Hi, Can someone give me some advice. My subaru wrx 1996 import has a problem starting when cold. it starts but the revs are so low for the first 5 seconds (200 - 300 rpm) and so sort of chokes and then goes off. Once warm and for the rest of the day it starts okay. It does this mainly in the mornings. Anyone have an idea what i could look out for.
thanks

 

When was it last serviced? Fuel filter, plugs and air filter i would look at as a starting point as they arent expensive to replace. Does it drive ok other than this?

 

Thanks for your response. I changed the oil and checked plugs about 5 months ago. Plugs were okay so didnt change them. Changed the fuel filter and air filter though. This actually started when i changed to shell vpower fuel. I disconnected the battery to reset the ecu as i read in some posts but problem persists so i thought maybe something else is causing it.

 

Crank sensor and coolant temp sensor can also cause starting problems (crank though would have be all the time not just when cold i would have thought).

www.scoobypedia.co.uk under the ecu heading has a manual way of testing for error codes.

 

+1 for coolant temp sensor.

Just changed mine for various reasons, bad fuel economy ( read worse than usual ) dodgy starting when hot etc.

The difference is massive & the car is generally so much better, definately not imagining it.

Easy job to swap & doesnt cost much ( £20 off fleabay )

definately worth a try

 

Ok. thanks I will run a diagnostic just to make sure then change the coolant temp sensor. AM sure it throws a code, doesnt it.

 

It should throw up a code BUT if it doesn't take it to a garage that has a 'Select Monitor' (old subaru diagnostic tool) to make sure, as my temp sensor was going wrong but didn't illuminate the CEL but was picked up on the Select Monitor

 

sounds like you have the same problem as me, see my thread "ggrr.. still got cold idle issue" i have tried cleaning icv, i have just ordered a new coolant sensor.
my cel light has not come on and i have not got any fault codes stored.
the cel will only light or a code will only be registered if the sensor fails to give a signal atall. i think my sensor is just sending the wrong signal.

 

Thank you all for your responses. I am hoping to get time this weekend to run diagnostics see what comes up. Might just order the coolant sensor. Will also check the plugs. Any more ideas of anything else i can check / change while am at it? Is it worth resetting the ECU using the diagnostics?

 

ive changed my coolant sensor today. £10 from ebay. so far so good. took about 30mins start to finish as i took the air box and turbo pipe off and a few other bits. will know in a few days if its worked after a few cold starts.

i also checked the turbo shaft for play while i was in there. i wish i hadnt! its got quite a bit of play. bummer.
you fix one problem and find another.....

 

Thanks for the update. I didnt get a chance to change mine this weekend so i will wait for your update after a few days and if its now behaving i will go ahead and change mine.

 

Hi all, thanks for your help. I changed my temperature sensor and the starting problem on cold mornings is now okay.