M.A.R.C.

OK... I have a problem. First the info...

2000 Civic EX 5 speed...
the mods really aren't relevant since the problem was kinda apparent when the car was put back to stock.

Problem: Vacuum leak-type idle (varies in intensity) , IACV CEL.

OK. After I ran nitrous on the motor about a year+ ago I took my car to the dealer (after I sold the nitrous) to check out this weird idle I had been having. The idle would stick at 2000 rpm when I stopped the car after driving, then after a while it would settle to normal. They told me my throttle plate was bent and was responisible for the fluctuating idle. ***Time passes***. IACV check engine light would come on occasionally and send the idle to hell. Turn the car off then back on, the WORSE idle would go away. ***Time passes*** Fast forward to present day. Car is turbocharged now. Still the same problems as before... but it's more annoying now and occurs more often. So I took it upon myself to get a used throttle body and try to swap that on. Upon checking the throttlebodies against each other I realized that they were different. The used one had the


Left: used 97 one
Right: Stock one


I was told the one I bought was off a 97 D16Y8. Anyway I didn't have the gasket for the 97 so I decided to swap just the plates. Well doing so resulted in a huge vacuum leak-type idle. I checked other places for leaks didn't find any. So I tried swapping the plates to the corresponding throttlebodies. The idle is a little bit better, but the IACV CEL comes on MUCH MORE often. In a 1mile trip... every stop I was at for more than like 45seconds resulted in the IACV CEL going off. My next test will be to get the 97 gasket and try putting the 97 TB on and hoping it works. Other than that, I'm going to try to look for a 99-00 TB, the 99-00 gasket, and use a lil hondabond on the gasket (is this OK?) to make sure it seals and that's not my problem. Anyone have any insight or help or suggestions to add to this? Funny thing is, I did a throttlebody swap on my friend's 98 EX auto, and it worked fine and fixed his problem, yet I can't get mine to work


[Modified by CivicRyda2k, 10:22 PM 2/16/2003]

Evs-One

why don't you replace your IAC? With the exhaust gasses coming back through the intake piping, your IAC screen will get dirtier faster. I would pop it off, clean off the screen, spray it out with carb cleaner and be good.

M.A.R.C.

well as the car is setup now... the crankcase breather isn't routed to the intake pipe. you reminded me however that cleaning that could help. I'll try that and see how it works but I doubt that will help get rid of the problem completely.

Evs-One

if the CEL comes on only once in awhile, clean it asap. If it stays on, you're looking at a couple hundred from dealer, unless you find one used.

So, did you get the TB sealing problem fixed then?

M.A.R.C.

Yah I'm gonna clean it tomorrow. I dunno if it's sealing correctly or not but I'm guessing that may be it. Because all I did was swap the throttle plates from the used throttlebody to my stock one which resulted in worse idle, then i swapped them back to normal, and now the idle is not so bad but the IACV came on like almost every stop. Can those things like burn out or something? it could be that THAT's what is actually bad and NOT the TB.

M.A.R.C.

Someone correct me if I'm wrong but I think what this person sold me wasn't a 97 EX Civic 5spd throttle body but infact a CRV/Integra automatic throttlebody.

Here a few pics of it

intake side view, FIT valve at the bottom. My Haynes manual says the FIT valve was only on CR-V/Integras with auto trannies.


this is the stock gasket for my throttlebody comparing it to the surface of the used TB


This is an automatic TB gasket for a civic I had lying around from when I did a TB swap on my friend's auto civic. Not sure for what year.



can anyone veryify if this is actually a obd2 civic throttlebody?

M.A.R.C.

up...

Evs-One

I doubt it's the throttle body. I've never seen one warp, but that's just me.

My room mates turbo setup ruined his IAC after a year. It was gone for good, so we had to replace it. If you clean it out and reset the ecu before it knows it's bad, then you should be good. Clean it out and see what happens. That wil be the easiest thing to do. run your original TB also

M.A.R.C.

ok... pulled the TB used some RTV to help seal it. Pulled the IAC... cleaned it... but the plunger looked kinda bent. Last time I pulled it, it didn't look like that. Gonna try a different IAC (if I can find one), and hope to God that works.

TTT!!!!!!!