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Hello, there. I drive a 1992 Civic VX hatchback and I removed some recently installed spark plugs after the idle started feeling ‘rougher’ than normal. All 4 plugs had this distinguished discoloration on them. The plugs seen here only have 4,000 miles or so on them. I did use a bottle of Red Line SI-1 fuel system cleaner about 1,000 miles into use with the new plugs. Engine has over 260,000 miles, and needs a clutch replacement.
http://img828.imageshack.us/img828/1763/1003554.jpg
http://img153.imageshack.us/img153/3654/1003550.jpg
http://img854.imageshack.us/img854/8595/1003553d.jpg
The car seems to have a lug at idle. The plugs pictured were replaced with new NGK of the ‘correct’ OE part number.
So far the following has been done:
IACV/EACV cleaned 1 year ago(it had the ‘hunting’ idle problem)
EGR valve and ports cleaned
Timing belt/water pump replacement + their seals replaced + drive belts replaced
Valve lash adjustment performed 1 year ago
PCV valve replaced
Spark plug wires replaced with OE Sumitomo wires
Distributor cap and rotor replaced with OE parts
Replaced Fuel Filter(twice, once with WIX and now with a Purolator)
Replaced 02/LAF sensor(was sending code 48) with aftermarket 5-wire sensor
Using Amsoil 0w-30 oil and Amsoil Synchromesh MTF(5w-30 range viscosity)
Valve cover gasket replaced(including spark plug tube seals)Not related(both drive axles and inner/outer tie rods + belows/boots replaced as well).
Could worn engine mounts be possible? The shifting seems to be ‘somewhat’ dramatic, but the clutch ‘is’ worn.
Need to remove breather chamber for inspection. Old PCV valve was probably the original and looked like this when replaced:
http://img193.imageshack.us/img193/1255/1003458h.jpg
The engine loses about 1 quart every 3,000 miles. 40 MPG combined fuel economy.
The idle seems to just be uneven/slightly rough for some reason, as opposed to just being smooth. The hot idle that is. I haven’t checked the Fast Idle Valve since it seems to go up to 1,500 RPM on the colder starts and settles down when warm.
I’ve cleaned the Throttle Body at least 3 times since owning the car now. I use a K&N drop-in air filter and run on 87 octane mostly.
The RPMs when hot seem to dip below the ‘lower’ RPM marking(the one that ‘represents’ 500 RPM). It happens mostly at the moment of extra electrical load, like AC compressor kicks on OR a cooling fan comes on. The idle adjusts up and gets smoother, but upon ‘settling’ again it seems to be rough at readings of 500 or even lower; if that even sounds right because it suprisingly appears lower than the 500 RPM mark at times.
Maybe someone changed the idle speed screw from a Previous Owner(purchased the car at 230,000 and have been trying to get all maintenance caught up)???
Thanks for any help, tips, advice. etc.
PS: Have recently posted on ericthecarguy’s youtube page about idle issues with a 92 Honda Civic HB and was directed here more or less. The clutch needs replacement and probably the Input Shaft Bearing as well. Just found out recently the master cylinder at the clutch pedal is beginning to leak internally.
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It sounds to me like you’ve got an abnormall ylow idle speed, which is causing your stumbling problem. I imagine that there is an adjustment for the idle speed, so you can raise it a couple hundred RPMs, but I’m not sure where that adjuster is, or if it even exists. It stands to reason that you could use the throttle cable as the adjuster, I know that Eric posted a video on how to adjust that cable, maybe you could use that to hold the throttle butterfly open ever so slightly, just enough to keep the idle speed around 750-800 RPM. I’m just guessing here, so it’s quite possible that I may be completely off base, but it sounds logical to me.
The idle adjustment is factory set and should be left alone. perhaps a previous owner did mess with it ( was the low idle speed situation there when you first got the car ? ) you might want to look for a poss. vacuum leak.
Thanks for the replies.
I did spray various vacuum hoses along the Intake Manifold. I will have to look but I don’t remember seeing the ‘permanent’ plug(if that is what you would call it?) for the idle speed adjust.
I can’t honestly remember if the idle went into lug mode like this when first driving the car nearly 2 years ago. It shows itself whent he engine is hot. So either the idle control devices/influencing parts are wearing(of a management sort)
OR there is bottom-end wear like bearings(?) that could be allowing for the oil pressure to get low enough to cause the idle lug. I may have to up the grade of oil. If it WERE bearings begginning to go, I’d hope to catch it before true mechanical malfunction occurs and partial rebuild of the bottom-end at least.
That is the worst case scenario.
So you know, this car only has an oil pressure switch(or OPS…dummy light), so I haven’t checked actual hot idle oil pressure readings and compared them to factory. That is another possibility.
Still, if the idle is EXCESSIVELY low by another means, ‘could‘ that allow the oil pressure to drop by lugging the engine down to 300 RPMs or so etc?
PS: Any value in perhaps looking into replacement of the fuel pump ‘sock’ in the tank?
You might want to do a fuel pressure check. possibly even a compression test just to see where you stand there.
Quoted From 619DioFan:
You might want to do a fuel pressure check. possibly even a compression test just to see where you stand there.
Is there a schrader valve/fuel test port to hook a gauge up or do I have to manually rig a pressure gauge in at the fuel filter(if so do I test from the line IN to the filter or the line OUT ) ?
Right after purchasing the car almost 2 years ago we compression tested the engine ‘warm’, but not ‘hot/full temp. It passed compression testing.
Maybe a leak-down test instead could reveal some bad exhaust vales, etc?
I’m pretty sure the clutch is the issue, the engine felt bogged down tonight in all of the gears. Let off of the accelerator and it feels like the engine has a ‘clunk/rocking’ like settling in, like when you rev the engine in neutral while idling and the engine jolts forward some and then settles back? That sort of rocking feeling happened each time I let off of the accelerator tonight.
Almost feels like the catalytic converter is clogged, power wise.
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