Accordguy
Dec 9, 2006, 09:18 PM
Hello, my sister has a 1999 Honda Accord Coupe EX with the 2.3l VTEC, 5 spd. Awesome car. 200k. The main ignition relay was promptly replaced in the summer. No engine light.
Lately, the idle control is unstable. When the car is cold and you approach a corner and push in the clutch without throttle, the car drops past idle and stalls. It seems to operate normally when the engine is warm.
1. Does this car have a IAC valve (Idle Air Control) that boosts idle when engine load is added such as AC? Is this behaviour a likely failure mode?
2. Another post in the forum suggests a weak fuel pump after 140k. Is this idle instablility a likely symptom of that considering that the car runs great at high RPMS?
3. Does this car have a thermo-wax fast idle air valve like the older Accords to increase air flow when the car is cold?
4. Can a dirty/faulty mass air flow sensor cause this behaviour? How about a MAP sensor?
5. Honda has posted a safety recall for ingnition key cylinders for these cars. The previous owner ran the VIN# at the dealership and it was not flagged for the recall. Could this be relevant?
6. The EGR systems on the older Accords contribute to idle instability. Are carbon clogged ports an issue on the '99 Accords?
The car has been very well maintained. It just passed an emissions test like it wasn't even running which makes me think the EGR system is just fine.
I guess it couldn't hurt to change the fuel filter as well.
Any suggestions would be appreciated.
Lately, the idle control is unstable. When the car is cold and you approach a corner and push in the clutch without throttle, the car drops past idle and stalls. It seems to operate normally when the engine is warm.
1. Does this car have a IAC valve (Idle Air Control) that boosts idle when engine load is added such as AC? Is this behaviour a likely failure mode?
2. Another post in the forum suggests a weak fuel pump after 140k. Is this idle instablility a likely symptom of that considering that the car runs great at high RPMS?
3. Does this car have a thermo-wax fast idle air valve like the older Accords to increase air flow when the car is cold?
4. Can a dirty/faulty mass air flow sensor cause this behaviour? How about a MAP sensor?
5. Honda has posted a safety recall for ingnition key cylinders for these cars. The previous owner ran the VIN# at the dealership and it was not flagged for the recall. Could this be relevant?
6. The EGR systems on the older Accords contribute to idle instability. Are carbon clogged ports an issue on the '99 Accords?
The car has been very well maintained. It just passed an emissions test like it wasn't even running which makes me think the EGR system is just fine.
I guess it couldn't hurt to change the fuel filter as well.
Any suggestions would be appreciated.