Does your Honda Prelude engine run rough, like a valve got
sucked up or it's only running on 3 cylinders?
It might have a vacuum hose that is cracked and leaking,
sucking excessive air into the system, making the engine run very bad.
Honda will charge you $150-$200 to fix this but you can do it for $2 in 10 minutes!
There are two 2" vertical hoses about 12 inches apart on the top of the engine.
They get very hot and crack about every 100,000 miles,
these could be causing your problem. See photo (red outlines):
Drive to an auto parts store, bringing a Phillips screwdriver and pliers.
CAUTION- ENGINE WILL BE WARM OR HOT.
Remove the screw (blue outline) that hold this vacuum bar down.
With pliers remove the clamps off both vacuum hoses (red outlines)
and pull out the 2 hoses.
Do they look cracked and worn? They might even have invisible cracks.
Walk into the parts store and let them know you need a foot of this size vacuum hose.
While you are there, have them cut pieces the same size of the hoses you brought in.
Save the extra pieces for the next time and you can do this when the engine is cold.
Now go to your Prelude and install the new hoses.
Start it up and hopefully she'll be purring like a kitten again.
Did this solve your problem? Most likely the hoses needed to be replaced anyway.
By the way, the photo above is of my engine that has 340,000 miles
on it as of Jan. 2001. I bought the car brand new in 1984 at the
Simi Honda dealer and the car's reliability amazes me.
How the Prelude "Auto" choke works
Turn the ignition on (don't start it) until the idiot lights come on,
gently press and release the gas pedal (this sets the auto choke),
now start the engine WITHOUT giving gas.
Your engine should now start at a good rpm without stalling.
Check out Honda Auto Parts Wholesale for parts.