Well we had one hell of a down pour of rain over here at the weekend, I was practicly trapped in my town by a puddle at each end... I decided to take what looked to be the shallowest.

Now I went through at a steady pace, but it was enough water that I had it sploshing out of the gear leaver hole and into the car... a bit deeper than I thought!

The car started to missfire as I was going through but I kept it alive by opening the throttle. I had around a 10 mile drive to do and by the end of it the car seemed to be back to normal with only a very slight missfire although it had set a code 44 (Lean O2 Sensor) but I would assume that this was because I had a missfire.

Took it out a day later and it just seemed to get worse and worse, it would clear with lots of throttle and revs to start with but then it would missfire all the way through.

I've replaced a couple of plugs that we're overly fouled up, again I'm guessing that these were the ones that I lost going throught the puddle...

I've taken the Cap off and wiped it out, taken all of the sensor plugs out to check for water (TPS, IAC, CTS ... ETC)

I'm a bit lost now! I wonder if maybe driving the O2 sensor into cold water has damaged it? I can tell that I'm getting a voltage from it, it says LEAN when its obviously rich but a Missfire is always going to show as Lean anyway...

HELP?

 

What year?

 

1985, 1992 ECM (MAP not MAF)

I should probably also add that I'm running a SMALL cap distributor and External Coil

 

Just let the thing dry out for a few days...before you get too far into it. You have what is called a "wet vette". Come back to it in a few days. I'm surprised the thing didn't short out totally while you were in the puddle.

Good Luck

 

OK well yesterday I took all of the plugs out and cleaned them up, all of them we're very black but came good with a bit of cleaning.

I put them back in and started it up, it was a lot better before but again still felt as if it was down on one cylinder. It smells very very rich...

I took it out for a 20 mile drive, around town it was useless... not trying to keep itself alive and really sufferd from the "cam"... on power is another story though and its still pulling like a train! The longer I could stay at WOT the longer is seemed to be better after I came back down to normal driving.

Again i got a code 44 - lean O2 sensor. I know its not often the sensors fault, but I'm wondering if it could be in this case? The O2 Sensor would have no doubt have been submerged under water when I went through the puddle. The O2 sensor is also not used when at WOT, which is another thing that makes me think its that.

 

I have an 85 and the 02 is easy to replace Use a 7/8 wrench and get it drom the bottom it is about a 20 dollar 20 min job. also dont forget to re set your codes. good luck cause mine is running like poo

 

I'm actually running an LT1 exhaust and the probe is tucked up near the gearbox which makes it a bit of a pain tbh more to the point though I don't see the point in just chucking parts at it I'd like to try and diagnose the problem.

A heated O2 sensor here works out at $120 or £60 my money...

 

Might be a pia, but I think you should pull the 02, believe you can ohm test it........not good getting any electrical parts or sensors wet. Good luck. Unless you can scan it.

 

I have done a scan on it, and it shows a lean voltage on the O2 - but there is a missfire and the O2 sensor will see a missfire as lean - so it could well be telling the truth.

I think I'm going to have to swap it out just to be sure I guess...

 

I would too. The O2 can be fouled in a similar way as the plugs. When this happens it gives a false reading to the ecm. Good chance you will kill another set of plugs if you keep driving it.

 

I took a load of fuel out on the tune and the engine came smooth and running nice again, the lambda still came up with a LEAN code - but it obviously wasn't...

I reset the ECM, reloaded my custom tune, installed a new Lambda and a new set of plugs...

AS GOOD AS NEW

Well for the time being at least