Ok here's what happened. I went to wash my engine bay out this afternoon. I put bags over the fuse box, intake filter, dizzy, and alternator. I applied the engine cleaner and washed it out pretty good. Now I'm looking at the motor and it looks awsome. I crank her up and everything is peachy. As I make my way down the road I start to notice my engine having problems reving. Now it idles at under 1000RPM where before it was around 1100, and when I put my foot on the gas it doesnt want to rev at all.


I slowly drove her home and on the way the check engine light came on? Have I ****ed something up bad or is it just water? What should I do?

 

Try taking pressurized air (hoping you have an air compressor and not those wimpy 'bottled air' bullcrap), and blowing out the connectors for the idle air control valve, map sensor, throttle position sensor, etc (maybe just do a solid work-over on everything, crevices and all).

Check your throttle cable (make sure the problem is still evident by turning the throttle plate by hand and not by the use of the gas pedal).

Does the engine fail to rev or is it possible that the clutch is slipping? (there is an open port on the topside of a lot of manual transmissions that allow airflow and cooling, water / cleaner may have invaded the clutch assembly)

Check your spark plug boots to see if any fluids got down in there.

Oh, first things first, check your cel code to see what it yields.

 

man its idleing at 800 and droping down to 700 every now and then... runing real ruff and wanting to shut off?:

 

You might have gotten water in your spark plug tubes, and when you are trying to rev out, the pistons cannot compress water.

Take out the plugs and dry them off, or just ride it out, it will go away eventually as the engine heats it, the water will evaporate.

 

Huh? I guess he must have taken his spark plugs off as well to get water into the cylinder?
I guess it's possible to get water in the plug tubes... which would cause a direct short from plug to ground - complete cylinder misfire.


Anyway, thinking you might have gotten water into a connetor someplace.
Pop open connectors and hose them out with WINDEX, shake them out, and let it dry a minute before putting them back together.

Could be water in your spark plug wires as well. With your engine running, use something insulated (so you don't shock yourself) to remove spark plug wires one by one and see if your idle changes. If it changes, hook it back up and move to the next one. If there is no change then you have a problem with that wire/spark plug/cylinder.

 

700-800 is fine idle for my car (per the OEM specifications).

Idle is controlled (certain vehicles may me excluded i'm sure) by many items and sensors. Some of them being...

FICV
The fast idle control valve (cold start control valve...the valve mounted beneath honda throttles) has a temperature dependent thermowax inside that expands(?) when heated up in turn closing the air port. This is used to raise the idle in winter or cold-starting conditions. Coolant is ran through this valve in order to warm it up with the vehicle and lower the idle.

IACV
The idle air control valve (mounted on the firewall side of your intake manifold) controls and stabilizes the running conditions producing the hysteresis, or gray band of your engine air intake under idle (and constant velocity driving) applications. This valve also is altered by a thermowax substance to shift it due to temperature variations.

Throttle
Idle screw located on the throttle. Screw it outward, idle rises and vise versa. This simply opens and closes a mechanical port allowing air to flow accordingly.

TPS
The throttle position sensor ( on the side of the throttle) inadvertently changes the idle in a couple ways. If the TPS is unplugged (or loss of signal), the ecu will not know exactly where the throttle is. Because the ecu doesn't know, there is a 'just in case' routine written in order to raise the running idle (by shifting the IACV values) thereby eliminating possible closed throttle killing of the vehicle due to starvation.

there are others, but my post is already getting longer than intended.

If the idle is dropping too low (such as in cold start conditions and the sort may attribute) then what could possibly be done to bypass the scenario temporarily is to unplug the TPS. Be warned, the ecu will likely go into 'open loop' (or closed look, cant remember which) mode thereby running your internal fuel maps instead of relying on a lot of miscellaneous sensors (it will ignore a lot of stuff). Try unplugging it and see what happens.

WE NEED MORE INFO ON VEHICLE SPEC

comments, questions, corrections welcome

 

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