Q: 1999 Honda accord. Idles up and down. Will start cold, runs great. Try to restart warm, won't. Floods.

asked by on

A lot has already been done to try to pinpoint this issue, but not by myself. I know fuel pump regulator, filter etc.. I was wondering if the main EFI relay could give these symptoms? Its only 50 bucks, but wanted to ask before I did it. Plugs are soaked. Runs excellent after it starts.idles up and down. Give a little gas and it purrs. If its shut off after running awhile it will not start until cooled down.

My car has 134000 miles.
My car has a manual transmission.

This problem of erratic idle speed is often referred to as "surging" or "hunting". The causes include a faulty idle air control valve or circuit (IAC), a faulty ECM (not common), faults in the fuel pump control circuit, defective spark plug(s) or ignition system components, faulty fuel injector(s) or injector circuit faults, and PCV system faults. Often, the application of a real time automotive scanner can find the fault as actual engine operating parameters can be viewed during the "surging". I would recommend that you request a rough operation/rough idle diagnostic and the responding certified mechanic will perform the required diagnostic steps to get this resolved. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. 1999 Honda accord. Idles up and down. Will start cold, runs great. Try to restart warm, won't. Floods.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: Problems with idle

Unfortunately, this is something that older cars suffer from. Vacuum lines are made of rubber. Over time, the rubber in the engine compartments begins to get hard and brittle. Once this happens it no longer performs its job properly and...

Q: Issue with firing - 1991 Volvo 240

Misfires can occur from fuel supply, spark, and camshaft timing problems. You have replaced most of the ignition components that supply spark to your cylinders, but you could still need spark plug wires. They may look good and not be....

Q: Trouble starting, misfires, dies when you let off the gas.

It sounds like you have a real bad vacuum leak. After you replaced the radiator and hoses to get it running again check all the vacuum hoses to make sure there is no broke hose. If you find there...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.