Rough Idle Question

[MaWeiTao]

I have a 1999 Prelude, non-SH. Quite some time ago I got a check engine light. I pulled the code and it indicated a problem with the CKP/TDC sensors. Despite that the car ran fine.

Last week I found the car to be idling roughly; it's RPMs were lower than they should be. Once I got home, with the car sitting in idle the check engine light started flashing. I checked the code again and it returned the same one for those sensors.

So I finally had the sensors replaced. As I approached home the check engine light came on yet again and when coming to a stop the engine was idling roughly. When sitting at home I revved the engine slightly; it hesitated a bit and the revs then dropped back and the car died. I am still able to start the car and drive it around.

The thing to note is that the car is fine when cold; it starts idling roughly when it gets warm. When driven the car seems to run more or less fine; I get the feeling that it isn't quite right, but the problem is really only exhibited when I come to a stop and the car is idling.

I am hoping someone has any idea what might be causing this. Any advice would be appreciated.

[sofast]

I had the same codes with a prelude at work a few months ago. i went through a flow chart that started with replacing the sensors. Then checking resistance on the sensors because replacing them didnt cure the problem. I ended up replacing the ecu and it was corrected.

Did you pull codes the last time the check engine light came on? The TDC shouldnt make the car run like crap. Im thinking its time for a Plugs, wires, cap, rotor and a fuel injection service.

[MaWeiTao]

The plugs and wires are only a little over a year old. However, I'll take a look at that stuff; it may well be one of those things.

[MaWeiTao]

Every time I've checked the codes its returned the same one; 8, for the CKP/TDC sensor, including just yesterday.

[sofast]

Originally Posted by MaWeiTao

Every time I've checked the codes its returned the same one; 8, for the CKP/TDC sensor, including just yesterday.

Sorry man. I was busy at work and forgot to get a flow chart for you. I will try again tomorow. There are a few people on vacation so its been kinda crazy at work.

What kinda plugs and wires did you use. If you didnt use NGK then you need to. That is what the honda recomends. Some people try the Bosch thing and turns out to be more money in the long run because they have to replace it with NGK a year later

[MaWeiTao]

The plugs and wires are NGK. I went with what was recommended. I just changed the rotor and distributor cap today. The one I replaced was old, but not too bad.

In the end it made no difference. I still have the same exact problem. I took a look at the ignition coil for the hell of it and the resistances were fine for that, all within tolerance.

It would be great if you could find those flow charts when you get a chance. Actually, I have the helm's manual, do you think they could be found in there?