99 Accord 4 cyl idles way too fast, need help quickly!!

[chubbygoatboy]

To make a long story short as possible, here it goes: 1999 Accord Vtec engine, 254k miles... Has new plugs, wires, cap and rotor, they were bad. Ran great for a couple of months after the tune up. Then started dying sometimes with a low idle after it got warmed up like when you would stop for a traffic light

It had a bunch of codes, most pertaining to the EGR, so I pulled the EGR valve and cleaned it the best I could, then found the passage from it into the upper plenum was jammed packed full of carbon and oil, so I then pulled the upper half of the plenum and dug out the passage and now have it 100% open and clean. Also cleaned the air temp sensor tip in the plenum, cleaned the throttlebody etc. Also noticed there was a lot of oil in the lower half of the plenum, and found the PCV valve stuck open, so cleaned it as well.

Put it all back together and found that it now wanted to go too low at idle when cold?? Checked all vacuum lines I had off to make sure I had not missed one. Did not find any. Then, it changed to a high fast idle all by itself??

Cleaned the MAP sensor passage and installed new MAP sensor. No change, still revs way too high at idle, like 2200rpm. What am I missing? None of the codes have come back, and it drives down the road just fine without dying. But cold or hot, the idle is just way too fast. I need to fix this quickly!!

ANY ideas are greatly appreciated! BUT, if your uncle had a 32 Buick, that had some strange issues, it won't really help me out with this one. Not trying to be a jerk here, but I love this forum, and quite frequently I see replies that have absolutely no value to the questions asked !!

SO, thanks in advance for your valuable, pertinent, responses!! THANKS again!!

[jeffcoslacker]

Some debris from the cleaning got the IACV sticking?

[chubbygoatboy]

THANKS, I will pull it off in the morning and see if it has something in it. There was enough crap that I cleaned out of everywhere else that it is entirely possible. Any other ideas are greatly appreciated, and I will follow up with my findings! THANKS

[somick]

Thank god my uncle did not have a 32 Buick... (:-|

And on a serious note. Check for debris what jeff recommended.

And a phrase that I remember from one of the manuals (either Haynes or other...): if rpms are out of specs, check your ECU. In other words the computer is responsible for your rpms. The best way would be to swap it with a known good one and see it anything changes.]

I hope this helps,

Sam

[chubbygoatboy]

I did take off the IAC and cleaned it. It definitely was carboned up some and needed cleaned. But, it did not fix it... BUT, then I remembered that I had tried to bend the throttle cam tab where the throttle cable hooks on, just to see if I could make it idle faster by basically changing the position of the rest position. So I pried gently and carefully with a screwdriver. I did not think that I bent it any, as it was pretty stiff, so I kind of forgot that I did that. Well, on a hunch, I took a pair of channel locks and squeezed it back together some. With the pliers, it actually bent pretty easy. THAT fixed it! DUH, boy do I feel stupid.... Now it idles perfect... I know that the EGR port was surely an issue, and the MAP was as well, and the IAC also, but then I was at a loss as to why it still was not quite right!! THANKS for the input!