Engine misfire after engine wash
Thread Starter
Driver School Candidate
Joined: Jan 2010
Posts: 24
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From: ca
Engine misfire after engine wash
I pressure washed my engine bay and after the engine started to misfire, I did some research on clublexus and found a lot of ppl had the same problem. I found water is the spark plug areas, so I took off the intake manifold and cleaned up all the water. I replace the spark plugs and the wires and the ignition coil, and the engine still seems to misfire but not as bad as before. Does anyone have any idea wut could be causing the problem.
Thread Starter
Driver School Candidate
Joined: Jan 2010
Posts: 24
Likes: 1
From: ca
The distributor was covered prior to pressure washing, after I removed the cap and it was dry, and the wires are all brand new, car has been sitting for a few days and everything seems to b dry, but engine still misfires
Lets hope its just moisture in the dist, you don't want it to be anything else. I had a car, despite the hood being closed. When I rained, the car wouldn't start. Wait a few hours til it dried out, started right up. No visible moisture in the system at all. I took everything apart, sprayed some water proof junk on it and worked fine.
I would lightly drive it til the engine gets up to temp, or just let it idle for a little bit @ $3.00/gallon 
You don't need much water under the boots of the plugs to mess you up. If that doesn't work, download the manual. Its a searchable pdf... Google will also help out a little more than this forum
You don't need much water under the boots of the plugs to mess you up. If that doesn't work, download the manual. Its a searchable pdf... Google will also help out a little more than this forum
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IT is water in the spark plug shafts that is causing a ground between the outside of the spark plug and the engine. You could let your car sit in the hot sun for a while so it evaporates, or you could gain access to the spark plug tunnels and use compressed air to get it out.
I wouldn't drive it if this is the case. It will drive bad misfiring(not good at all), and the engine will not get hot enough at a quick enough rate to evaporate the water that is in the spark plug tunnel. If it does not idle harsh then start it and let it sit idling while keeping an eye on it. This way the engine will not be under load while misfiring, which equates to far less strain on the motor.
I wouldn't drive it if this is the case. It will drive bad misfiring(not good at all), and the engine will not get hot enough at a quick enough rate to evaporate the water that is in the spark plug tunnel. If it does not idle harsh then start it and let it sit idling while keeping an eye on it. This way the engine will not be under load while misfiring, which equates to far less strain on the motor.
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Thread Starter
Driver School Candidate
Joined: Jan 2010
Posts: 24
Likes: 1
From: ca
Aight, so I took off the intake manifold and removed all the spark plugs and wires, cleaned it all up again and put everything back together. Started up the car and it seems to have a slight misfire and hella black smoke coming out of the muffler. I let the car idle and it idles at 500 rpm and a slight misfire. What else could it be?
Driver School Candidate
Joined: Nov 2010
Posts: 20
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From: Florida
500 rpm
500 Rpm.. is that slightly below average.. for a cold start, I adjust mine to 900 rpm average for the cold season to not misfire. I recall I remember having the rpm were your set is, the engine was having trouble to keep on stable.
But that just my theory.. I wouldn't want to say the problem is because your Rpm might be too low.
But that just my theory.. I wouldn't want to say the problem is because your Rpm might be too low.
Driver
Joined: Nov 2008
Posts: 112
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From: tx
First off, don't ever do that again. "Washing" an engine is never a good idea with a car depending so much on electronics unless you plan on afterwards disconnecting every single electrical terminal or taking the wiring harness out and drying all the water out of it. Even on a non-electronic carbureted engine you'll 9/10 times have to do the same and will get water in the dist cap or water log the wires/connectors since they're usually not waterproof. I've seen this scenario WAY too many times, good luck getting it running right again, best bet is to pick up a can of Wire Drying spray from the car parts store along with some compressed air, and go through EVERY connector and dry them all out. Hopefully you didn't short something out that drying alone won't correct. In any case if you don't dry all the connectors out, rust could get introduced and a few years down the road now you'll have even more problems. Hope you've learned your lesson! Same goes for everyone else, do not wash your engine unless it's out of the car with the wire harness disconnected.
Thread Starter
Driver School Candidate
Joined: Jan 2010
Posts: 24
Likes: 1
From: ca
You aren't scaring anyone buddy, I'm just trying to get suggestions of what my problem could be, I appreciate all of your inputs, and thank it guys. I jus need to do some more trouble shooting and keep you guys posted.