83 300D power issues
 

I just dropped my '83 300D turbo off at the mechanic for a consultation. I took a trip to Seattle and on the way there I encountered a disturbing problem with my car.

After driving for a while (30-45 minutes) the car would start to perform weakly on even the slightest of inclines. I have had my car for about a year now, so I have some idea of what is normal and what is not. This was definitely not. The car would be cruising at 50-60mph, accelerator to the floor, and not accelerating at all. RPM's were constant at about 2500-3000.

At one point, on a long, steady incline, I could only maintain a speed of 35mph, down from 70mph when I hit the hill.

Some background information: the car has 175,000 miles on it, has a great service history, regular (read: early) oil changes, no major mechanical problems except for a replaced starter (06/01).

What should I expect the problem to be? I don't know enough about cars to check things out myself or even venture an intelligent guess. Transmission? Compression? Fuel filters? I'm worried that this is going to be the beginning of an expensive series of engine troubles.

I would love some advice ... anything you would have to say about what to look for, things to try, things to ask about, and/or when to cut my losses and sell the car for whatever I can get.

Thanks!

I would not panic yet. First, when it loses power does it smoke alot or not? Start by changing the fuel filter, next check the line to the aneoid control on the IP. If this line is plugged it limits the fuel to the IP. Check that your supply pump is working properly, check that you fuel line is not plugged. Check after you drive if your fuel tank is venting. If it will run fine for a while then start to act up you may have a venting problem. Start with the cheap and easy and work your way through. I'm sure it is not serious. Most power problems with a diesel are fuel related and usually easy to fix.

thanks!
 

thanks for the information. that sounds a lot better than what i was anticipating.

in response to your question, there is no noticeable increase in smoke output when the problem occurs.

how do i check to see that the fuel tank is venting? are these things i can check and remedy myself or should i just mention these to my mechanic (trustworthy, for the most part) and see what he finds?

thanks!

You can get an idea of what the filter looks like by taking a look at the prefilter. It should be kinda clear/opaque which lets you see if the filter element is clean or black. I'd change them anyways.

You can check the venting of the fuel tank, by pulling over and opening the fuel cap. If you hear the sound of air rushing in, the tank had created a vacuum and you have a vent problem (plugged/pinched line??).