Backfiring, no power in 740 Turbo

My car has suddenly developed a lack of power, backfires and hard to start
I have changed the plugs and leads today , changed the distributor cap and
rotor about 12 months ago. Any suggestion would be of great help

Thanks

Damien

 

My first thought is to check the timing belt. If it has jumped the symptoms
you describe make a lot of sense.

To check it, remove the upper part of the timing belt cover. Use a socket on
the crankshaft bolt to turn the crank until the timing marks line up on TDC.
The cam sprocket at the top of the belt should line up with its timing
marks, or be 180 degrees out. If 180 out, you will want to rotate the crank
another 360 degrees clockwise to verify the timing.

The good news is that the engine you have is non-interference; timing belt
failure does not damage the engine. It also is not terribly hard to replace,
which translates to more modest labor costs to replace. If the belt has
jumped, it is not going to work at all very much longer.

Mike

 

Try unplugging the air mass meter and see if it improves.

Also if the car is '88 or earlier and has the original engine wiring
harness, replace that.

The timing belt someone else suggested is also a good thing to check,
they seldom slip, but if a tooth breaks off they could, and the symptoms
will be very similar.