Honda Repair: RPM problem on my 1990 Honda Accord LX, vacuum hoses, salvage yard

Question
Hi,

I have a 1990 Honda Accord LX.  When the engine is cold the RPM goes up and down (approx. from 75rpm to 3000rpm)continuously and I have to leave the engine running for at least 15min then it stabilizes until it reaches a certain temperature.   My mechanic already changed the idle control valve and the throttle sensor but the problem still persists.

I haven't gone to the Honda dealership for service. Approximately how much would it cost to fix this problem?

Thank you for your prompt response.

Regards,
Gerry

Answer
usually when you replace the idle control valve and the throttle body sensor it doesnt help becuase it is just calculating what the old ones did. you need to replace the whole throttle body. these are cheap at local salvage yards. you can use one from ANY honda years 90+ accord, 92+ civic, 92+ prelude, 90+acura integra as long as it is 4 cylinder.
if he did not calibrate the sensors it does no good to replace them. the whole tb needs to be replaced or they need to be calibrated. you could do it by yourself in less than 5 minutes. i would get one from ebay or a salvage yard. *note8 if you get a larger one like 73mm and up it will increase your horsepower and you will get better gas mileage*

here are the steps to replacing it.

release the black hose connected to the throttle body(pictures below) using a pair of pliers to pinch the clamp holding it on.

after sliding it off, unhook the clear/yellow/orgray plugs that are connected to the throttle body.

use pliers to pinch the clamps holding all the vacuum hoses and slide them off the TB.

use some pliers to unhook the throttle cable from the front of the coil on the TB.

use a 12mm socket to unbolt the TB. there will be 4. one on each corner. actually depending on the car it could ba 12 or 14mm.

it is reverse for installation of the new one.


any throttle body off any car 90+ will work as long as it is fuel injected. it would not be cost efficient to take it to a dealer. you can do it yourself. you can get it calibrated but it is really a waste of money and time. these are cheap (under $50) on ebay.

here are some pictures:


accord Throttle body:
http://www.superhonda.com/photopost/data/513/3435throttle1.jpg
A- coolant hose 1
B- coolant hose 2
C- Clamp

you will see the plug on the back side of the throttle body.

here is a good place to get one;
http://motors.search.ebay.com/accord_Throttle-Body_W0QQcatrefZC6QQcoactionZcompa...