My 1990 Accord DX is idling up and down.... I've tried replacing the throttle body.. I've checked for ECU code and all I'm getting is the CEL staying lit ( not flashing any codes ) This is the stock engine with 145,000 miles on it.. What could it be? Thanks for any help...

 

anyone??

 

If your antifreeze isn't low and there is no air in the cooling system, i'd look at the fast idle valve.

 

you said the idle moves, does it dip low then back up to normal or does it go high then drop down to normal?

sometimes mine dips low then comes back up a couple times until i give it gas then it stops acting up...don't know why it does it so maybe yours is the same?
also, did you jumper the blue connector to read the ecu code?

 

It idles at about 1000 then it will jump up to about 2000-2500 then drop back to 1000...Then just keep repeating itself. It doesnt matter if it warm or cold. I jumped the terminal to check the ECU with a paper clip.. CEL is not flashing a code.. Have'nt checked for air in the cooling system yet, hopefully get to it tommow...

 

there is various reason why ure car is giving that problem.. 1 main relay going out.. then ure fuel pump maybe going out.. or ure distrubuter is not cranking enough sparks.. not the component inside the distrubuter but the whole distrubuter it self.. soo many reasons.. so u better just send it to honda dealer ship for a check.. ask them to find out wat is wrong wit it.. then fix it ureself.. it shouldnt cost more than 80.. hope that helps..i have a 91 accord.. and i have basiclly change every single component that i have on that car.. the engine is basiclly new.. soo.. those are pretty much wat would cause u that problem.. hope that help.. thanks

 

I have a 1990 honda accord lx and no matter the weather when i first start it,the idle revs from about 1200rpm to about 2000rpm,after like 10 minutes of running it stops.