Advise Needed Misfires In Rain

[BNAZ]

Whenever I Wash Car, Rains Or Extreme Humidity My 5.0 Will Misfire And Passenger Side Exhaust Smokes Bad. Smells Like Raw Gas. It will buck and run rough. Sometimes When It Gets Warm It Clears Up. When Its Clear And Dry It Runs Fine. I Tossed The Msd Coil And Went Back To Oem. I Assumed It Was Ignition Cause Its Only One Side. I Replaced MSD Cap. Rotor And Wires With Ford 9mm Wires And Motorcraft C/R. Also Pulled Plugs And Replaced W/motorcraft. I Only Did Pasenger Side Cause That Was Side That Smoked. What Else Could It Be.
The Car Does Still Have Original H Pipe W/137k. New Magnaflow Catback About 15k Miles Old. Help

 

[BNAZ]

I welcome and appreciate any suggestions.
I was wondering also if the o2 sensor on that side was faulty would send bad signal for one side of engine ?

 

[ms93gt]

Do you have the distributor boot on? If not then theres your problem.

 

[BNAZ]

I put the Dist boot on with the MSD coil and it still smoked and bucked.
I thought that also

 

[Wknd_Warrior]

Where is your air filter?

 

[MrKwik]

Where is your air filter?

That was going to be my first question. One of my cars was acting all goofy in the rain and would buck and miss and even died at stop lights a couple times. I traced the problem to the fact that it had a removed silencer and I had not bothered to put the plastic inner fender in when I reinstalled the passender side fender. The tire was throwing all kinds of water into the airbox. It ended up costing me a new MAF.

 

[BlackFox5.0]

At night, get a spray bottle with water in it. spray down your wires and asround the cap lightly, then start the engine. It has to be dark out so you can see if any arching is going on. You might see some sparks coming off your wires, if thats the case, then there is your problem.

 

[BNAZ]

The air silenser is off. I have a K & N inside stock filter box. The car will do it by just being in ran for exteded periods. It only smokes out of one pipe only.
Also the wires are brand new.

 

[ss93cobra]

I'm with BlackFox5.0 on this one with the spray bottle effect. Also though, use it on the harness plugs near the pass. side shock tower under the air filter inlet tubing as well as looking at the harness under the car for the pass. side O2 sensor. Perhaps water is getting in there from the rain and causing your concern. I'd seen your post the other day and thought about it. Considering what all you've changed, an obvious answer isn't there. You're going to have to spend some time to track it down since the car is in front of you and not us. Where ever water can get is where you'll need to look. Start out by BlackFox5.0's suggestion though, start it up, soak it down a little at a time to see what you can find. Good luck to you.

 

[BNAZ]

Thanks guys. I will try water bottle test. The first time this ever happened was at car wash. I sprayed down undercarriage well to remove road salt and the thing smoked and bucked worse than ever. Again the heavy white smoke only came out of pasenger side tailpipe. I was thinking about th o2 sensor.
But wasnt sure if it would affect one side of motor only. I dont know the wiring. We've had some 95% humidity weather and it smoked and bucked at start up. Thanks again. If any thing else come to mind feel free to suggest it.
Thanks

 

[ss93cobra]

So the first time it happened was when you'd washed the undercarriage then?
I'd start with that. BTW, hope I didn't sound like a smart ass either...

 

[BNAZ]

I take all replies objectively. no problem sscobra93. Remember I'm looking for help. Actually at the carwash I washed the entire car and the undercarriage. What I just thought of was even when I do a wash it at home w/ low pressure hose not spraying undercarriage, the problem happens almost immediately. I'm just looking for help.
Thanks again

 

[jerry beach]

A buddies car was doing the same crap. He would unplug the MAF sensor and the problem would go away. Try that, its a good temp fix if it makes the engine run right. We tested the MAF, wiring and MAF circuit in the puter and all were good. Then we ran the engine till the problem started happening and tested the puter again. It tested bad and was replaced. His only did it on humid or rainy days also, it ran fine in dry weather. I took the puter apart and there were no signs of water damage in there either.

 

[ss93cobra]

Let us know what you find.