Hi guys, my car started running rough. Brought it in to Simone Performance and Vic had it checked right away. The code that came up was Multiple Cylinder Missfire.

He was concerned about water in fuel, but it happened over two tanks of Shell Premium. The first time it happened, I turned the car off and back on and it cleared the error and the problem. The second time, I did the same thing. Third time it started while I was driving, tried restart, but didn,t work.

He thinks it might be a wet connection somewhere. We had a lot of rain lately in Toronto and GTA. I was only driving in it once. Otherwise, the car was sitting in the rain.

Anybody got any ideas about this?

Thanks,

Mark

 

How many miles on your car? What service has been done on it?

 

About 60,000 K on the car. I have a High Capacitive Discharge Ignition box from Stillen that's been on for 3 years. The car has never had a problem like this. Plugs changed last year.

I have a AEM long CAI, also been on for three years.

This is defiantly more than one cylinder not firing.

Monday, I was on the highway in stop and go traffic, and it happened. After about 3 minutes, it cleared up.

No rain that day, but the day before it rained, but the car was sitting in the driveway.

Thanks for any help.

Mark

 

You may have a camshaft or crankshaft sensor going bad. Sometimes thier are pending codes which will not lock in the check engine light. Depending on the service centers scan tool it may not pick up pending codes.

I had a similiar problem which ended up being some bad coil packs. I have low mileage and the custom stainless valve covers were the culprit for the early demise of the coils. I have since had the covers louvered to prevent overheating coil packs.

 

The only code that came up is "Multiple cylinder Missfire" Vic cleaned the crank sensor, but nothing else I know of. I had crank sensors go on other vehicles, and it does sound like it might be it.
I'm going to disconnect the Capacitive Discharge and run it for a few days.
Vic was able to get a code, but it is so vague. There is still a number of things it could be.
Trial and error gets expensive.

Thanks,

Mark

 

Could be water seeping in through the main harness boot onto the ECM. I'm assuming you had some extra wiring pushed through it (thus the leak)? Seen this happen way too many times.

 

I opened the AEM Long CAI yesterday and there was traces of muddy water at the connection just before the first sensor (Mass Air?) I cleaned the tube and installed a AEM Water Filter.

I think I should clean that sensor as well. Will wait for more info.

The next thing I'm going to do is put Dielectric grease on all the connectors I can get to.

I'm wondering about the HKS Capacitive Discharge Ignition box as well. There is a small red LED on the side of he box. I need to find out if that a warning light of some kind.

The unit was plug and play, but I will check the connector at the ECM.

Thanks,

Mark