Bogging out during morning startup until warmed up?

[Vertigo RT]

Hey all,
Got another question... which I think I know the answer to, but wanna get some opinions.
On cold starts (car sitting for several hours), the car will run like absolute dog shit... even upon pressing the gas (and especially in gear) it will sputter and backfire until its warmed up. Upon further inspection, it turns out Ive got a pretty healthy exhaust leak from the header (one of the studs is sheered off). Would this bit of 'mismetered' air that is supposed to return to the intake cause this? When the car warms up, the leak 'tick' is gone and the car will perform nominaly.

 

[DSM1G90]

Sounds like a temp sensor isn't doing it's thing. A bad temp sensor tells the ECU that the water temp is at 77 degrees. This causes system to not start rich but at a normal A/F ratio. Take a VOM and put the leads across the temp sensor and measure resistance. Resistance will be high during cold and drop when water gets warm. If no change, sensor is gone.

 

[Vertigo RT]

Will do in the morning

 

[Mischif]

I would suspect that the idle air control valve may be acting up. At first start up the ecu by passes the o2 sensor and runs off the air maps for the first few seconds. So while a exhaust leak will cause you to run richer during normal operating conditions i dont believe it would effect it as drastically as you describe during cold starts. From my experience a faulty temp sensor causes hard starting issues, and will make it run rough due to richness until the sensor is replaced. While i dont think that is your issue it is easy to test and eliminate as a possibility.

 

[Vertigo RT]

Same effect today... but now is scanned to say 'misfire on cyl 2' once again, only seems to be an issue when its 'cold'

 

[fenixnr]

Have you tried testing your coil pack, or your ICM?

 

[Vertigo RT]

Things are getting worse, still does it REALLY bad when cold, but now does it when warm, and more specificaly when going into boost and when throttle is more than 1/3 way

 

[Vertigo RT]

Lol, thanks for all the input...
But it turned out to beeeee...... (drum roll) loose ground on the battery... ugh...

 

[robbiejohnson666]

Lol, thanks for all the input...
But it turned out to beeeee...... (drum roll) loose ground on the battery... ugh...

a loose ground? im a noobie so i didnt know that that would big a big issue my car does the same and i have changed the idle air valve and did an egr blockoff and messed with my tps and all kidsa crap was there nothing else you did?

 

[Vertigo RT]

Plugs and wires soon after

 

[asianandy87]

check the wiring on the coolant temp sensor. If you have the wires backwards it will read as the car is way below temp. As a result your car will keep dumping extra fuel and then your car will run like complete shit