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Cold starting issues-ECU temp sensor?

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My most recent S15 is really struggling to start when cold, and when it does fire, it sounds like an Impreza until it is warm. It has an unmapped powerfc so I fitted a stock ECU to see if it was that. Still the same.
If it fires and you don't catch it, it'll die and not start again and reek of petrol.
I've a feeling it may be the ECU temp sensor because it runs well once it's warm. Any ideas?
 
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Tried again today and it fired up but shakes like a ****ting dog until it's warm.
Anyone know the part number for the ecu temp sensor if no one has any other pointers?
 

sibbers

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Sounds like coil pack to me mate - try unplugging and swapping them round, see if you can identify which one it is by cylinder. They usually behave worse cold and would cause unburnt fuel to hang around. Actually it sounds loads like when inket valves fail on a ca18, and SR's don't have that problem AFAIK. you would be able to check this for peace of mind with a compression test while cold.

Ecu temp sensor has normally gone the other way for me when failing ie: bad when warm.
 
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Cheers, I tried swapping them with not a lot of luck, so I'm going to put on a set of known good ones today and go from there. I get what you mean about the sensor, as they'd normally start ok then overfuel when warm, but I figured it may have been a problem as it seems temperature related.
Also, coils tend to be okay when cold and break down when hot if they're going to, so it all seems to be back to front in this case.
 

sibbers

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Not my experience of failing coils Mitch, always cold is where the problems have started for me so fingers crossed that's what your getting now. Just be thankful you don't have a CA ;) I can't really think of what else it would be except unmetered air at the plenum, or AAC or something... Best of luck!
 

Jaydej

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I have the same problem doesn't happen all the time but yeah I've put it down to a coilpack mine is on cylinder 4
 
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Sorted mine this morning. Coilpack. Good shout Sibbers :thumbs:
 
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