weird start up from cold

[mikEclipse99]

when i start up my car in the mornings when its cold, it takes like 2-3 tries then once it starts it sounds like its running on 2 cylinders. it kinda sounds like a wrx that distinct sound. its weird and i dont like it and i cant figure out whats wrong. but after it runs for about 1-2min it runs perfectly fine.

 

[Boosted98gsx]

Watch your o2 sensor voltage, does is start idling properly when you go into closed loop (ie your front O2 begins to cycle)?

Mine does the same thing, but not just when its cold outside. takes it a couple minutes to warm up the O2 sensor, and then it runs perfectly.

 

[mikEclipse99]

is there anything i can do to stop this from happening?

 

[spoonman]

Could be a bad coolant temperature sensor also, here is a link with the testing procedure.

http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html

 

[ClevelandDSM]

+1 on the temp sensor

Cheep to buy, easy to change, Good to start with.

 

[mikEclipse99]

my check engine light came on when this started happening so i hit up autozone and it turned out to be: misfire in cylinder 4 due to bad plug. im in the midst of changing them right now so ill let you guys know if this solves it or not.

 

[Boosted98gsx]

Does the temp sensor have to be purchased from mitsu, or is there a cheaper source?

 

[mikEclipse99]

i changed my spark plugs and it still runs like crap. i tried my stock plug wires and it still runs bad. im confused

 

[mikEclipse99]

my check engine light showed i could either have a vacuum leak, injector fault, high or low fuel pressure, or bad plugs/wires. what do you guys think?

 

[Boosted98gsx]

Okay, I went and purchased 2 new sensors for my coolant system. Both the dash temp sender and the ecu's temp sensor for fan and startup idle control.

Did not seem to fix the issue, but I will give a definite answer after a really cold start tomorrow.

 

[mikEclipse99]

tomorrow morning im going to check my coil. i added some injector cleaner as well. if my coil is not the problem then i will have given up hope haha. ill take it to big 3 racing shop and have them fix it.

 

[mikEclipse99]

my old dsm had a bad temp sensor. it was reading that my car was way too hot when it was actually cold therefore it wouldnt start. and im not having the same symptoms at all with this car so i think i have ruled out the temp sensor.

 

[mikEclipse99]

also( i just remembered) my boost/vacuum gauge at an idle is reading around 13 hg of vacuum and i believe it should be at 17, right? could this mean i may have a vacuum leak somewhere?

 

[mikEclipse99]

turns out i have a bent valve, in cylinder 4...damn.

 

[airmail96]

damn that sucks man, at least you found your problem.