once car is at operating temp it will idle between 1k and 2k. starts at 1, jumps to 2 then back down to 1. goes back and forth like this as if im reving motor and letting it down.
heres what ive done:
replace all vacume lines in car.
replaced all coolant lines in car (eh got bored)
replaced egr valve
replace evap
replaced o2 sensor.
readjusted idle screw 2789046589046159078134 times
inspected and cleaned tbody

ecu thorws no codes at all. when i turn car off it will blink 1 time then power is gone so who know how many blinks that really is.

this happened after i replaced tbody and trans. tbody worked fine on other motor. my old tbody has a fuct tps hence the tbody swap. this **** sucks please help

what i havent done:
cleaned injectors
swaped ecus
checked all the mpfi wiring (would mostlikley throw a code if that were the case, plus all those connections are next to impossible to break)
im stumped


[Modified by TorteX, 7:22 PM 6/2/2002]

 

If this happened after you replaced the throttle body why didnt you swap back and see if that fixed the problem. I would guess that either you're using the wrong throttle body gasket or you have a vacuum leak at the gasket.

 

i did that, didnt go away. new tbody doesnt have any where near the miles my old one has. inspected tbody all looks good

 

a leaky head gasket could cause that too

 

id would prolly be pissing oil and collant everywhere tho. id see it in the exhaust as well, everything checks out tho.

 

if it was a vacume leak in the lines id think it would do it all the time no? only does it after car is warmed up. hmmm

 

doooood i am having the same exact problem car runs fine but when warm rpms go up and down up and down it pisses me off did u fix it yet man cause i would like to know whats wrong with mine lol

 

try cleaning the pcv valve

 

how do i do that

 

I have the exact same problem... done pretty much everything TorteX has done... GRRR

 

My car did this when I used to run 88 octane and when the motor got really warmed up. Now I use 89 octane and everything is fixed.

 

see the three vacum hoses on the manifold? the middle one leads to the pcv valve. it a plastic peice with a 90 bent it extends through the manifold and goes into this object i dont know what but just pop it out and clean it. i used carb cleaner cuz i was cleaning my eavc also, but not sure if i should have, being its plastic and all. but i didnt let the carb cleaner do any harm. theres a little valve in there that should be loose; shake it and if it rattles its still good if not replace it....this is what i read from a post on this site...hope it helps...

 

Mine does the same thing.. But only when its cold.
Whats weird about it is there is a little hole inside the TB about the size of the end of a pen.
If I plug it with my finger the idle smooths out..

I dunno.. I was going to replace the IACV whenever I get the chance to get off my ***.

 

i don't know if its the same on d-series motors, but I had the same exact problem on my b16. It was the fast idle valve underneath the throttle body (do d-series have a fast idle valve). Check out this thread.

https://honda-tech.com/zerothread?id=263291

Hope this helps

 

I replaced my tps sensor . Weird idle like that seems to be a nightmare to get rid of. On the bright side of things, all of the crx's I have owned that did that, ran good as hell! Maybe your not driving it right!

 

I was on your position before. I replace everything like you did including the injectors Throtle body and the EAVC valve. More likely the case on some people the replacing EAVC vlave would do the Job, But mine didn't. I have to see a honda mechanic to figure it out, cause 2 mechanics had failed. Mine was the Intake manifold gasket! I don't know how, but If you search an archive since last year, we had a long discussion of ideas and plenty of help to solve my problem. goodluck

 

Anyone try bleeding your coolant yet? And then try cleaning the IACV. HTH

 

because the MAP Sensor (manafold absolute pressure) reads the air in the manifold an figures how much air to dump or not. If you can hear it kick on & the vacuum is good, it must be somewhere else in the manifold (aka gasket)

 

ya im surprised this thead came back. only thing ive done since june when i posted was check for more vacume leaks. there are none. basicly dumped buckets of carb cleaner on motor =P no leaks. prolly the evac

 

Thanks for the help Red Civic Standard... Where is the fast idle valve on my B16? Its directly under the TB? What does it look like?