Cold idle speed high, warm idle speed normal...

[mhuffman]

When i start the car up after it has cooled down for a few hours, it idles between 2000-2500rpm's. Once it has warmed up, it idles around 1000 (which is still a little high). Is this high cold idle speed normal?

 

[silvawolfe]

Is this high cold idle speed normal?

It really depends on your definition of normal...Normal intended operation...No, Normal problem for a DSM..yes.

There have been hundreds of posts on the subject and the major culprit has been the little pellet inside the fast idle valve attached to the bottom of the throttle body had ceased to do it's job. You either need to repair/replace it or block it off.

 

[mhuffman]

It really depends on your definition of normal...Normal intended operation...No, Normal problem for a DSM..yes.

There have been hundreds of posts on the subject and the major culprit has been the little pellet inside the fast idle valve attached to the bottom of the throttle body had ceased to do it's job. You either need to repair/replace it or block it off.

Thanks for the reply, i'll go investigate it and report if the problem is better.

 

[95 'clipse RS]

i have some sort of idle problem too think. well see it idles about 1300rpm when the lights and heater are off, and when they are turned on it drops to about 800rpm. could this be the same problem, or do you think its some kind of electrical problem? like a bad ground? also does the 4g63 N/t have this same fast idle valve on the TB? also the Idle adjustment screw is all the way in and its still idling about 1300rpm. any help is appreciated thanks.

 

[Kloopofadown]

95 'clipse RS, your Idle Speed Control motor could be dead or unplugged. Yes our N/Ts have the same fast idle valve. Do a boost leak check and make sure your throttle plate is closed all the way.

http://www.dsm.org/menu.epl?item=35

 

[95 'clipse RS]

do n/t's do boost leak tests? well i know for sure its not unplugged, and i jus rebuilt the engine in it, but there are alot of things i didnt change out like sensors and what not. and the throttle butterfly valve is closing all of the way, and sometimes it even seems as if its caught, like stuck somewhat. and why would the idle variate like it does? if i turn the headlights on it goes down some, the heater it goes down even more, and when the power steering pump is workin it bogs down some too, is it supposed to do this type of thing? its not normal IMO. no other car i have experienced has dropped hundreds of rpm's like this. what can i do? and what could it be do ya think?

thanx all for helping with this



also acutally reading that link up there i thought of something, could it be because of the ISC failing to raise the idle a little due to some drag bein upon the engine's drivebelts, like the alternator and p/s pump? that would explain why the idle drops and is somewhat intermittent. should that be something i should check into, or does it not even seem logical?

 

[Kloopofadown]

Yeah N/Ts can do boost leak tests also, I need to do one myself. You just put the tester on the throttle body. Does anybody know how many PSI is safe for a N/T?

All those devices put more load on the engine and will cause the rpms to drop, especially the A/C compressor. If your ISC is working properly, the RPMs should bump up to 800 or so RPM instead of dropping down. I would definitely test the coils on the ISC as per http://dmtalon.v8eaters.com/ISC.html.
and if it's bad you can buy one on ebay or http://www.throttlebodys.com/DSMTBs.htm
All the ISC stuff is if we're talking about your 1st Gen car, if it's about your 2G then I have no idea. Hope this helps.

 

[95 'clipse RS]

yes its the 1st gen, and thanks for replyin so quickly. the a/c compressor is disconnected, due to it didnt work anyways. the 2g's also have those motors, just no Biss screw. although the motors are different. but it actually could be the ISC motor doing this? i was thinkin the alternator was goin bad or somethin, but it still does it when i turn the wheel. sometimes jus turning the wheel makes it want to stall, like if im parking or something. so how would i go about checking this motor? is it possible to just take it off and test the coils?

so the high idle with everything like lights, heater, etc. off, could also be symtoms of the ISC motor being bad too right?

 

[Kloopofadown]

Yeah, use the link i posted to test the coils. It is possible for it to be half-bad or only work sometimes, but It sounds like your ISC is completely dead.

 

[95 'clipse RS]

thanks man, im also having troubles with the egr system, its throwin a CEL for it, and i cant quite figure that one out too. like ill reset it and sometimes it'll go days not throwin the code again, and some days it'll pop up the same day i reset it. do you have any ideas on this?

i had this problem prior to rebuilding the engine

thanks for your help man

 

[Kloopofadown]

I've removed everything emissions wise from the charcoal canister to the soleinoids on the firewall and even have an EGR blockoff plate. No CELs and I passed emissions testing with flying colors so I cant really help ya there.

Cheers

hope you get the Idle problem figured out ### down here the temperature changes affected the idle so much that it would die at stoplights.
wow it just censored the word c.u.z

 

[95 'clipse RS]

how do you not throw a CEL by doing that? i would definately like to lose this thing being that its putting so much carbon back into the intake vs. the 2g which its egr is on the exhaust side. when i had the intake off it was just caked in carbon, it was horrible, i would love losing that thing. also i noticed it has vacuum lines hooked up to it, what did you do with all of that? also did you unhook the solenoid? well i have no problems with the emissions here because emissions here doesnt exist anymore. so if you could give me some help and tips on how to do this it would be greatly appreciated.

 

[Kloopofadown]

Hmmm. Sure, I'll go outside an take a few pics and give a description of what I've done but I can't guarantee that it will rid you of your CEL. You will also lose 1 or 2 MPGs according to what I've read.

 

[95 'clipse RS]

thanks man, thats fine, im sure ive lost some anyways ### of the way its acting now. and id rather lose MPG than tear up an engine with carbon ya know? thanks alot man

also, why does it put "###" when you type the letters C U Z together?

 

[Kloopofadown]

Alright I'm gonna take some pictures tomorrow around 1pm because I'm at college right now and its a little too dark for the cellphone camera.

I have all the vacuum nipples on the Throttlebody capped off. ( there is only 1 on mine but I think yours will have 3 )

The EGR was already blocked off with a plate when I got the engine. (And it's a JDM)

All the soleinoids that had vacuum lines going to them were removed from the firewall.

I removed the Charcoal canister and routed the vent tube to the wheel well. (this is not really necessary)

 

[95 'clipse RS]

alright man, thats fine thanks much.