUOTE=vstech;3143023]after these items are checked, next is the injectors, and the timing chain. actually, while the valve cover is off for the valves, you should measure chain stretch and see where you are with it.

Changed only about a month ago, and it wasnt even that bad....

OK so I finally got around to step two. I obtained and hooked up a boost pressure gauge to the Alda and read it while driving. I got a reading of up to 8psi when it was revved up to the max before it switched gears.

When the needle would go down practically all the way after gear change and if there wasnt significant load being exerted. at 40 mph (probably not finnished accelerating) it would look like it averaged around 3 or 4...

The Banjo bolt pretty clean as I had indicated earlier. Does it seem like the boost pressure is about normal?

Next: Valve check and adjustment if needed? Its never been done since Ive owned it for the last 5 years, and many many miles...

Reviving this thread, as I'm deep into getting the Benz prepared for the road trip back to the MB prairies... Fully Loaded...

I don't remember if I posted about the results of the valve adjustment or not, but it was one of the single most performance improving things Ive done...

It was idling very rough before and acceleration was not so good, and that really made a difference.

I'm back on track for figuring out if my turbo is working or not.

My last post about this was getting 8psi testing off the Alda revved up max before shifting, but otherwise 4 or 5psi was the pressure. Any comments on this?

Other ongoing projects for the coming week(s):
-Subframe bushing replacement and subframe bodywork...
-vacuum system thorough checkup and diagnosis of problem.
-Another valve adjustment
-Injector cleaning, (never been done)
-Bumper repair (brackets and rubber strip solution)
-Oil and filter change
-Hit the road.

Three small things:

1 - make very sure that the lines that run from the banjo bolt on the manifold are not plugged, and are intact. I say "lines" because if it's set up as stock, the longest line should run from the banjo over to the overboost protection switch mounted on the inner firewall, then a shorter one from the switch over to the ALDA (aneroid).

When I got my current car, it was sluggish and it took me two inspections to notice that the line was split on the bottom as it exited the overboost valve.

2- not likely but possible is that overboost valve is defective. Some people just delete them. In any case, you might want to try running the line directly from the banjo bolt over into the ALDA, just to check if that makes a difference.

3- I don't think anyone mentioned it but before anything else you should, with the motor off, have someone press the accelerator pedal to the floor slowly as you watch to see if you are getting full travel on your linkages all the way to the injection pump, and that they are not rubbing or binding anywhere. I have seen people join forums saying they have paid shop charges to chase a problem like this, when all along the only problem was the linkages were messed up. (A shop gave me my old SD back with the linkages so out of whack the car would barely go 40 mph.)

__________________


Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

You should do some research on the forum here, there are lots of interesting how to's and topics covering poor performance.
Start simple, filters.
Then lines/hoses, renew the easy fuel lines if cracked or old from the steel lines in the engine compartment to the filters, feed and return, don't forget the short on post primary filter. Boost lines also.
Inspect the EGR valve, if it is stuck open lots of weird things can happen.
Look at the exhaust manifold for cracks, check that the gasket is not blown out, inspect the waste gate and the hose for it-use a mityvac to push or pull it open and note pressure or vacuum required.
Fuel tank screen-clean and inspect when your tank is empty, maybe renew the rubber hose back there
Valve adjustment, timing chain stretch, start of injection timing
Service injectors/replace shields, clean the prechambers/renew the gaskets, test compression, ream glow plugs bores.
Once all this stuff is addressed that is generally neglected and forgotten if the power is still not great time to look at injection pump calibration. This is internal to the pump, and requires removal and send out to do on a Bosch bench calibration set up. Costs around $1000, but once done you will be astounded how much power was lost (if needed). I have had this done twice to two different cars, made the car driveable again. I could not believe how much power was lost overtime. But it will only be felt if everything else is working in harmony first! This calibration made the biggest difference at lower rpms before boost came online at 2000+ rpms. I can sling gravel like crazy now, before I could barely clear an intersection safely...