Hi all,
I recently purchased a 1980 300 sd diesel turbo, with 230k miles on it. I had it looked over, and the mechanic said everything looked good, but on hills, I lose power. I can be traveling 55 mph, and drop down to 40 mph pretty quickly. I press on the gas, and nothing happens.

I know diesels aren't much for speed, but is this normal? Before I purchased the car, I took it for a test drive, but it wasn't hilly around where I drove.
Any tips/suggestions?
Thanks!
Liz

 

Hi - have a mechanic check your engine's compression.

 

Start with a full tune-up: air filter, fuel filters, oil change and filter, and a valve adjustment. Easy solution will be crudded up fuel/air filters or valves out of adjustment. Bad solution will be worn out engine low on compression or crudded up fuel tank.

I'm assuming this car has not been converted to run on grease.

 

When I first got my car it was deadly slow.
It turned out that my Throttle Linkage was too sloppy and because of that the Throttle arm on the fuel injection Pump was not moving as far as it was supposed to.

With the Engine Cold and not runing locate the Throttle Arm and put your hand on it to keep it from moving. Have some one step slowy on the Accelerator pedal and watcht the Linkages. If it is OK almost as soon as the Pedal is stepped on you should see the Linkage move and at the same time you should feel it trying to more the Throttle arm.

Next have your helper step all the way down on the Pedal. The Throttle Arm should go forward and rest on a Screw Stop.

If there is slop in the linkage take a look at the part that attaches to the Fire Wall. It has Rubber than can go bad and some have a Ball you cannot see behind it that is made of plastic that cracks and crumbles away.

Since I did not have a manual at the time I adjusted my Linkages I only adjusted the one closest to the Fire Wall and the one close to the Throttle Arm on the Fuel Injection Pump. That restored my car to normal. (Since not all years have the exact same linkage for mor complete adjustment you need a manual.)

Please do not forget that Plugged Fuel Filters (there is 2) and a restricted Fuel Tank Screen can also cause a similar low speed situation.

 

Thanks for the replies and suggestions, I recently took the car for a full tune-up, including air filter, fuel filter and oil change, I am pretty sure the shop didn't do a valve adjustment. The shop thinks my turbo needs to be replaced but I do also wonder about sludge in the gas tank or a plugged screen..... Diesel 9112-thanks for the heads up on throttle linkage, I'll check it out Sat morning.

*Cycleboy, nope, this is not a conversion to run on grease. I think it's best to keep the car running on regular diesel fuel.

I just got the car back today, there was better performance on the hills, and in idle, it is much smoother, but I have to drive it around a bit more.

I am also thinking of investing in a few manuals, but am starting out slow. I think it will be a nice project car.