What could be causing this?

[Cerwin Vega Fan]

When I purchased my car you could tell it had a rough life by the suspension. I was kind of worried about the engine being ragged out but that doesn't seems to be a concern no more. The engine runs fine, it is not burning or leaking oil at all. But something I have noticed, when the car is pushed to WOT sometimes smoke will pour out of the exhaust. I'm not sure what it is since both times this has happen at night. I'm guessing the smoke is un burnt fuel since the injectors are suppose to be over sized. Do I sound right on my assumption or could it be something else?

[Kevin - Blown 95 TA]

what color smoke? What kind of car? What does your car have against nightime? What RU smoking?

[fastTa]

Originally posted by Kevin - Blown 95 TA
what color smoke? What kind of car? What does your car have against nightime? What RU smoking?

Damn Kev! Sometimes you crack me up.

What color smoke?!

[Cerwin Vega Fan]

I wish I could tell what color the smoke was. But their was a truck behind me and with the headlights on, the smoked regardless of what color it really was looked white. One thing I did notice was when I pushed the car to WOT (from around 20mph), the car seemed to hesitate for a second. Like it was over loaded or loading up with fuel, then the car took off and the smoke started pouring out the pipes.

[N20LT4Bird]

Hopefully its just running rich, but to be safe, you should do a compression and leakdown test on it.....

[fastTa]

Try to determine the color of the smoke during the day. If it is a blackish color, then you are most likely runnning phat (rich). If it is a whitish-blue color, then you are burning oil.

[Joe 1320]

and if it's pure white steam, that's coolant or condensation. Back in the old days, if you ruptured the shift modulator diaphram the vacuum line would draw trans oil into the engine and burn it as well. If you only notice this in the headlights of a vehicle that is behind you, my bet is a rich condition. Especially since you state at heavy throttle.

It would be helpful to those trying to help if you would state the year, model and engine.

[Jeff_in_Atl]

Originally posted by Joe 1320
and if it's pure white steam, that's coolant or condensation. Back in the old days, if you ruptured the shift modulator diaphram the vacuum line would draw trans oil into the engine and burn it as well. If you only notice this in the headlights of a vehicle that is behind you, my bet is a rich condition. Especially since you state at heavy throttle.

I had that happen on an 85 Thunderbird turbo. I put a brand new Purilator modulator valve on it. Later that night I punched it and started pouring smoke then started running pretty crappy. I checked the cylinder pressure and I got 160 out of 3 and 100 out of 1. It blew the head gasket. Ya can't compress a liquid. I called Purilator and they actually paid for me to repair it. They paid all of the parts and I charged them like $25 an hour and they paid it too.

Anyway,
If it white smoke, it water. (head gasket)
If it's black, it's carbon. (need plugs)
If it's blue, it's oil. (needs rings or valve seals)
If it's brown, it's normal.

[Cerwin Vega Fan]

Originally posted by Joe 1320
It would be helpful to those trying to help if you would state the year, model and engine.

Sorry, 1995 Camaro Z28 convertible LT1 75,000 miles.

[Joe 1320]

LT-1s are programmed to run a little rich at WOT. The reason is to prevent cat damage in extended WOT runs. The excess fuel extinguishes the cat to prevent overheating and breakup of the catalyst. Even with an oversized injector, the computer has control over the air/fuel ratio provided you aren't using an injector that is so large that the computer can't pull enough fuel out to stay within the target air/fuel ratio or in the case of a leaking injector. If you suspect an overly rich mixture, a scanner should be used to check injector pulse width and 02 sensor values. Just know that unless an aftermarket program is used the PCM, all LT1s run a little rich at WOT. (hint, hint... there's power to be unlocked with a leaner target air/fuel mixute). Hope this helps.

[Kevin - Blown 95 TA]

Originally posted by Cerwin Vega Fan
Sorry, 1995 Camaro Z28 convertible LT1 75,000 miles.

I'm betting it's just a little rich, too. You're probably seeing some black smoke for the reasons already mentioned. If it is another color, that's no good. You might, however, see some water vapor after startup and on cool days until it burns off.

Didn't mean to pick on ya too much before, but it takes a little info to diagnose a problem.