Hiccup during startup

[NICONick]

Ok so recently, when I go to start my S14 in the morning it hiccups and the idle fluctuates for about 5-10sec and then idles fine. Any ideas? Seems that the colder it get here in NJ the worse the prob is and it only does it after sitting for hours.

Btw it's a ka24de-t with
Garret T3/t4 Hybird .48 a/r 57 trim
IAP tubular equal length Manifold
IAP Intercooler 28"x8"3"
Tial 38mm Wastegate
Greddy Type RS BOV ( recirculated )
370cc injectors
Walbro pl255 H-Flow pump
Apexi SAFC-2
IAP Downpipe + Megan racing stainless steel downpipe
Summit racing 4cylinder heat blanket and header wrap/relfective material
Autometer Phantom Boost gauge
Apexi N1 3" exhaust
Hayden 404 transmission cooler
among others...

Any ideas?

[Hoffman5982]

Pretty much all older cars run weird in the winter

[NICONick]

Pretty much all older cars run weird in the winter

So, just chalk it up to an old car in the winter? Hmm...

[badbob2121]

Well you really haven't described this issue very well for us to understand. A fluctuating idle can be cause by many different issues. You should try and record a video of the problem and post it here so we can really see what is happening, and be as descriptive as possible...

[NICONick]

Well you really haven't described this issue very well for us to understand. A fluctuating idle can be cause by many different issues. You should try and record a video of the problem and post it here so we can really see what is happening, and be as descriptive as possible...

OK well that will have to wait until the morning bc like I said it only does it after sitting for a while and I have been out in it already...

I mean when I start it the idle goes back and forth from below 500 to above 1k, only has stalled from it once, and it idles fine after 5-10 secs..... not sure how much more I can describe it.

[NICONick]

here is the video.... the knocking sound in the video is the exhaust rattling, i must have a loose hanger or something, that sound has nothing to do with the idle... what do you guys think?

*Sorry for the few seconds of radio background noise

http://vimeo.com/34099355

[kouki munster]

A dirty/sticking iacv is the most likely culprit, but a coolant temp sensor that is starting to show its age is another possibility.

[OutToWinPAHC]

A dirty/sticking iacv is the most likely culprit, but a coolant temp sensor that is starting to show its age is another possibility.

This or check your plugs and timing. Chances are you have no emissions anymore and that can also account for some of the cold start issues.

[NICONick]

A dirty/sticking iacv is the most likely culprit, but a coolant temp sensor that is starting to show its age is another possibility.

This or check your plugs and timing. Chances are you have no emissions anymore and that can also account for some of the cold start issues.

Nope! No more emissions, however, this morning during start-up I noticed a small puff of blue smoke which I know means oil... but I don't notice any blue smoke while driving or after warm-up or anything...

What you think?

[biggie]

Old engine without any head upgrade? Normall for the valves to start leaking a little when it sits, that the normal cause of puff of smoke at start up.

[NICONick]

Old engine without any head upgrade? Normall for the valves to start leaking a little when it sits, that the normal cause of puff of smoke at start up.

Yes, old engine with 91k orig miles on it, with no head upgrade. The car sat for a while (6-8mos) before I bought it. So, is this a serious prob or what can I do to prevent these leaking valves? Could this be causing my fluctuating idle at cold start?

[biggie]

Shouldn't be related to the idle at start up. Could try adjusting the valves, otherwise its not a big issue unless it gets to the point where it is smoking constantly (if you notice everytime you move from a stop it smokes).

My both of my KAs fluctuate idle at first start up, both NA and T, but I just let them warm up and don't pay it any attention.

[NICONick]

Shouldn't be related to the idle at start up. Could try adjusting the valves, otherwise its not a big issue unless it gets to the point where it is smoking constantly (if you notice everytime you move from a stop it smokes).

My both of my KAs fluctuate idle at first start up, both NA and T, but I just let them warm up and don't pay it any attention.

Yeah, how would I adjust the valves? Yeah once it warms up it runs great! It's just on those cold start-ups

[biggie]

Can research adjusting valves I'm sure their should be a writeup somewhere.

[kouki munster]

Adjusting the valves will not solve the smoking issue, to do that you will need to replace the valve stem seals. There is also not a whole lot you can do to adjust the valves on ka's with out the proper shims and tools to measure the clearance.

[OutToWinPAHC]

Adjusting the valves will not solve the smoking issue, to do that you will need to replace the valve stem seals. There is also not a whole lot you can do to adjust the valves on ka's with out the proper shims and tools to measure the clearance.

[NICONick]

Ok, a little update, so as the weather gets colder the problem seems to be getting worse. Now during startup it will start for about 2-3 sec and then stall. Then it cranks, but doesn't start right up, I have to give it gas for it to start and give it a little gas to keep it started for about 5-10sec, then it stays started fine.

Because of the colder weather, do u guys think it could b battery related?

[biggie]

Still sounds like dirty IACV and/or vaccum leak.

[NICONick]

Still sounds like dirty IACV and/or vaccum leak.

Wouldn't a vacuum leak b something that's constant? Not during startup? (just guessing)

Also, how would the drop in temp affect a vacuum leak and/or dirty IACV? The idle stays strong once the car is warm, does dip when coming to a stop or anything like a typical dirty IACV

[biggie]

The engine being colder itself would make it a little harder to run compared to warm weather on a cold start. Just intesifing the IACV affect.

Yeah, normally I would think that a vaccum leak would show up constantly. Would just check all of your emission removal points to be sure everything is sealed off.