1983 300sd no power

[AdrianMiura]

Forgive me if this has been already covered in other posts (Although I have been searching.)
I’m new to diesels and have been learning a lot from the is forum. I just picked up a 1983 sd and am a little concerned with its lack of power. It has approximately 190k. So from reading posts I did the valves. Most of the intake valves were ok but all of the exhaust valves needed adjusting (there was no clearance). I also did the diesel purge, and changed the fuel filers.
I’m thinking maybe it’s the turbo (On the front of the compressor it is labeled AiRearch T3 ( Garret TA 0301))
)?
I hooked a vacuum gage (it’s a combo gage with psi) to the delivery line from the intake manifold (I disconnected this line form the “switch over valve” that goes to the aneroid compensator) and at 3000 rpm I’m only getting 2.5-3psi of pressure. Maybe the boost pressure control valve/waste gate? Is there a test procedure for this?
Thanks
Adrian

[coonerboy]

If your testing boost in the driveway just reving the engine, then those may be the numbers I would expect. To accurately test boost the car needs to be under some sort of load(accelerating)

Check the ALDA line from the intake manifold to the over boost switch on the firewall.

Here is a good link http://www.dieselgiant.com/mercedesaldaboostsystemservi.htm

[AdrianMiura]

Thanks
did the ALDA system service as stated in your reply. and will do a compression test in the morning.
Any other test i should perform?

Adrian

[Cr from Texas]

It may be as simple as worn out throttle linkages from the accelerator pedal to the IP not giving full range of movement to the IP. Mine was.

[AdrianMiura]

Thanks for the info checked the linkage and it is fine.
Did the compression test. When testing I removed all injectors prior to running test. Not sure if this is how it is done on a diesel.
1 =280
2=300
3=300
4=320
5=280
Is this low? The motor starts fine cold and doesn’t seem to smoke?
I read that you should replace the injector heat shield when reinstalling the injector is this true? If so how do you remove them?
Thanks
Adrian

[coonerboy]

Those numbers look ok. Can you try running the car on an isolated fuel source. By this I mean, disconnect the fuel lines near the firewall and stick them into a container of diesel, something like is done in a diesel purge. Then run the car and see if its any better. If it does get better then you know you have a fuel restriction, likely a tank screen.

[BoostJunkie]

When you did the ALDA service, did you just clean the bolts and the lines? I had loss of power too. I cleaned the lines and bolts out with no better results. When I pulled the switchover valve off of the firewall I found that it to had become blocked. A little carb cleaner and re-installed and I had power again.

Oh, and post the boost you are getting under load, if you will.

[Maxbumpo]

Injector heat shields are one-time use, so you need to get new ones. The old ones should be in the bottom of the injector hole, usually they will come out easily with a magnet but sometimes they are really stuck. In those instances, you need to get creative to find a way to get them out. I made a small hook with a cheap screwdriver and it was still a wrestling match to convince one particular heat shield to come free.

[AdrianMiura]

I have new shields on order and will replace once they arrive.
However is there a problem with keeping the old ones in a using the vehicle? If it will lead to damage I will hold off on running the vehicle.

[Maxbumpo]

It can lead to damage - they are there for a reason! Won't happen immediately, so you can start the car to move it around, but I wouldn't use the car for more than that or you risk doing damage to the injectors.

[AdrianMiura]

Thanks for all the advice
I think I have done all I can with adjustments and cleaning.