83 300D power surge issue still happening!
 

I have been trying to fix this issue for a month now. When driving the car the power will go up and down with no pattern to it. Up hill, downhill, turning, straight, UGH! It will start to accelerate properly then it will be a dog, but sometimes it works the way it should. Then all of the sudden back to being a dog. When it's running properly it runs great. I don't get it! I'm pulling my hair out!

Items I've addressed to try and fix this issue:
-Fuel tank removed, cleaned and new tank screen.
-New fuel filters
-New injectors
-Check vent line for blockage
-Blocked off EGR
-Checked tranny fluid
-Valve adjustment (double checked it)
-Cleaned the banjo bolt


I've been through a few tanks of diesel from different places, still does it. Could the wastegate be an issue? I have a used one sitting around I could swap. What other things can it be!

Thanks in advance

Put a pressure gauge on the manifold, that will tell you if there is a variation in turbo operation.

Where is the best place to tap in?

Line from manifold to overboost protection switch is usually easy to tap into.

Sounds a lot like a problem with the manifold pressure signal getting to the ALDA, or maybe the ALDA failing in a strange way (but I've never heard of one failing to cause a condition like yours).

I think you guys are onto something because I unplugged the wire going to the pressure switch on the manifold (see picture) and it stopped doing it.

So I'm wondering if it's the switch or the switch over valve? If I unplugged the pressure switch wouldn't that take out the whole overboost protection system?

Thanks guys, we are realllllllll close!!!!!

Your waste gate hose is hosed. $2 5 minute fix.

I'll replace tomorrow! How does the wastegate hose effect the intake pressure switch?