Well I drained my oil out of the Bro today and I have to admit that I was quite late but I noticed that there was a pretty little group of rainbow colored bubbles on the top of the oil...After I was done admiring the pretty little fellas I got back to reality....This could be the injectors screwing up. So I pulled my plugs and noticed for the first time ever that they were quite black and even had some paper thin carbon deposits on them....

Now if you remember, I told you that there was black smoke bellowing from the tail pipe and after the mornings first start it would do the rough idling and smokey thing for about 30 seconds or so and then flatten out...It would do it all over again if I turned the key off and started it again no matter what the engine temperature....

So my question to you is how do I go about linking the injectors to this nasty little problem if they may be the culprit I have them out and cleaned and have purchased a new "O" ring kit but would like to know how to diagnose them so Im not just putting them back in there to get carboned up again. Or might the problem lie elsewhere...This engine seems abnormally dirty and this is the first time I think it has ever been decarbonized so I would like to do things right, it deserves it.

 

idk, sounds like maybe your O2 sensor is crapping out. I guessing the 30 second thing is from the o2 sensor cooling down, and giving in acurate readings until it heats back up. Normally the ho2 (heated oxygen sensor) dosent work that well upon start-up, but not bad enough to make black smoke and all, which is why this motor needs its little time to warm-up....maybe the one in yours is going bad and is giving very in-acurate readings until it fully heats up.

 

O2 sensors don't work at all until they reach about 600 F, which does take a few minutes. The computer is programmed to ignore the O2 sensor at initial startup until the O2 sensor starts to send out a signal (so called "open-loop" mode). It shouldn't be running overly rich during this time unless something else is wrong.

The main way the fuel injectors would contribute to running rich is if they weren't closing completely. Electrically, this could occur if there was a short to ground between the injectors and the computer. If it's a mechanical failure, I wouldn't expect it to effect all of the injectors at the same time. Was the carbon deposits uniform across all cylinders or isolated to certain cylinders?

With the fuel rail in the vehicle, you investigate this scenario using a fuel pressure gauge. You pressure up the fuel rail and shut the pump off. If the pressure in the fuel rail drops off quickly, then there's a leak somewhere, one possibility being through the injectors. I'm not sure if you can pressure up the fuel rail with the rail removed. It seems like you did a pressure test, do recall having trouble with the fuel rail holding pressure?

More common than injectors leaking is to have the FPR leaking fuel into the intake. I can't remember if you've looked into this possibility already.

Other ideas: If the ECT is reporting a seriously erroneous temperature, the computer won't set the initial fuel mixture correctly. I would expect this to throw a code, though. ECT is a simple thermistor and shouldn't be too difficult to check.
A bad TPS could cause the computer to think you are pressing the throttle. This may or may not throw a code. TPS is a simple potentiometer and not too difficult to check.
If the MAP were unhooked from the intake, or the vacuum line plugged, or other problem, the computer could attempt to dump excess fuel in. This may or may not throw a code. MAP is easy to test if you have a frequency counter.

It seems like you've already pulled codes, but I can't remember. If you haven't, then I would certainly pull them.

 

The gas pump shuts off by a pressure switch right? listen for your fuel pump when you turn the key on....but dont start your motor. It should turn off for no more then about 2 seconds.....if you hear the fuel pump kick back on after the first time it shuts off, that will indicate there is a leak lowering the pressure for the fuel pump to turn on and off.

 

Incorrect. The computer operates the fuel pump on a timer when the key is first turned on. If the computer doesn't see a TACH/PIP signal from the ICM in those few seconds, it shuts the pump off, regardless of the pressure (the computer doesn't monitor the pressure at all). Once the TACH/PIP signal is received, it starts running the fuel pump until the TACH/PIP signal goes away. Fuel pressure is controlled by a purely mechanical back pressure regulator.

 

thats true, you wouldnt hear it each time you turned the key on anyway if it was on a pressure switch.

You sure the computer controls it, and not just a relay, connect to the tahc/pip signal.

Dose it jut turn on for a second to let you know it works?

 

I guess it depends on how you look at it. If you want to think of it this way, recognize that the connection between the tach/pip and the fuel pump relay is made in the main computer.

The fuel rail isn't expected to remain pressurized when the engine is off for an extended time. The pump(s) run(s) briefly when the key is first turned on to bring the fuel pressure up before starting.

 

oh, well if it runs through the ECU, then i consider it "computer controled"...i just didnt know if it was seprate from the computer and was just controled by a relay and timer.