Help! Super Extreme High Idle!5000rpms!!

[hondas_only]

Allright,first of all I have a 1989 civic dx with a 95 D16z6.I just swapped in a 2000 civic EX intake manifold and now my car High Idles at 5000 rpms cold and then bounces from 1,500 to 3000 when warm.I thought it might be the intake manifold gasket so I changed that again,nothing.Maybe it was the IACV,changed it,nothing again,runs the same.Then maybe it might be the PCV,changed it,runs the same.I used the same throttle body from my 95 in this,so I know its not that.I even checked the manifold for cracks,leaky vaccum lines,bled the cooling system,double ,tripple checked everything.The only thing that is wrong that I can find it a moist fuel injector(cus I smashed the 1991 injector gasket)caused from having the wrong injector gasket,but no leak just gets moist.I search this entire forum for the same problem,found high idles,but nothing compares.Any help would at all even ideas would be awsome.I'v been driving Hondas since before I turned 16 and fixing and improving them for over 5 years now so I'm no nooblet,just stumpped.

[FrodoGT]

Dude that injector seal is a major vacuum leak.

[Tony]

Vacuum leak is probably causing the fluctuation. The High RPMs just sound like you need to adjust the idle down some, either at the bracket, or there is a flat head screw on the top left corner of the throttle body you can use to adjust it too(might do a little more, hell if I research things before I adjust things..big believer of trail and error)

[hondas_only]

I put a lit cigarette next to it and it was suckin in the smoke.Got new ones ordered for the 96-00 ex.I'll post an update.Thanks

[hondas_only]

The throttle body worked perfect on the 95 manifold,idling at 800rpms warm.Could it possably change idle by bolting it to a different manifold,but it bounces at 1500 to 3000 like the IACV is screwed up in high idle.I bolted on my old IACV and it did the same thing.I'm all about trial and error too,thats why I dumped $500 into a $10 job,but I end up with alot of new parts and less problems down the road.After I put the parts on I'll post the results.Thanks for everything told me and anything to can tell me,i'm sure 90% of the people on here know what its like not having a car for stupid resons.

[FrodoGT]

well you did reseal the TB after putting it on a new one right?

[Tony]

The idle will change if you removed the throttle cable from the intake manifold, you won't always get it back in the same spot everytime.
Like I said, sounds like the fluctuation is coming from your vacuum leak and the high rpms is just your idle set too high. Normally they will idle high when they are cold and then drop when they are warmed up.

[hondas_only]

FOR SURE! All Honda gaskets all the way around.Here let me type this one again,When I start it up,it goes straight to 5000,then it will warm up REAL quick and drop to 4000.Then it will drop to 1500 then rise to 3000 and bounce like that forever.I can drive it but to be normal I have to cruise above 3000 wich is around 64-65mph(1991 CRX DX tranny).I took it out and went through the gears,it has power just a funked up idle.The throttle cable I messed with for awhile getting it right,I have a 95 Si throttle cable on it(wich don't work for shit but I figured it out).I was hopin to get this sucker going for the 1/8mile drags at the Lacrosse speedway this year,but looks like its going back to stock if nothing works(its still goin to the drags no matter what).I have a digital video camera,and if someone tells me how to post video with sound I will be glad to do that.I will be checking this site 50times a day and it will be posted as quick as possable.Thanks again!-The video camera I have plays .MOV format and plays on QuickTime player.

[FrodoGT]

Take the throttle cable OFF the wheel for starters..just to see.

[hondas_only]

The first time I started it I didn't have the cable on it anyway,so that can't be the problem.It has to have a vaccum leak.Everything I'v read about the 6G intake manifold swap said used 5G manifold gasket and make sure to get the 5speed manifold so you can interchange all the parts from the old manifold(AT manifold has IACV on TB),basicly plug and play.I have a foot 1/2 long vaccum line going to the purge sensor,I checked it for leaks but I don't trust it nomore.Its on time,its had a complete tune up,AEM highflow rail,AEM Regulator set for 47psi(stock psi),new O2 sensor,and brand new injectors(91 SI).The car has a full 91 Si harness front to back running the ZC computer,so no wiring issues beside intake temp wire that needed extra wire,V-tech is also hooked to a switch on the shift knob.The car throws 0 codes,but that don't all way mean anything.Thats about the whole car in a nutshell.Where is the most odd place for a vaccum leak to hide?,thats probaly the answer.

[hondas_only]

I figured it out,the intake manifold must be warped or the newer 6G manifold guessing 98-99-00 it either doesn't match up right OR mine is shot.There is probaly a 2/32 of an inch gap between the manifold and the head a couple inches down the top of the manifold starting on the distributor side.Does anyone got a 96-97 civic EX 5speed intake manifold completely bare forsale?I'll buy it for a resonable price.Thanks again for your help.I'm just glad someone responed to me,and I'm gonna be sticking around to try to help people.

[hondas_only]

WRONG! the Y8 manifold has air breather holes for each injector that DOES NOT seal,so its sucking in the air like crazy.Why is it that no-one says anything about it in any of the swap guides I found online?Problem Solved.