I have a 2001 focus with the Z-tec (16v)engine, 132,000 miles. Occasionally when starting, if I let up on the key too soon, it will not catch, and it will not stay running at idle (it runs if i keep the revs up above 1000, no lack of power, sounds fine) after I re-start it unless I wait 10-15 minutes. what causes that?
this sounds like a cold start problem. Most likely fuel air mixture related. Possible Mass air flow sensor issue? wait for other more professional replies.
When you start the car after sitting for a while pause in the on position so the fuel pump will pressure up properly then turn to start. Just an idea.
Thanks, that is an idea. it isn’t a cold start problem, since it happens when I restart after sitting a very short time after running for a while as well.
It’s running rich. By whatever means. The basis is that the fuel cannot ignite without heat and oxygen. You have too much fuel, not enough oxygen. Which means your mixture is too rich. Have the fuel injectors tested for leaks.
the fuel is igniting. I can usually start it no problem, but occasionally it doesn’t catch. I can then start it, but have to keep the gas down when coming to a stop, even after hitting the highway for half an hour