Hi, My Mother gave Me her 1998 Honda Accord Ex Manual Transmission with 214000 miles on it. She said it ran great 3 years back when she was last driving it, She got very sick and stopped driving so it sat for 3 years. I replaced the engine oil and put gas in the tank and it started up no problem reving at a constant 2000RPM I tapped the gas pedal and it revd up to 2500 back to 2000 over and over non stop. I removed and deep cleaned intake manifold and all that was attached to it as well as replaced pcv valve and car now idles at 1000RPM but once I tap the gas just the slightest it goes back to fluctuations this time now at 1000RPM TO 1500RPM up and down constantly. What might be the issue?
The vacuum hose for the pcv valve most likely rotted
If that's not it check the other vacuum lines. Btw what engine is in it
4 cylinder manual vtech engine...not sure if that answer is 100% but that's pretty much all I know at the moment...The problem was a throttle control valve/sensor though but now I have a coolant leak. Disassembled put paste tube gasket stuff and I'll try again tomorrow... thanks for your help...
Maybe needs a new IAC valve. Available from Rock Auto, Parts Geek and everywhere else.
You were absolutely right thanks alot I appreciate you...
Way to go doc ....
I've figured out the issue after hours of wrenching on things...Its was the idle control sensor or valve part directly next to intake ... A part that has a little small motor for opening and closing off intake air/fuel it was gunked up and wouldn't close fully...Cleaned it very very good and now I can tap pedal all I want and no continuous reving... after replacing the part I'm guessing the little gasket wasn't good enough because now coolant gets in the exhaust and check engine light is now on. Went to buy new rubber gasket but it's not sold separately so I'm going to give the paste in a tube gasket stuff a try along with old gasket because old gasket wasn't damaged maybe just shrunk to the point it didn't seal good enough so hopefully it'll seal properly and my problem will be completely fixed. Thanks everyone for the help...