I buddy of mine has a 87 honda prelude (not rice, completly stock beater)
when you turn the car on it will jump to about 3000 RPM and stay there for a while, after the car warms up some, it will start to idle realy bad where it will rach around 2500 RPM and drop to 700 RPM or so and do this constantly, kinda like its having a asmha attack or something, We changed the spark plugs, wires, fuel filter and brake booster and it fixed it for a while but its doing it again, i was personaly thinking it might be the fuel pump because when you touch the fuel filter while its doing this you can kind of feel the fuel rushing through it ans slowing down.. then again it could be something else.
the car has about 240,000 miles on it. he also said the his gas milage droped and it lost a little power. could the 02 sensors have anything to do with it? he also over filled the anitfreeze resovoir big time, would that effect it? lastly he says it will sometimes over heat. any help is greatly appriciated

 

You're probably not going to get much help in this section. Try posting this in the Lounge.

 

im not sure how similar it is to my 93 honda accord but...i had a similar problem with mine. turns out it was the eic valve. yours might be out of adjustment or it might need replacing. also the throttle could be adjusted too tight.

however i have been told that it is common for the cooling system to cause this problem if it hasnt been well maintained. there are two hoses that go in around the eic valve. if the system is poorly maintained it can clog thus the idle will be out of wack. to test and see if it is flowing let the car warm up and feel those hoses to see if they are getting warm. if they dont you are in for some fun cleaning. luckily my car did not have this problem.


if it is carbed then i am not sure

 

the tempature was up a little more than half way and the 2 main radiator hoses (the ones that connect to the radioator) where cold and dry as a bone, the radiotar itself seemd empty aswell, i took off the cap and barrly any thing was there, Is the EIC valve the component in which the top radiator hose is connected to? what does EIC stand for? thanks

 

electronic idle control valve...assuming it is fuel injected it should be near the throttle linkage...that is where it is on my car anyway. the hoses are about the diameter of a dime...they are not the fat ones.


if it has dried up like you said i am thinking that might be your problem

 

I know you are searching for a fix, but posting Honda questions here is a bad precedent. The moderators have enough to do, eh?

 

yea i know i would ask the honda guys but they dont know **** about cars, theyd probly tell me i need a spoiler or stickers or something to fix the problem

i also warned people that this wasnt for an lt1 so if people didnt want to read it they could avoid it. sorry if i pissed anyone off. im just trying to fix something that hopefully other people can benifit from not for just being a honda but for cars in general.

 

That is what i am thinking. I got help everytime i needed it there about two different car, and they werent GM.

I would really like to help you but you posted in the LT1 section man

My guess is fuel pump, that eic thing (240K miles, who knows if it has ever been replaced), or a vac. leak (not too likely with your symptoms though, since you said it went away). Stay away from the dealer as long as you can, they charged my freind $470 to change pads and spark plugs!