Hi everyone just got my first 1994 impreza wrx but theres a problem with it starting from cold it just doesnt start straght away it wants to fire up but just doesnt. It takes about a minute to start up eventually with my foot on the accelerator and sometimes wont start without a jump start once its running though it starts up fine no problem and runs like a dream.
What could be causing this? Any help would be much appreciated? Thanks Adam

 

The ECU/starting procedure requires NOT to depress the thottle.

Modern ECU-equipped cars have various sensors to tell how much fuelling/timing is required on start up.

Don't know if this is what's causing your problem, but it could be(?) Or at least conrtibuting to it(?)

 

ok sorry to sound thick but what does this mean then what will i have to replace?

 

Er... don't press the throttle pedal down when turning the engine over.

Try that first.....

 

Thanks for the quick reply ive tried that first its just it will only start with the throttle pressed so what else could it be do you think? could it be the temp sensor?

 

Yes, it could well be the temp sensor for the ECU (the larger of the two situated on the rear of the coolant crossover pipe).

They're less than £35 from Import Car Parts...

 

Ok thanks again how easy is this to fit though? Is it just a straight swap basically? Thanks again.

 

Whats the condition of you battery.

Get it checked.

 

Totally non technical suggestion here - could it be the BoV?

I have used these in the past on classics but when I fitted a HKS SSQII to my blob STi the start up from cold turned to ****. The problem went away as soon as I removed it.

 

Oh yeah the pressing foot on throttle - I looked in the hand book of my classic once and it said not to otherwise the ECU may think there is a problem and it may result in having to get the car towed to a garage to have it fixed.

 

Well the battery seems to be fine it cranks it over fine.But sometimes when its running and i put my lights on the dashboard lights go abit dim or if im putting the window down they go dim until i stop could this be the battery on its way out? Its just i thought if its cranking it over it would be fine from what ive heard could it not be the temp sensor?

 

The only thing is foz it only starts with the throttle down thats the thing its really baffled me.I mean i cant see the BOV causing that sort of problem though?

 

Maybe the throttle thing was only in the UK classics, in my new age book it doesn't say you can't do it.

As for the BoV I have no idea why, if or how it could cause the problem all I know is mine did if you have the standard re-circ then it would be a quick check.

 

Thanks for the fast reply again and i dont have the standard re-circulating one but ive been reading online that it sounds like the coolant temp sensor so ill get that changed asap and pm you to let you know how i get on.Thanks everyone for there help much appreciated.

 

Fingers crossed

 

try unplugging temp sensors and starting it like that ??

have you got standard bonnet vents as ive known this problem because of 22b like vents.

also sounds daft but try rocking the car if it doesnt start thn restart

 

tesco 99 ron fuel used to give me cold start problems.
switched to optimax and problem dissapeared.

 

Ok will try all of these lol and DJ219957 how bad was your car for cold starts off 99 ron? because mine really doesnt like starting? and how expensive is optimax these days?

 

it would try for about 5 seconds with the revs really low and then eventially settle at proper idle.

 

That's exactly what the BoV made my car do.