94 Civic Eratic Idle Problem - Have read all posts still no luck!

Hi all. This is my first post to the group I hope I'm able to get help.

I have a 94 Honda Civic D16Z6 1.6L V-Tech. It overheated and warped the
head. I replaced all gaskets mill had the head milled flat and pressure
tested. Replace a busted throttle body (it was broken during removal).
And all attached sensors. Removed and check IAC Valve. Engine sounds
good, sounds great actually. No pinging or valve ticks. However the car
idle eratically after being on for only minutes. Pressing on the gas
causes the engine to hold a steady rpm above 1600. The pedal to engine
response is good which makes me think this is not a timing issue. I
have no idea how to check the timing. I have a Chiltons manual but
could find nothing listed. What could cause this other than known
sensor issues TPS, IACV, FITV, no codes to display, the engine light
never comes on. Engine does not overheat. Just a very very eratic idle,
1000 - 1600 rpm. I'm tired of everyone thinking I want to race them at
red lights. Can anyone think of any other known issues?

Help is GREATLY Appreciated!!!!

 

Did you thoroughly purge the cooling system of air? Is the
cooling system topped off?

Starting from cold engine, this will require idling the car
for 40 minutes or so to get the fan to come on twice.

Air in the cooling system will result in inadequate
temperatures of certain engine control components,
potentially throwing off the idle.

My Chilton's manual covers the 94 Civic. "Checking and
Adjusting the Timing" is in Section 2, under "Ignition
Timing."

 

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Try filling the coolant reservoir to the MAX, three mornings in a row
(while the engine is stone cold). If the level is dropping each morning,
you're still expelling trapped air. Don't forget to run your heater on
HOT so the air can escape from the heater core too.

'Curly'

 

Doesn't the 94 Civic have a coolant air-bleed port like my 94 Integra B18
engine?

 

I have cleaned the cooling system 3 times now flushing it out one of
those times. Topping it off each time and letting it idle with the heat
full blast.

I have a new symptom now.

When I start the car it immediately starts hissing. I am positive this
is due to a vacuum leak somewhere but I cannot pin point exactly where
it is comming from. The car is able to run and drives great, however
after running the car for say at least 15 minutes when you turn it off
some coolant will spill out. I assuming its from the same place that is
hissing. It seems to be under the intake manifold somewhere however I
cannot see down in there far enough to find the leak.

Anybody know of any commong vacuum leaks or hosing that came come
undone easily?

Thanks.

Tek

 

Air leak. Check Fast Idle Valve under throttle body.

With engine full-warm and running, remove air pipe from cleaner to throttle
body. Immediately in front of the throttle plate, there are two ports in
the throttle body. Is there suction at the LOWER port in the throttle body?
If so, Fast Idle Valve is stuck.

 

I read that on another post somewhere and checked it. When I checked it
it wasn't all the way warmed up I don't think but it had suction. I
know this isn't the problem however this part was just recently
replaced from another civic I have. The other civic was in perfect
running order. Also I know this would not cause the whistling noise I
am hearing along with the stuttering that occurs frequently when
pressing on the gas in gear.

Any other ideas? Good gueses so far however I have already tried all
these avenues.


Tek

 

You have an air leak somewhere. Follow the whistling noise. It is obviously
giving you a clue here.

 

LOL I know that it is giving me a clue I could not find the whistling
noise..... I also know why I couldn't find it. I had already found it,
I thought it was under the intake manifold in a hose I couldn't get to.


It was the intake manifold itself.... well the gasket anyway. I
replaced it and it purrs like a kitten! Wow this car has been sitting
for two years because of two problems, throttle body and the attached
map sensor and a messed up intake manifold gasket.

God it feels good to have my trusty civic back!

Thanks to everyone for their help. I learned a hell of a lot of things
about my car just trying to figure out these problems. I want to thank
the internet gods, my grandpa for getting me into computers, and also
all the honda people out there for sharing their secrets with the user
group community!

Tek