Ive noticed power issues for the last year or more. I know my 85 300TD wagon should be able to climb an average hill and not decelerate. Thats not the case but Ive not had the time and perhaps Ive been loathing where to even start to look for the problem.

I noticed recently that I havent been hearing the Turbo whine like it used to. Does anyone have any first action steps to help diagnose the problem?

Thanks
Michael

Firstly you want to remove the turbo inlet pipe and confirm that you can spin it by hand without any noticable binding. After that I'd "T" in a boost gauge to the line going to the aneroid and observe what its doing when you put a load on the engine.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

Sounds like a good start. Will a Mityvac do the job for the boost gauge? or is it the opposite air flow Ill be testing...

Thanks

I don't have a Mightyvac made Mightyvac (I have an Actron hand Held Vacuum Tester) but mine only has Vacuum on it; no pressure.

What you need is something that has a pressure Gauge that goes up to 12 psi

I think a gasser Fuel Injection type Pressure Gauge might go up that High.

Call Autozone or someplace similar and see if they have a Free Rental one available.

If it runs better when the Fuel Tank is filled I would suspect some sort of Fuel Supply issue like Filter being restricted, Fuel Tank screen being restricted.
Could also be the Fuel Supply Pump or Fuel Pressure Relief/Overflow Valve issue.

__________________
84 300D, 82 Volvo 244Gl Diesel

Where I live theres no free lending at car part stores. They give you a weird look if you ask anything like that...

Has anyone tried a precise tire gauge or bicycle pump with built in gauge?

Can anyone point out to me what the boost pressure aneroid looks like? Im not sure where I should be making the test.

I was able to spin the turbine in the turbo easily it seemed to me. (is there only the one turbine to check? I checked it by removing the air cleaner and the large plastic "hose" that connects to it and to the Turbo.

Its was a bit oily, not sure if thats normal.

PVC valve can make it oily. As long as it spins aand the blades do not touch the housing, it is in good enough shape to start testing elsewhere.

thank you. And the aneroid? Any hints or photos to where it is?

Thanks again
Michael

Don't know how your car is set up. Injection pump should have an aluminum diaphram type device on top - probably with a plastic plug in the center top. This is called the "ALDA" Vacuum line going to it should have boost presuure in it under load. Just tee off that line to some sort of presure gauge that will read 10-15 lbs. Position gauge so you can see it while driving and put your foot in it! should show positive presure pretty quickly. The line to the ALDA usually comes from the intake manifold and they are known to fill up with soot. No boost presure to the ALDA means no fuel enrichment under load and reduced power. Another place that causes trouble is the fuel filters. Should be changed at least every 1000 gallons or sooner. Cjange both if they have not been done in awhile.

Great thanks. I did just change the fuel filter. So that shouldnt be the culprit.

Would the reading still be effective revving the engine in Neutral?

No the turbo needs load to make boost, drive it dont just free rev it.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

The Aneroid is a Generic term for the ALDA on the Fuel Injection Pump.

Trace that Boost Pressure Tubing from the rear of the Intake Maifold acrossed to the Overpressure Realy Switch and then from there on to the ALDA.

You can actually check the Boost Pressure by tapping into any place along the Boost Pressure Line but it is possible for that Line and the Over Pressure Relay Switch to be plugged.

By connecting the Boost Pressure Gauged near the ALDA you get to see how Much Pressure actually makes it there.

I wrot ADLA over the ADLA in the Pic. In My case the Orange Hose connects the ADLA because I replaced the original Plastic Tubing with a Silicon Vacuum Hose.

Attached Thumbnails

 

__________________
84 300D, 82 Volvo 244Gl Diesel

A quick test is to remove the ALDA period but it is not a healthy engine choice.

Cheers, Mike

There are many other things that can cause your symptoms. Valve adjustment comes to mind first. Throttle linkage also. Filters of course. Primary filter, secondary, and tank strainer. .and the air filter.
Air in the fuel lines can cause a lack of power too.

__________________
I could not own any MB without the help from you...fellow forum members.


83 300td 207,XXX

Ohhh yeah, check this out. I think it might be right up your alley....and easy to checkMercedes ALDA boost system service

This might get you back to 100% withoutout spending a nickel.

__________________
I could not own any MB without the help from you...fellow forum members.


83 300td 207,XXX