93 Impreza, Looking for a little direction if someone can help.

[schekan]

It's been a while and I know there is a lot of knowledge in these forums so I figured I’d ask.

I have a 93 Impreza, 310,000 miles. Well maintained and working great until today.

I was on the highway (pouring rain) and it seemed to sputter like I had a fouled plug, it then would not rev past 4000 rpm, and then stalled out. I pulled over and tried starting it but it would just start/sputter at 1000 rpm then stall after a few seconds.

I called for help and while it was on the way I kept trying. I opened the hood and checked the wires and electrical plugs that where accessible for a good connection. I thought maybe something got wet. It still would not start.

I decided to try spraying the Mass Airflow Sensor with brake parts cleaner to see if it would help. After a couple tries it started and I drove it 60 miles home without a problem.

The only code stored in the ECU was 24, the IACV.

Could the idle air control valve cause something like this to happen? Or maybe water made its way through the air cleaner and got the MAS wet?

Any ideas would be greatly appreciated.

Thanks.

[edrach]

I don't see why the IAC would do that without throwing a check engine light. I sometimes have trouble with a fast idle on my Impreza and I throw in a can of seafoam with a full tank of gas and the fast idle goes away after a couple of days and doesn't come back for 3 months or more.

 

I would consider cleaning the MAF with a true MAF cleaner (I bought mine at NAPA) since that seemed to work this time. It's also possible the connector to the MAF was loose or had a bad contact, but that should have thrown a code and didn't.

 

I have some LPS (brand) greaseless lubricant that displaces moisture. I've used it in the past to spray on the wiring and distributor cap of my Brat since they were subject to issues when wet. It might prove useful to your Impreza also.

 

Lastly, if the ignition wires or ignitor on your Impreza are more than 100K miles old, it might be time to replace them (wires first, ignitor next time you can score a lower mileage one at the junkyard).