Changing spark plugs

[T-Marley]

Ok...

The back of my prelude looks like a pair of underwear with horrible skid marks, if I ever go above say...6000 RPM my car smokes and a carbon like film (as opposed to an oily like film) gets plastered on the back. Anyone have any ideas as to what could cause that?

I read somewhere that it could just be fouled spark plugs, so I went in to replace the spark plugs....and when I took the first spark plug out, oil dripped off of it. I think the oil might have been sitting above the spark plug so that when I took it out it looked like it was dripping out of it, but this doesn't seem possible as there was no oil or oil residue on the plug wire when I took it out. But I'm also thinking that if I had such a huge problem that my spark plugs were just sitting in oil, then my car wouldn't still be driving like it was.

Regardless, I replaced the spark plugs, and it doesn't smoke as bad, but still does nonetheless, and needless to say it's hard to keep a spotless machine when it takes a crap when you need to pass someone. And plus I haven't hit my VTEC in a while and I'm kind of missing it

By the way, it's a 1996 Prelude VTEC with CAI, oversized pulleys, and for some reason the guy who had it before put an Apex'i V-AFC in it, but I haven't touched that because I don't want to mess anything up.

Any ideas would be greatly appreciated!

[spiffyguido]

As for your plugs, any oil that is actually inside the combustion chamber would get burned away, so if you plugs are dripping oil, the oil must have been sitting on top of them. This can be caused by bad seals in the valve cover. Your bottom of your valve cover has 4 seals that are supposed to prevent oil from seeping into the holes for the spark plugs.

If I were you, I'd take your valve cover off and make sure those 4 seals are in good shape. If not, get new ones. You don't want your plugs to be bathed in oil all the time. That might cause plugs to foul, etc.

As for the skid marks on the back of your lude. It sounds to me like your car is suffering from some incomplete combustion, hence all the soot it is spitting out the back. I had a white lude once with the same problem, and it was always a mess to clean up. My guess is that your car might be running a little bit rich, or something else is preventing good combustion.

One easy way to tell if a car is running rich is to just start the engine, then stand near the exhaust. If you smell gasoline, or the exhaust makes your eyes water/burn, then chances are, you're running rich. Run some fuel injector cleaner through the car, and check the condition of your injectors. You don't want one dribbling a little too much fuel into the intake port.

I'd also check that you're using the right spark plugs. Honda suggests particular brands and gaps for various types of vehicle use. You want to make sure the plugs that you are using are of the right heat range and are properly gapped. If the fuel/air mixture isn't igniting properly, you'll be getting crap belched onto the back of you car for sure.

I suppose another possibility to your troubles is that your car is simply burning up a lot of your engine oil. This can often be caused by oil getting by the piston rings into the combustion chamber. A compression test can be a good way to check the condition of your rings. If your engine puts out a lot of blue smoke under heavy throttle, I'd start to suspect that your rings were worn out.

Another reason your engine might combust oil is if your PCV (Positive Crankcase Ventillation) valve is worn out. This is a $10 part from Honda, and they don't last forever. A bad PCV valve will let more oil pass from the valve cover to the intake than it is supposed to. If you yank your CAI off and find that the inside of the tube is coated in engine oil, that's a good sign that the valve is faulty.

Do you mean that you can't hit VTEC? VTEC is (among other things) dependent on oil pressure, and if your lude is burning oil (and therefore low on oil sometimes) then it is very possible your VTEC won't engage as it should. I saw this very condition on a friend's 94 Lude SR-V. Top up your oil, let the car warm, then try and find VTEC. If VTEC suddenly works, it's probably an oil problem.

I hope this helps. Hit us back for more details so that we can help you get your baby running like a charm again. I remember you from HPOA, and it's nice to have you here. Tell your Lude'n friends to stop by!

[RedRacer]

Well, Josh is just sitting here with his mouth open....and nothing to say. Because SOMEBODY else had to go and blab everything he would have said!

Thanks SPIFF! Suck all the fun out of everything I try and do why don't ya?

OF course I am JUST KIDDING!

T-Marley, it's great to have you here posting on PDriver. Awesome! Glad to have you. Tell your friends and any of the old gang from HPOA that you may be in contact with. We'd love to see a return of familiar fac....uh, usernames!

As for what this could be, I would land on the two prime points that Spiffy has already stated.

1: O-rings around the plugs are probably leaking. Very common condition.
2: The engine is running rich.

Check up on what has been stated and see what you can find.

Oh, the right plugs. Very important. I hope you got NGK's for the car. That's what it needs and that's really all it needs. For VTEC you want the PZFR6F-11 NGK plugs. They're platinum, so they're not cheap, but you shouldn't be replacing them very often, so it's all good in terms of cost.

Let us know what changes or doesn't change. We'll help figure it out.

Josh

[T-Marley]

Yeah actually, I was sure to get NGK plugs from what I remember reading on HPOA back in the day. Was pretty pricey, but nothing's too much for my lude

To Spiff, VTEC still works just fine, I've just been avoiding it as much as I can to try and take it easy on the engine until I can get it back up to 100%.

Also, I took my CAI out and it was clean inside, so I suppose that means that chances are going to be the valve cover gasket. Though with my luck it's probably a combination of like 50 little things

Will probably take my valve cover off this weekend and see what I can dig up, will let you guys know on Monday what I find out.

Is it possible that perhaps the person who put the V-AFC in the car didn't know what they were doing and just programmed it wrong so that it is running too rich? I haven't touched the programming side of that thing since I got the car, because I know that I don't know enough to try and program something like that.

I wish I could find more people from HPOA and shoot them this way, but the way it just kind of disappeared without warning didn't leave any time to grab e-mail addresses or anything.