Common Causes for Power Loss in 300D Turbo?
 

I was driving my 300D today after it has idled in the driveway while I fixed the vacuum system, and I decided I need to fix the lack of power. I'm having to floor it to get onto a 45 MPH main road in any sort of timely manner.
Some of this is probably because it's been idling in the driveway (carbon buildup?) and later I'll see if a diesel purge helps (don't think I've ever done one before).
However, it has always been pretty weak or weaker than I think it should be. What are some common methods for the loss of power? This is how it's been for quite some time, this is nothing sudden.


Also, on a side note, how do I adjust the throttle linkage? I think that part of my problem is that the first inches I push the gas pedal just get me an ever so slightly faster idle.

look the throttle linkage over real well. there is a rubber socket on the firewall which goes south after a while and creates a lot of slop in the linkage. also there are some rubber isolation parts in the linkage area just above the back of the injection pump that sortof disappear after a while too and can cause a lot of slop.

other than that plugged fuel filters come to mind.

tom w

Well, I'll hurry to get that diesel purge done and replace the fuel filters ASAP, and I'll make sure to check the linkage tomorrow (I couldn't see anything if I tried right now).

I would check your valve adjustment too. This can and will have a lot to do with power output. Valves that are tight will leak compression and cut power not to mention require service sooner!:D Such as a valve job!:eek: You might as well have your head overhauled when that happens.

Ditto, on the valve adjustment.....
 

If you have not done so, please adjust your valves.....

SB

Okay, my situation can't be explained without some background info so here goes:
I'm a high school student and this will be my ride to and from school for the next few years, and my younger brother's after that.

That said, while I don't know how to do a valve adjustment yet, my dad says he'll show me and I'm hoping to try to catch him on that this weekend (for the record, I do at least understand why you would do a valve adjustment and I have a general idea of how).

Also, I don't have any diesel purge, although my dad said he had some. He does, however, have a large supply of diesel fuel additive and some Gumout Diesel Injector Cleaner.
The injector cleaner seems as if it's supposed to be used the same way as diesel purge. Would it serve the same purpose? Would diesel purge be better in a noticeable way?
Would burning just the fuel additive yield the same effect?

Oh, and also, an update on the throttle linkage:
When I press the gas pedal, the entire linkage moves as it should, but it has no effect for the first inch or so because it turns slightly before catching a tab and moving the entire linkage. I assume it's supposed to be this way, so I guess that's fine.

Get someone to step on the go pedal with the eng off. Look under the hood at the back of the IP. There is a lever that comes up and hits a screw. However much distance there is there with the go pedal floored is how much performance you are missing. And let me tell you, the last 1/4 inch makes all the diff in the world.

Try cleaning yoru banjo bolts as well. They will hold you up if they are clogged.

Well, I did find that screw, and the throttle linkage is not hitting it when floored (http://s151.photobucket.com/albums/s138/arew264/Throttle/). How do I adjust it to fix that? Would that fix the issue where the first half inch to inch or pushing the pedal has almost no effect?

Also, pardon my noobishness here, I have pics of what I think is a banjo bolt here (http://s151.photobucket.com/albums/s138/arew264/Banjo%20Bolt/). Am I correct? I assume that to clean it I just take the bolt on top out and hose it with water, or is there something else I should use?

Also, the vacuum valve looking electrical switch behind the left side of the brake booster is the switchover valve right? My dad disconnected it (took the two vacuum lines that go to it and connected them) because it was not giving the engine enough fuel. Would cleaning it solve this problem? My understanding is that this valve protects the turbo system from overboosting, which only occurs of the wastegate sticks shut, and therefore it is not vital but would be good to have if that ever happens.

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That is one end of the line. Follow that line over to the intake manifold. The banjo bolt in the back of the intake manifold is the one you want to remove anc clean. I used break cleaner. Also like you said,make sure the entire line is clean.

With that screw that the throttle is supposed to hit, am I supposed to adjust the screw? It doesn't look to me like it would do anything but then again, I don't really know.

Don't use water!
 

Water is never used to clean engine parts. That fellow on the West Coast said he uses "break" cleaner. If he had learned to spell in Schrewl, he would have said "brake" cleaner. So, there are a number of cleaners you can use. Brake cleaner, carburetor cleaner and I find just plain old starting fluid an excellent cleaner also. Brake cleaner is generally very safe and will not catch fire.

I was saying water with the assumption that I could get it completely out. I would have dried it very thoroughly before replacing it, but I guess you're right, it's best to just avoid it altogether.

Anyway, I'm hoping to do a valve adjustment done this weekend and clean out the banjo bolt tonight.
My only remaining question is getting the throttle linkage to hit that screw as it should. Do I adjust the screw or somehow adjust the linkage? I ask because adjusting the screw wouldn't do anything that I can see... but I could definitely be wrong there.

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