hard start problem

[embai]

Hi guys,

having a weird starting issue with my car lately, during starting, the car will keep on cranking but will not start, if it start it will stalls straight away like theres not enough fuel...always start when cranking second time but will idle very low for few second (misfiring) then suddenly to the normal cold starting rpm 1.5k to 2k rpm..(this will only happen when cold, once it starts up, its fine for the rest of the day, start first pop)

car is a nz new v9 sti, cant seems to figure out what is the problem, the car drive fine and boost fine, just first start in the morning... car doesnt throw any code...

was thinking of getting a obd scanner? (which i assume would cost an arm and a leg)

thanks

[crazymf]

Could be a faulty temp sensor. This would cause hard starting when cold and would have no affect on performance once the car has warmed up...

[embai]

which temp sensor would it be? would bad coolant temp sensor cause this? or something else?

[crazymf]

Its located in the cross pipe thats under the inlet manifold, can be accessed by removing the alternator. It'll have a 3 wire plug going to it. Yes a faulty temp sensor can cause hard starting when cold. It tells the ecu how cold the engine is and will richen up on cold starting. If its not getting the right signal it'll revert back to the normal hot running fuel curve, which is quite a bit leaner, hence why its hard to start when cold...

[Guest]

few things that need to be checked are

fuel pressure (does it hold rail pressure overnight?)

does it fire initially? in which case coolant and crank sensors OK (which would indicate mass air sensor fault)

Have had 2 V7's before with similar cold running issues, turned out to be coil packs

Has the cold temp alignment been tested of colant sensor

[stira]

My old v3 STI did a similar thing except not when cold. It would normally start first pop in the morning but when you went to start it 4 hrs later, when i went home for lunch, it would turn over as normal, hiccup, then turn over and start.

It never got any worse the whole time I owned so I never worried. But i would stilll like to know what it was?

[Guest STiEVO]

GLOW PLUGS

[embai]

glow plugs... ;D

i tried again this morning, i let it have a longer crank, it did start but stalls immediately, then i tried the second time, it start up straight away, like i said, it only happen when it is cold... pretty weird problem though cars only travelled 35k, wouldnt expect coils to fails that quick?????

cheers

[QRAF]

i have a similar issue i have put it down to the leads and coil and i'm going to do the spark plugs at the same time.

just have to find some blue leads to match the engine bay lol ;D

[Guest]

Correct diagnosis proceedure will make sure you dont end up wasting your hard earned $$

[embai]

a small update, while i havent had the time to get around to check the stuff, i do found that for the last two days during cold start, the car can start after a few cranks but still sputter like want to die but will eventually come to life...

bad tank of gas???

bad afm?

cheers

[Guest STiEVO]

ITS THE GLOWPLUGS!!!!!!!

lol

[embai]

 STiEVO said:

ITS THE GLOWPLUGS!!!!!!!

so you are saying its the spark plug and i should change them? ???

lol

[Guest boostcut]

have you started it today??? have you tried turning ign on then give it a short crank to start fuel pump and wait for it to prime then turn over to start? give that a try....

[Guest]

Pump will prime for 2-3 sec when ign turned on all by itself

[embai]

small update... here regarding the problem

had been busy and away for the past few months

i've have disconnected the battery while i am away and when i am back

the car fired up first pop, first crank

but now the problem is slowly coming back

still figuring out what is the problem

there is no check engine light, the car is standard, everything is fine apart from starting it first thing in the morning

any ideas??

[Guest boostin]

Take it to a Subaru garage and get it checked / fixed.

Too hard to diagnose problems over the net.