Contour Enthusiasts Group Archives Forums General Troubleshooting SVT barely idles - feels like running on 2 cylinders

Hi, I own an SVT which has an intermittent problem. Upon some start-ups, but not all, it barely idles. CEL on. It feels like a fuel starvation issue or as if the spark plugs were out of gap. The car only has 48k miles on it and has been maintained religiously, including injector cleaner and fuel filter replacement.
Any guesses? I checked all the vacuum hoses and they appear to be connected. The IAC valve has also been replaced. The air filter is clean.
Thanks.

Jeff (?), gotta get that code scanned. I hear Autozones will do it for free. 99.9% chance the code will lead you to the problem.

Sounds like the idle air bypass is sticking shut sometimes on cold start. Try gently tapping on it when the car is acting up. to see what it can act like when the idle air control is stuck shut you can disconnect the wiring plug on the idle air control valve on a cold start when it is acting normal and see if that makes it act the same as when it is acting up. The idle air control may be able to be cleaned (clean athe throttle body at the same time). If it is sticking and cleaning doesn't help, it will probably need to be replaced.

Just reading the codes will not help if there are no codes set. If the CEL has not been on, there are probably no codes.

It could very well be an O2 sensor as well. Had it happen on my Contour at about 29K miles. Let us know what's up when you get it scanned. Also, does it smell funny when it's running, or right after shutdown?

When I had to have my IAC replaced I never got a CEL. I don't know if I was supposed to or not, but I didn't. With the O2 sensor, I did get a CEL.

Actually, as I think about it a little more, I recommend that you start with cleaning the throttle body and idle air control. It should be done from time to time as maintenance anyway, and just might solve your problem. Do that first.

I recently replaced the IAC and cleaned the TB.

Do you think a bad O2 sensor would cause idle problems and significant lack of power?

I don't think it's a cat, since I had a pre-cat replaced recently.

Thanks for the input guys.

Test the throttle position sensor whrn the car is cold. That is what I would look at next.

Ignition coil!

Also possible.