Lumpy tick over problem
 

Hi.. I recently replaced a blown headgasket on my low mileage (56k) 1.8 k series 2004.. It drives very smoothly but when stationary you can feel a slight shake to the car.
I'm sure the tick over was quite smooth before. I cleaned the Maf sensor and checked the throttle body was clean but can't see anywhere to adjust the mixture. I have not replaced the plugs.. So that is my next move but wondered if there were any thoughts as to anything else to try.. Did try increasing the tick over speed but it always sat just below 1000 rpm so probably 800.. To be honest the adjustment doesn't make much difference to the speed.. It seems to settle at about the 800 revs unless I really use 2 + turns of the screw when it will rev too high.. Any thoughts

Gap the plugs to .75mm, might help, also, reset the iacv by turning the ignition on, press the accelerator pedal 5 times quickly, ignition back off, then restart the car.

Hi Mike,

You can't adjust the idle speed or "mixture"; they're set by the ECM.
I would begin by checking the spark plug gaps. The spec. is 1.0 mm but some owners reduce it as mentioned above.

Simon :}

After the adjustments suggested, take the car for a twenty mile, mixed driving run so the control system relearns/optimises everything.


TC

Many thanks to Suzublu, SD1too, and T-Cut for your advice and recomends.. Carried out all that and the engine feels brighter but the tick over, although a bit better still makes the engine shake a little. I think the brightness of the engine is down to the plug setting at 0.75 but it's just that I'm sure before the work it was hard to detect the engine was even on at tick over. I'm a bit stuck as to what to do next. I'm even doubting the cambelt perhaps being one groove out on one of the cams but it runs smooth and has plenty of pull. Any further thoughts would be much appreciated. Happy to travel from St Albans to any garage that might be recommended. Really appreciate all your help to date.

Try a new set of plugs leads to eliminate them. They can break internally and on the plug caps.

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