Washed Engine Bay - Strange Problem. Need The Experts

[jacobcartmill]

hey guys, i'm somewhat of a n00b on here, but i definitely am no n00b to cars. car is 92 sc400

i pressure washed my engine bay yesterday (just the edges and by the firewall as best i could) and totally tried to avoid the engine and battery and all went well. then i drove home, which is about 2 miles away, and pulled into my driveway...

the car started randomly misfiring, then it started misfiring more, then more, until it finally stalled..... i started it back up and it was running very rough, misfiring horribly, back firing, and barely running. it's just like after 30 seconds or so after starting the engine cold, the engine starts dropping the ignition signal for some reason.

1. i disconnected all of the injectors and made sure their connectors were dry.

2. i took both distributor caps off and cleaned them because i thought there may have been water in them (there wasn't)

3. i reset the ECU and the car fired up just fine (it had been off for a couple hours at this point) then started doing the misfiring again, kept doing it, it got worse, etc. just like before.

i am thinking maybe i somehow messed up one or both of my ignition coils, or possibly the ECU. the weird thing is that the car runs PERFECTLY smooth for about 30 seconds after it has sat for a while, then starts the random misfiring that progresses into running horribly, stalling, and not wanting to start... CEL is NOT on.

anyone have any ideas?

[cactuseater]

hey guys, i'm somewhat of a n00b on here, but i definitely am no n00b to cars. car is 92 sc400

i pressure washed my engine bay yesterday (just the edges and by the firewall as best i could) and totally tried to avoid the engine and battery and all went well. then i drove home, which is about 2 miles away, and pulled into my driveway...

the car started randomly misfiring, then it started misfiring more, then more, until it finally stalled..... i started it back up and it was running very rough, misfiring horribly, back firing, and barely running. it's just like after 30 seconds or so after starting the engine cold, the engine starts dropping the ignition signal for some reason.

1. i disconnected all of the injectors and made sure their connectors were dry.

2. i took both distributor caps off and cleaned them because i thought there may have been water in them (there wasn't)

3. i reset the ECU and the car fired up just fine (it had been off for a couple hours at this point) then started doing the misfiring again, kept doing it, it got worse, etc. just like before.

i am thinking maybe i somehow messed up one or both of my ignition coils, or possibly the ECU. the weird thing is that the car runs PERFECTLY smooth for about 30 seconds after it has sat for a while, then starts the random misfiring that progresses into running horribly, stalling, and not wanting to start... CEL is NOT on.

anyone have any ideas?

Do a really close check on the spark plug inserts....when the wholesale joint cleaned my engine for detailing, water was inside the area where the spark plugs are in ONE of the cylinders causing a gross miss fire and some hesitation. Water just sits in there and will not drain on it's own - you'll need to blow it out. Blow out the spark plug areas with compressed air and you my have found the culprit :) Let me know if this is the gig....best regards...

[Imzjustplayin]

I have a similar issue and did a similar thing, I am hoping there is a resolution to this issue.

[SCRider]

when my car was misfiring last year the mechanic said i needed new trac switches...but misfiring can be caused by many things...water in vacuum hoses, or possible air leakage in one of the hoses, also sparkplugs or wires could have gotten moist. Good luck with your problem because I almost had it with my 92 sc...had to replace so much crap on the freaking car, but the thing is i've replaced so many things i can't just give up now.

[eatingupblacktop]

In case you don't already know, Never pressure wash the engine! You've got water/vapour in the electrical connectors/JB's/plug inserts/sensors, etc. You now have to inspect and blow dry anything you got wet during your wash. Next time, hand wash/clean only.

[Imzjustplayin]

It's water in the spark plug holes... Around the engine there is a plastic covering where it says "V8 4 CAM 32" that covers the spark plug holes. While it does have a rubber gasket on the edges, two things are possible, 1. It wasn't installed properly so the gasket doesn't seal tight, letting water in. 2. The design is crap and no matter how it's installed, water will migrate into the spark plug holes, causing the plugs to short to ground, therefore causing a misfire.

I felt compelled to chime in because this was an issue that stumped me for some time and I didn't figure out the problem until I stumbled upon a video on youtube discussing cleaning engine bays of Toyotas/Lexus vehicles and how water likes to get into the spark plug holes.

[OkieRocket]

Can you park the car inside where a HVAC system might dehumidify your ride?