Thick white smoke and gas coming from tailpipe

Hi Roy,

Sorry for miscommunication above: I measured PCM wire voltage of 3.4V with the fuel
injector connector totally disconnected from the injector.

Due to the short I had, I am able to connect and disconnect easily the PCM wire near the fuel injector connector (not at the PCM, I do not know where to tap it). In this case, per your suggestion, with key on, engine off, I get 12 volts reading on PCM wire when it is connected and 3.4 volts when it is disconnected.

1)So looks like PCM is good (allows the injector to pull PCM voltage to 12 volts), injector resistance is good. Can you tell me where to tap the PCM connector, so I can check the PCM wiring on cylinder 1?

2)Do you think any of the PCM issues could cause a little bit of fuel smell near the engine block? Perhaps, it might be that over tighten spark plugs broke.

3)For how long can I run the engine with fuel and white smoke in exhaust system before it goes bad? I am thinking I might simply have a lot of residual fuel in the exhaust system I need to clear, but I am afraid to run the engine for too long and ruin catalytic converter, engine or something else.

Thank you,
Gene

There are 3 PCM connectors there, which one is it? And in which corner is the pin #1? Thank you.

Great. I got the 12V. I measured practically no wire resistance from PCM to fuel injector as well. Wiring is good. Not sure what to do now.

I pull the error codes. File is attached Looks like cylinder 3 is the cause of the problems.

I pull the codes for the first time and it showed the above number 3 problem. I replaced the spark plug and coil assembly on number 3 with new ones. Started an engine, it sounds normal, for a 30 seconds or so it looked like the smoke was clearing up and then it started to smoke up heavy again. Anyway, I cleared the above codes, idle an engine for couple of minutes and tried to get codes again. And none are reported while thick white smoke is pouring.

1)For how long typically do I need to run an engine for the codes to get reported?
2)For how long typically do I need to run an engine to clear the gas inside of the exhaust system? (Initially gas was dripping from tailpipe, now after the above spark plug/coil assembly change on 3 it does not drip). On cylinder 1 PCM wire was shorted to ground 3-4 minutes before I shut down the engine and found the short, not sure how much gas it would flood into the system.
3)Do you know if PCM fuel injector pins are designed to handle to be shorted to ground and not ruin the PCM? Would fuel injector get damaged if it has continues 12V across it for 3-4 minutes?

"As far as number 1, if that is what is causing the excessive fuel, the PCM is bad."
4)Why do you think that? PCM is measuring open with key on and voltage on the disconnected PCM connector is pulled to 12V. For whatever it is worth, all PCM wires seem to behave identical: reporting 3.4V with fuel injector connectors disconnected; engine sounds smooth as well.
Thank you.

Good morning,
I measured PCM wire voltage of 3.4V with the fuel injector connector disconnected from the fuel injector. Since PCM driver acts like an open, it was an irrelevant measurement, easily effected by the impedance of my multi-meter. What matters is that PCM driver acts properly like an open with key on, engine off.

"With the key on, engine off, you should have 12 volts from the common feed and 12 volts on the wire to the PCM. That means the PCM driver is open and there is no ground."

"I would disconnect the PCM and check the voltage of the wire from the effected injector at the PCM connector. If it is 12 volts, then you have a bad PCM. If you have any other reading, it is either the wiring or the injector."

Therefore, I do not see how your conclusion can be correct: one on hand 12V reading indicates proper PCM function (PCM driver is open, for all practical purposes it is the same as disconnecting PCM connector), on the other hand 12V reading with PCM disconnected indicates bad PCM.

"Where was the short for number 3 cylinder?"
There was no short on number 3 cylinder. I am not able to get any error codes, after I replaced coil and spark plug on 3.