Opel Astra 1600 16v jerking at low rpms when car

limited info generic answer fuel delivery -weak or failing valves--coil failure--bad fuel -needs complete tune up --timing

Test fuel pressure if below spec.get new pump

Most common cause of jerking is a misfire but that would be likely to switch on the engine check light.

Certainly it would be a good idea to check if any faults had been recorded by the obd system and it would do no harm to check the spark plugs and replace if necessary and while the bonnet is open carry out a thorough visual inspection of the pipes, wires and cables and all electrical connections as a matter of good practice.

Without a more detailed description of the jerking it is difficult to make any other suggestions.

Are you sure it is not a spark issue? Some ignition modules have a low speed and a high speed section. If it is fuel, install a fuel pressure gauge you can use while driving to check if fuel pressure is really dropping at 5K rpms. If so, could be bad filter, regulator, or pump.

WHEN DID U LAST TIME SERVICE YOUR CAR?DID U REPLACE THE FUEL FILTER IF NOT REPLACE.IF THE PROBLEM IS STILL THERE CHECK FUEL PRESSURE.IF THE FUEL PRESSURE IS TOO LOW REPLACE THE FUEL PUMP.
NEXT ,CONFIRM THE VALVE TIMING AND CORRECT IF NECESSARY.IF PROBLEM STILL THERE CONDUCT COMPRESSION LOSS TEST.

how about the fuel???

try checking all the wiring pugs on the engine particuarly the ones to the crank and knock sensors if you have a managment light on then plug in a code raeder and see what codes are stored

you may need to change your fuel filter. its easily accessible under the hood. it is usually wrapped in a medal protective cover. but its easy to pop off.

diesel engine surging could have partially clogged fuel fiter, fuel injectors could be worn or dirty,fuel pump could be failing, i would replace fuel filter first have fuel injectors checked out, if you see check engine light flashing have vechicle code scan first before buying new parts.also replace air filter, diesel engine needs good volume air to work efficiently.

sounds like the iac might be giving problems, check ur idle air control valve on the side of you throttle body if its working right, replace if not.