leblanc1

iTrader: (2)

My LS2 in my 68 Chevelle runs pretty great. It's SD tuned. Lately, it's been extremely difficult to start after sitting for a day. It will come to life on the first turn of the key then immediately die. Then it takes a lot of turning it over with added throttle to get it started and during that process it's smoking white. Once it starts again...it runs rough, billowing white smoke for a bit...then all is well. What's the deal?

My tuner mentioned maybe a leaking injector?

Gasoholic

iTrader: (1)

I've had injectors cause that.
The motor starts cause theres fuel in the cylinder but it stalls because the pressure fell off. After cranking it the pressure comes back it starts and may run fine.
I also had a pump/sending unit cause a similar symptom once. The pressure would fall and the fuel would drain back into the tank. After cranking a bit it would come back up and start. But it didn't smoke.

Millenium Z06

Sounds like coolant is pooling in the cylinders fuel would give you black smoke

leblanc1

iTrader: (2)

I agree with what you're saying, but at the tailpipe...it smells like pure raw fuel.

What's the best way to inspect for symptoms?

jacko jeebus

iTrader: (1)

Have an injector bleed down test done with a tech2. It pulses all injectors and you can read the pressure drop on a gauge. Compare the results to other injectors to see which is at fault.

jeffs55chevy

i had a 4runner 22re that would leak antifreeze into the combustion chamber overnight. it would idle rough at first startup and then clear up after a few seconds along with the white smoke. you could do a leakdown test.

dreadpirateroberts

iTrader: (1)

black smoke is SOOT.

white smoke is any kind of liquid vapor - coolant, water from combustion, or unburnt fuel.

G Atsma

If the white "smoke" reeks of fuel, you have injector issues.
If not, you have a bad head gasket or cracked block/head.

leblanc1

iTrader: (2)

The smoke at the tailpipes is rich with fuel smell, definitely.

G Atsma

At least now you know where the problem lies....

Gasoholic

iTrader: (1)

The color of the exhaust fumes could be coincidental. Could be just moisture in the exhaust system from short run times. Dont know not there to see it in person.
Symptoms sound like fuel system.
Either way need to do some further diagnosis.
Whats the coolant look like? Are you losing coolant? Does the system hold pressure? Any white streaks in the oil fill cap, or dip stick?
As said before, need to check fuel pressure, pressure drop.