'87 240 DL 240 000km --2 problems

1) Sudden loss of power. Have viewed many other posts including
www.brickboard.com but my problem seems to be unique. While driving, when
the engine reaches 2000 RPM suddenly drops to 1000 and will stay there
regardless of pressure on accelerator pedal, until I shift up, then happens
again. If I let off the accelerator pedal quickly it will sometimes give a
tiny backfire. When I start the engine and it idles a little low the chances
of this happening is smaller, when it idles perfectly the greater the
chances. New plugs & wires, tried 3 or 4 used mass air flows, cleaned
throttle body & flametrap, no holes in air tube between MAF and throttle
body, O2 sensor good, cat conv hollowed out.

2) In cold weather the rear end makes loud steady noise. The only way to
describe it is that it sounds like 2 balloons rubbing together. Sometimes
sounds like it is coming from differential sometimes from rear wheel area.
But only in cold weather!!!!!

 

Sounds like you have a fuel, air , or exhaust restriction.
Richard W.

 

Have you checked your computer for trouble codes?

 

The wiring harness is probably at fault. The insulation cracks where it goes
under the intake manifold. Split the sheath on the harness and inspect the
wires.