Quote:
Originally Posted by 98E300TDman
Why is the idle rough w/out headlights? Obviously the headlights present an increased load on the engine but --jeesh -- it would seem to be a pretty small load...
 |
Does it do it when the engine is cold or hot or both?
I believe the short answer is yes, the small extra load from the alternator is enough to change the engine's speed and smooth it out...the question is why is it rough unloaded but smooth when loaded? First things first...are there any air bubbles in the clear fuel lines when the car is idling?
You may have a fouled injector that is just not popping off at idle too, but first things first...eliminate air in the lines as a possible cause first.
Next step would be to crack open the hard lines to the injectors one by one to determine which cylinder is the culpret. Just keep opening and closing them until you find the one which has no effect on the rough idle. Once you find it you can swap it out with another one and determine if it is the injector or the IP/something else which is faulty (in other words if the trouble moves with the injector it is that which is at fault...if it stays with the cylinder it could be the IP or maybe something wrong with that cylinder/valve).