Car

Ask a Car Question, Get an Answer ASAP!

Have your own Car question?

29 Auto Mechanics are Online Now

characters left:

Not a Car Question?

Question

ENGINE SHAKES LIKE A ROUGH IDLE WHEN FIRST STARTED, THEN SMOOTHS OUT WHEN HOT.CHANGED PLUGS,TEMP SENSOR AND COILS

Submitted: 651 days and 7 hours ago.

Category: Car

Value: $9

Status: AWAITING CUSTOMER ACTION

643 days and 6 hours ago.

Reply

Relist: No answer yet.

Answer

The rough idle when cold condition often means your engine has a vacuum leak somewehe that is causing it to run lean. Cold engiens cannot tolerate a lean fuel mixture. Once the engine warms up, it will run leaner okay.

My advice is to check for a vacuum leak.
This article has a lot of good tips on how to find a vacuum leak:

http://www.aa1car.com/library/vacleak.htm

If you don't find any vacuum leaks, the next most likely cause would be dirty fuel injectors or low fuel pressure.

These aricles can help you with both of these problems:

http://www.aa1car.com/library/2003/ic30336.htm
http://www.aa1car.com/library/fuel_pump_diagnose.htm

Accepts:
Expert:	Larry
Pos. Feedback:	98.7 %
Answered:	2/19/2008

Automotive technical expert

30 years automotive technical writer, editor & author

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Car