# FIXED! Rough Idle, Bad cold start



## henryblank (Jan 24, 2015)

So I have had this issue for a while now,

When I try start the car on a cold morning, or if I haven't driven it for a day, it wont start first try,
then on second try it starts but idles horribly, misfiring etc for 10 seconds and then its fine. 
No issues driving after that, no issues starting for the rest of the day.

I have replaced MAF & Spark Plugs and ill be doing the thermostat this weekend(engine temp always lower than 90)
but as yet no improvement.

Any ideas on the problem? 
Coil packs? Battery? Air filter?
Could the thermostat cause this?

Cheers

H


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## Hoggy (May 8, 2002)

Hi, Replace the Coolant temp sender, ECU probably thinks engine is at normal temp rather than cold.
Similar to starting a carb engine with no choke...( weak mixture)
http://www.wak-tt.com/tempsensor/tempsensor.htm
Hoggy.


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## henryblank (Jan 24, 2015)

Cheers Hoggy,
Will give that a go!

Update, Scanned for codes and sure enough Temp sensor is broke!
Ordered it today!


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## henryblank (Jan 24, 2015)

Just replaced the coolant temp sensor for a green one.
And the situation is the exact same 

I have noticed a split hose or two while I was fiddling, cold this cause such an issue?

Cheers

H


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## Wak (May 6, 2002)

Yes a hose off the manifold will be a vacuum leak and the engine will be leaner than it should causing lumpy behaviour


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## henryblank (Jan 24, 2015)

Cheers wak,
The split is in the hose that goes from the DV to the charge pipe,

Small update, This morning the car took about 5 goes to start properly, it would start then cut out.
I had to revv it quite a lot before it got going.

Things I have already replaced
- DV
- Thermostat
- Coolant Temp Sensor
- MAF
- Cam belt/drive belt water pump etc (a month ago)

Known issues (soon to be fixed)
- Faulty N75
- Small split in n249 hose
- Split DV to Charge pipe hose

Would any of the above cause such a bad start.
surely if the split was so bad I would notice while driving. :?

Cheers
H


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## henryblank (Jan 24, 2015)

Okay so checked the hose in question, It was not split, my eyes deceive me.

Did an N249 Delete - problem isn't as bad.
is this just a placebo affect or could faulty n249 cause this?

Please help.

Cheers

H


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## 3TT3 (Aug 30, 2014)

First ,Ive no solns /ideas,what about the place that remapped the car?
Oh
I dont know if the scheme operates in Australia but check this thread ,might be nothing at all to do with your prob ,but freebies is freebies.
viewtopic.php?f=2&t=193537


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