IROC-Z5.7TPI

Well my car has progressivly been getting worse, when i start it i almost always have to push on the gas and some time it will die off, and other times it will idle really rough and sound like it has a HotCam in it or somthing. Also the whole time it lets out black smoke, while its running rough. I checked timing its at TDC which is what a 350 TPI should be and have new cap and rotor, plugs, and wires, compression check comes out fine on every cylinder, and fuel pressure check came out good, also the fuel filter is brand new. The car has its oil changed with Mobil 1 synthetic every 2500 miles and i had my Injectors cleaned about 2 oil changes ago. My mechanic told me that my Catalytic converter is most likly shot and am getting that done within the next few weeks, along with my flexplate which is starting to get loud. Also sometimes when i go full throttle that car will almost die, then go to the normal RPM, and alot of times smoke will shoot out the exaust. I was looking through some other posts about similar problems and someone said something about and O2 sensor possible being a problem along with the Coolant temp sensor, both of which are brand new on my car.

Any help would be greatly appriciated.
Thanks,
Joe

Maverick H1L

iTrader: (8)

You have way too much fuel going into the chambers. It's possible that when the injectors were cleaned that some deposits that were keeping the injectors operating like they should, or from leaking, were cleaned out and now they leak. Black smoke from exhaust=WAY too much gas going to the combustion chambers.

IROC-Z5.7TPI

If that is the problem, is the only way to fix it to replace all the injectors...?

Thanks

83 Z28 HO

hmmm black smoke, means your burning fuel in exhaust, aka rich. He could be right about injectors, can't say much there, but your running VERY rich.

Maverick H1L

iTrader: (8)

Not exactly. Usually the cold start injector (if you have one, located in the absolute worst place it can in the back of the intake manifold) is the first one to go. Maybe if you removed the fuel rail and connected a 12VDC source between ports A and G (top right and bottom left corners) of the ALDL connector, turning on the fuel pump, you can tell which is leaking. It might also be that you are drawing fuel in through the evap canister (can by the air filter) vacuum lines because the can is crap. I have no way to tell and I am running out of options myself.

430T/A

I went through the same problem with my car a few weeks ago. when I started it would put out very thick amounts of black smoke. it looked like silk it was so balc. turns out cold start valve was stuck open. I also had a faulty mass air flow sensor as well.

Maverick H1L

iTrader: (8)

I wish I could figure where my righ prob was coming from. The plugs look like crap, the engine runs like crap (when it runs at all), and to top it off, I have no black smoke in the exhaust, not even when I had the straight pipe intead of the cat convertor. I'm totally stumped!

IROC-Z5.7TPI

Well to bring it up, i only got to change 7 of the spark plugs, the only one i didnt was the one on the back of the passenger side, maybe that could be the problem, i didnt have time to do it when i changed the other 7 because how hard it was.

Maverick H1L

iTrader: (8)

In my experience, whether I changed all six or just two of the plugs didn't matter, the condition persists... I just hope I can run the engine long enough to put the car in the garage for the winter once I finally get that new ECM...