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Discussion Starter · #1 ·
My car will not rev above 2.5K when cold.
Now I have noticed that it happens at exactly the point when the boost gauge goes across the half way point, vacumm to boost.
If I try to push the car into going it just splutters and coughs. Below 2.5K it runs fine and also runs fine when warmed up.
Could it be anything to do with the turbos not spooling up, due to cold oil etc.
I know that I am not supposed to go on boost before it's warm anyway and I don't, but this cannot be right.
 

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I use NGK 7's never had a problem. try a set of 7's

Have a look into cleaning your afm's (or finding another set of AFM's to try out for cold start) or that your ECU is pushing in too much fuel at cold start

Another good check up would be your vacume lines make sure you dont have a leak somewhere.

These are all the faults that may lead to your cold start problem I can think of to be honest.
 

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std or aftermarket ecu? If std it could be a dodgy coolant temp sensor reading too low causing excessive enrichment. If its aftermarket it could be the cold start enrichment is pooh!

MAF`s have no effect cold to hot running.....
 

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Aye nice input I really wanna what is causing it my 2p is gonna be something really small n stupid :)
 

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Discussion Starter · #8 ·
Standard ECU and all standard turbos, internals etc. Well, I think so anyway.
Any way of actually testing the coolant temp sensor?
 

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had exact same problem. was the bottom AFM. replaced with a reconditioned one.. fixed the issue with not going above 2.5k

then the spluttering, popping etc was to do with the inlet manifold gasket leaking in the 5th cyl.. It wouldnt be as noticable when warm because it would seal better, but never idled totally smooth, just better when warm.
 

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Discussion Starter · #11 ·
mine does it too, just don't run boost till its warm.
lol. I don't mate, honestly. Though it can be a bit worrying when crossing a dual carriageway at morning rush hour and I can only rev to 2.5K before having to change gear.
I find myself thinking 'sorry, yes I know I have a supercar but it won't go any faster, yet!' :chuckle:
 

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All this talk about hessitation below 2.5k got my car in paranoia mode as mine is hessitating now as well but I think that is due to my 1 year old spark plugs. and not to mention thinking of getting the HKS Spark Amp
 

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Discussion Starter · #13 ·
Well, I cleaned the AFM's today. I won't find out if it's cured the cold running issue until the morning, but warm it runs a lot more smoothly. They were both quite dirty, the bottom one especially so. Gave everything a good clean with carb cleaner and blew out the filters with an airline.
 

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Discussion Starter · #14 ·
Cured! :)
It still has a very slight misfire but will now pull on boost if I ask it to, even when cold. I can't comment on the above post about AFM's not having any affect at cold running, but my problem has definately improved massively by cleaning them.
 

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....meaning that they do not behave any differently hot to cold. Any metering issues you had due to dirty sensor would have been apparent hot cold (if you drove in the same speed load area`s.....).

Glad it was an easy fix!!
 
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