‘85 300d Turbo Won’t Rev

[MarcusJubin]

Hello all. I was coming home from work today in high heat (99+ degrees F) and noticed my ‘85 300d get extremely sluggish. As I approached a steep slope, I could not get over 40 with my foot to the floor (the car can usually can get up this slope at 60 with ease). I lifted off the gas to stop and make a left turn. When I got back on the throttle, there was zero power. I somehow managed to make my left turn, parked the car, and walked the remaining 50 yards to my door. I checked on the car a few hours later after the temperature outside died down. There is still zero throttle response. Even in neutral, the engine will not rev. It starts up with ease, idles fine, and has run well for the past month that I have owned it. The car’s odometer got stuck at 257k after I had purchased the car. Let me know what could possibly be wrong. Hoping the transmission is not dead. Thanks

[BWhitmore]

It sounds as if you may have a fuel delivery problem. I would change all the fuel filters and also clean the screen in the fuel tank.

[Diesel911]

I agree with post #2 as the most frequent cause/s. Often when there is stuff in the Fuel Tank the you can see stuff in the plastic filter.

Change the Fuel Filters under the hood and if you still have the same issue. swap the positions of the fuel return hose (the fat cigar hose) with the fuel inlet hose where they come off of the fender well. And you need at leas 1/2 tank of fuel.

Doing the above will bypass the Fuel Tank Screen and draw fuel from a different spot on the Fuel Tank that has no screen.

Other less common possibilities are the Bell Crank (throttle support) on the Fire wall is coming apart and is keeping your linkages from moving correctly.

A plugged fuel tank vent can sometimes cause similar issues. If you remove the fuel fill cap and after a drive the problem goes away it is the tank vent is the issue.

In the picture that bell crank/throttle support is pulling out of the plastic ball that is behind the brass colored plate. Not shown but another point if failure is the rubber.