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Discussion Starter #1
I've had my new engine etc in for about 5-6 months now. And every morning (or after a long period of time) the car is rough for the first 5 min until the engine warms up.

I'll start the car, and engine temos are cold etc, and the car is hesitant and slow to rev. I've gotten used to it and just keep it below 4k until it's warmed up, and I rev slow etc etc.

Once the engine is warmed up after 5 min, the car comes alive. It revs like crazy and is really peppy, sorta like a lil kid with too much sugar.

Is this normal? Is it ok?

Any thoughts on this? It's a JDM v.8 STI engine.
 

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i imagine since less than 1% of us have a v8 sti setup...we wont be much help :). Im sure someone has to know tho...try nasoic or whatever...might be better, i know cronic on there has a similar setup to you.

-BobbyD
 

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Discussion Starter #4
Trainrex said:
Curiosity, what oil do you run?
5w30. I used non synthetic for the first 3k miles on top of the 1-2k on it from the prev owner. And now I run Mobil 1 5w30 synthetic.
 

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Not sure if it's normal as I don't have the same engine, but I would not expect full power on a cold engine.

Personnaly I stay between 2k and max 3k on a cold engine. And is usually wait more than 5min (maybe 10?)for the engine to warm up.. I don't have a oiltemp, but I know the oil takes alot longer time to warmup than water..
 

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Discussion Starter #6
Roffa said:
Not sure if it's normal as I don't have the same engine, but I would not expect full power on a cold engine.

Personnaly I stay between 2k and max 3k on a cold engine. And is usually wait more than 5min (maybe 10?)for the engine to warm up.. I don't have a oiltemp, but I know the oil takes alot longer time to warmup than water..
I have the oil temp gauge and I wait till the temps are up which usually takes about 5-10 min. I will drive at 4k and leave it there till it warms up.

It's as if it stutters, like it's just waking up, then it wakes up and it's great. Maybe the JDM engine has a rougher cold start then the USDM 2.5:confused:
 

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Discussion Starter #7
Another thing to add. When I installed my engine, most people were confused as to a wire on my engine that they said should only be on the spec-c.

It's two wires (red&green) right below the throttlebody. They said it's an intake temp sensor and that it should only be on the spec-c but that my engine will work fine without this being plugged in.

This is info I received from many high sources.

My thoughts are that this could prolly be the reason for my rough cold start. That the temp sensor is there to help with cold starts etc...
 

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DEADPOOL said:
Another thing to add. When I installed my engine, most people were confused as to a wire on my engine that they said should only be on the spec-c.

It's two wires (red&green) right below the throttlebody. They said it's an intake temp sensor and that it should only be on the spec-c but that my engine will work fine without this being plugged in.

This is info I received from many high sources.

My thoughts are that this could prolly be the reason for my rough cold start. That the temp sensor is there to help with cold starts etc...
Very true, she could be running a tad lean on startup.
 

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DEADPOOL said:
It's as if it stutters, like it's just waking up, then it wakes up and it's great.
Not sure.. But what ems do you use? the jdm car is not optimized for the low quality fuel you get in the US :confused1

But having that said my car act alittle strange when it's cold to.. Not much and it's no problem as it run nicely, but everything feels alittle strange untill it warms up.. I guess it's normal :rolleyes:
 

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DEADPOOL said:
Another thing to add. When I installed my engine, most people were confused as to a wire on my engine that they said should only be on the spec-c.

It's two wires (red&green) right below the throttlebody. They said it's an intake temp sensor and that it should only be on the spec-c but that my engine will work fine without this being plugged in.

This is info I received from many high sources.

My thoughts are that this could prolly be the reason for my rough cold start. That the temp sensor is there to help with cold starts etc...
just add info.
Yes, your engine are stock on Spec C car (japan), just like mine here. Yup, same as mine here. It will rev after ignition, for about 1500 rpm, smooth. And then, the RPM will drop for around 600-750RPM. And it smooth idle.
 

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It's normal, since your car probably doesn't have the fully restrictive tumbler generator valves that the US cars have. I wouldn't worry about it since proper warmup for at least 15 minutes should be part of the driving sequence any time you plan on reving past 4k rpm....I wouldn't dare flogging my car without it being absolutely perfect....the gas octane difference may also be a factor.
 

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Discussion Starter #12
Timdog1650 said:
It's normal, since your car probably doesn't have the fully restrictive tumbler generator valves that the US cars have. I wouldn't worry about it since proper warmup for at least 15 minutes should be part of the driving sequence any time you plan on reving past 4k rpm....I wouldn't dare flogging my car without it being absolutely perfect....the gas octane difference may also be a factor.
Thats something I didn't think of, the lack of TGV's.

I run 93 octane, the car is meant for about 95-96, but the ECU adapts by pulling timing.
 

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lean on startup? dont you mean rich, i always thought cars/motorcycles ran rich on start up, when i would ride my TL1000 cold it would smell like gas real bad untill it warmed up, same with my old beater car, dont know about my new car, i always give her 10-15 min
 

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My engine does the same thing in the morning, the first 3 to 5 min, it runs a little rough till it starts to warm up. After that I am good. I always thought that it was the norm. I always heard that our motors, even the motors that we here in the staes didnt get would do that. Just part of the design???

caelin~
 
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