93 subaru imprez.when warms up it starts

Check coolant temp sensor and IAC.

Clean your IACV and throttle body butterfly valve, get throttle body cleaner at any auto parts shop.

Test plug leads with a Ohm meter, when the resistance is higher then 8k Ohm, replace them, check also the coil for traces of arcing out. Check spark plugs cq replace them.

What is the vehicle - especially the age. There are many things that can cause this and age has a bit to do with it.

Let me know - it will make it easier to answer.

Sorry - I didn't see the vehicle information the first time.

Let me research this - i will get back to you soon.

I Have a couple of questions. First question does engine surge when idleing cold? 2. Does engine start quickly without a lot of cranking, Cold or warm? 3. Do you have funny smell at highway speed, or after you stop? With out this info and your imput, I would only be guessing. I am retired mechanic of 25 years. and would like to help if u need me.

it may be idle control sensor or a bad mas air flow sensor--maf sensor in otherwords. or could be engine misfire at cold temp. start. only time when cold? or does run better when warm? try warming engine to operating temperature before driving,if problem removes it's self after warm up,up grade gas to 93 octane for 1 tank full. then see if problem goes away. it's cold where you are right? if so the fuel needs to be at least midgrade 89 octane fuel because 87 octane fuel will not start your honda correctly at cold temps. in cold weather 93 or super gas octane will start ,no problem,low octane fuel sometimes gels, or freezes at low temps. if in warm climate, change the fuel filter, add fuel injector cleaner to your fuel tank[preferablly lucas fuel treatment] this will lube your fuel injectors and give better fuel mileage. thank you for choosing fixya.com

ok ,im really not shure buthey ... look at the oil presure senssor or oil pump that coul be the problem if pump not good ...cant build pre4ssure enoughf then senssor turn the engine off ...thats why car will stay on wen you press gas...senssor could also be defected and give the same order to engine ...
wen you put switch on without starting engine ...wen all dash lignt go on ...you see oil lignt go on??????

there is an idle valve on the throttle body. it opens to keep a cold engine running, then closes when the engine warms up. if it sticks open, car will run good for a few seconds then stall the warmer it gets

If you have a stock carb those things have a million vacuum lines and if they are old and stiff and cracked that can also affect it. also look at your intake gasket and maybe replace it. My car had similar problems and i replaced the vacuum lines and intake gasket and it runs and idles great. good luck