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Discussion Starter #1
I recently bought a 5spd 5th gen with low miles, but it sat a while and I think the intake is dirty. When i start the car up cold the idle surges up and down for 5 min until it is warmed up, then levels out at 9oo rpm. My mechanic said it was the throttle body manifold, he adjusted the idle screw and it seemed to get a little better. He told me to take throttle off and clean it, so i did soaking it in purple power overnight, after i reinstalled the idle was surging like it was before, but this time the idle surges sporadically even when it is warmed up. and the car jerks when i give it gas/take my foot off the pedal.I think there is a map sensor or something along those lines bad... any advice/critism is welcome thanks! PS I checked vacuum lines they apear to be solid as far as i can tell so far
 

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http://honda-tech.com/honda-prelude-4/end-all-idle-surge-bounce-etc-problems-thread-1979500/

Honda idle systems seem to be pretty picky (something as simple as someone messing with the idle screw can cause this issue... if it is surging like that when its cold it could mean the have the screw too far open. 900 once warmed up seems somewhat high, I think it should be around 700), there are several other things that can cause idle problems as well... check that thread out, your problem is probably in there.
 

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Discussion Starter #6
http://honda-tech.com/honda-prelude-4/end-all-idle-surge-bounce-etc-problems-thread-1979500/

Honda idle systems seem to be pretty picky (something as simple as someone messing with the idle screw can cause this issue... if it is surging like that when its cold it could mean the have the screw too far open. 900 once warmed up seems somewhat high, I think it should be around 700), there are several other things that can cause idle problems as well... check that thread out, your problem is probably in there.
I suspect its the fast idle screw, i had an Integra b4 that had that problem
 

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I suspect its the fast idle screw, i had an Integra b4 that had that problem
Yeah that screw is supposed to be the last thing to be touched when all else fails, if it looks like the resin they put over it from the factory has been removed, then maybe someone messed with it before. If it is very far open you can hear it whistling on the throttle body if you listen closely.
 

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Wait. You soaked the throttle body? I'm guessing you left the tps (throttle position sensor) on since it's riveted?

So about this?

, he adjusted the idle screw and it seemed to get a little better. He told me to take throttle off and clean it, so i did soaking it in purple power overnight, after i reinstalled the idle was surging like it was before, but this time the idle surges sporadically even when it is warmed up. and the car jerks when i give it gas/take my foot off the pedal.I think there is a map sensor or something along those lines bad... any advice/critism is welcome thanks! PS I checked vacuum lines they apear to be solid as far as i can tell so far
New gaskets?
 

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Discussion Starter #10
Sounds like the FITV (Fast Idle Thermo Valve) which is attached to the bottom of the throttle body. Here's a link on how to clean it:

http://honda-tech.com/acura-integra...your-fitv-aka-fast-idle-thermo-valve-1564019/

Or, you can simply just spray the inside with some throttle body cleaner without full disassembly, screw the plastic part all the way down, and then back it out "1-1/2 to 3 turns".
I did this already on mine, its actually 2 10mm bolts on a '98, and while i didn't completly screw the plastic screw out and clean it, it was loose and i screwed it down all the way and put it back on, this didn't fix it unfortunatly:(
 

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Discussion Starter #11
So about this?



New gaskets?
I put a new gasket on the throttle body, didn't replace the rubber rings though they still looked good. and yes i soaked the TPS, that doesnt seemed to have changed at all though. I tried adjusting the idle screw a little but did't change anything. Now when i put the car in nuetral(its 5spd) it idles itself up to 2000rpm until i come to a complete stop, then it settles at 1000rpm
 

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1000 when settled is quite high, have you got the idle screw all the way tight? The only way I can make mine idle that high is to basically have the idle screw backed off all the way loose from the throttle body. Has the throttle stop been messed with and maybe its not allowing the butterfly to close all the way?

Also have you tried spraying the whole area with some carb cleaner to try and detect a possible vacuum leak? If you spray a spot and noticed your idle surges briefly then you may have a leak in the area that was sprayed.
 

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Wouldn't surprise me if you killed the tps soaking it.

Start about 11min into this or watch the whole thing but 11 in gets to a test you can do.

Nevermind I see you did the FITV.

Maybe grab a fire extinguisher and some propane or carb clean and spray around the intake gasket.
 

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Discussion Starter #14
Wouldn't surprise me if you killed the tps soaking it.

Start about 11min into this or watch the whole thing but 11 in gets to a test you can do.
www.youtube.com/watch?v=hB44oejFsL4

Nevermind I see you did the FITV.

Maybe grab a fire extinguisher and some propane or carb clean and spray around the intake gasket.
I replaced all the hose lines and screwed the fast idle valve down all the way.... the surging stopped totally but now when i put the carin neutral as i slow down it idles up to 2500-3000 rpm. as soon as i come to a dead stop, it goes to 900rpm. So i dunno what it is still looking for a solution
 

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I replaced all the hose lines and screwed the fast idle valve down all the way.... the surging stopped totally but now when i put the carin neutral as i slow down it idles up to 2500-3000 rpm. as soon as i come to a dead stop, it goes to 900rpm. So i dunno what it is still looking for a solution
Maybe Idle Air Control Valve is going out
 

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Discussion Starter #18
Jtec- is it real??

After being told how bad my rings are resulting in excessive oil burning, I decided a newer engine swap is better than a re-build. I've heard rumors of a "Jtec", supposedly a Vtec that comes from Japan and has like 50 more HP stock or something. I cant find anything backing this up, can anyone tell me if it's real or a rumor people brag about having. I met a guy years ago who swore he had one in his integra, 1.8L that he bought off the boat from Japan for $7,000 with 50,000 mi on it.:upside:
 

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Content deleted, because, some little snowflake out there can't handle some garage talk. That, and wing9903 says they are too long to read.

 

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Discussion Starter #20
I have never heard anyone brag of anything like this in over a decade of owning Preludes.

There are JDM engines that can be swapped in that have more horsepower, but none approaching anything close to 50 horsepower more than USDM, and none called "jtec".

Type-S H22A 220HP + ATTS. (red valve cover) Swaps into the USDM Type SH
S-Spec H22A 220HP comes with an LSD transmission, or can be used without. (red valve cover) Best fit for a USDM base model.
Accord Type R (ATR/Euro-R) H22A7 210 HP (red valve cover) Best fit for for a USDM base model.
What does JDM stand for?
 
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