I have a '93 del Sol SI and for the past few years it's had a very rough idle, bouncing between around 1k rpm and 2.5k when the weather is normal to hot, and occasionally between 2k and 4k rpm when it's cold out or the engine is cold.

Lately I've been having a serious stalling problem. Once my engine is warmed up, the idle still bounces between 1k and 2k but it seems like a slower fluctuation, and at what seems to be random times when my car is on, my car will drop rpms, throw a check engine light and stall. Usually if I turn the car off for a few seconds and try again, the CEL goes away and my car will start again until it feels like stalling.

It's stalled while I was sitting at a stop light. It's stalled while I was pulling onto a main road and about to shift into second gear. It's stalled while I was in 5th gear driving down a main highway with my foot on the gas. (It was easy to restart then, probably because my car was rolling so fast.) There's no check engine light except for right before it's going to stall, and only for a second or so.

I've changed spark plugs, spark plug wires, distributor cap, distributor, and fuel filter. I have a cold air intake on the stock hose for the air box, which may be a culprit for the original idle problems (which are more annoying than anything), but the stalling issue is new as of the past week and a half. This is driving me nuts as I can barely make a 15 minute drive to work without it stalling on me at some point during the trip.

I don't know what to fix or where to look, as I don't even have a CEL going to check for that. Help would be greatly appreciated.

txgreasemonkey

It may be a bad Ignition Control Module (ICM) or coil inside the distributor. ICMs are particularly problematic on Hondas. If you want, AutoZone will test both of these items for free. Personally, because of the age of your Civic, I would replace them. Here's how to do the work yourself:

http://www.askmehelpdesk.com/cars-tr...tml#post265896

This will likely solve your stalling problem.

Here's what the ICM looks like:

While we find your parts, please enter your ZIP Code at PartsAmerica.com

To ensure your ECM is O.K., perform the K-Test:

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multi-meter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it’s probably indicating ECM failure. Most failed ECMs will record a fraction of a volt. To me, the K-Test is simple, elegant, and accurate.


This would be a good time to replace the rotor, while you have the distributor open.

Xxtayce

I took it to a mechanic because it was stalling so badly that I wasn't sure I could get it to Autozone to get the parts tested. Mechanic says I have a bad distributor (I just replaced it two and a half years ago!) and a bad Main Relay for the hard start when the temperature outside changes. I think he's still clueless as to why my idle surges, though.