CT ITALIAN 1

iTrader: (2)

Today I was driving home from work in heavy rain when my Z began to start acting very funny. It started to like buck and the idle was dropping very low (under 500). The lights even started to dim at the low idle. When I got home and parked in the garage, the check engine light had come on for a brief period of time. This has happened before when I went through an auto car wash but went back to normal shortly after as I expect it to do this time around. I'm just curious, what is causing this?

2001NBMZ28

Dunno - but if the SES came on even momentarily there should still be a code in history - might've just been for a misfire, but maybe it'll give you a clue.

Peppershaker

Wouldn't say for sure but would bet if the water you ran through was deep:if you look at were the wire go into the back of the plug connector on your O2 sensors they are not sealed air tight and have gotten moisture in the plug connector and are not making good contact and raising the resistance giving a wrong voltage reading to the PCM. Had this happen to me here in Florida after driving through some deep water in a low area after the hurricanes came through 2 years ago. Had pulled the connector apart and see moisture inside the plug connector. Took a hair dryer on low temp so I made sure wouldn't hurt or melt any thing and dryed them out and then took some O2 save silicone and sealed the back of the connectors were the wires go in. Didn't have any more problems after that. Hope this helps.

2K2WS6TA

iTrader: (2)

What happenedw with mine, I washed the engine, and got the same thing you did driving thru water.
I figured that water got in the alternator, and made it act weird for a min, once the alt dried out it was fine (and its been working fine ever since)

CT ITALIAN 1

iTrader: (2)

It's been fine ever since, I think water just hit the optispark.

SladeX

but there's no optispark with a ls1...

CT ITALIAN 1

iTrader: (2)

hmm, that's just what another forum member had told me. I really don't know then haha.

JL ws-6

iTrader: (50)

it's a car, not a boat.

coolformula

iTrader: (21)

somebody install a cam and didn't tell you....that would cause the lope lol

CT ITALIAN 1

iTrader: (2)

haha, it's done this a few times. I'm still curious as to what's causing it.

SladeX

I'm guessing alternator got wet, everytime I go under the car I always think that's a horrible place for an alternator...

CT ITALIAN 1

iTrader: (2)

ya this happens pretty much everytime I drive in any amount of substantial rain, which I've been trying not to do lately since my new paint and stuff.